Potassium in nutrition and human health: Difference between revisions
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To maintain [[Life|life]] and [[health]], the diet of humans must contain the chemical element, | To maintain [[Life|life]] and [[health]], the diet of humans must contain the chemical element, <b>[[potassium]]</b>, in its ionic form (K<sup>+</sup>), usually consumed as potassium salts of organic acids in food (e.g., potassium citrate), found most abundantly in non-grain plant foods (vegetables and fruits). | ||
In 2004-2006, and again in 2010, the ''Institute of Medicine of the National Academies of Science'' <ref name=ottendribook>Otten JJ, Hellwig JP, Meyers LD (editors) (2006) Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. National Academies Press. Pages 370-379. ISBN 0-309-65646-X</ref> and its ''Food and Nutrition Board'' <ref name=napdri04>Panel on Dietary Reference Intakes for Electrolytes and Water. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Food and Nutrition Board. Institute of Medicine of The National Academies (2004) [http://books.nap.edu/openbook.php?record_id=10925&page=186/ Dietary Reference Intakes For Water, Potassium, Sodium, Chloride, and Sulfate] “Potassium” pp. 186-268. The National Academies Press, Washington, D.C.</ref> <ref name=ai-k>[http://www.dietaryguidelines.gov Dietary Guidelines for Americans, 2010]. [http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/PolicyDoc/PolicyDoc.pdf PDF (p40]. U.S Department of Agriculture. U.S. Department of Health and Human Services.</ref> recommended that adult humans consume 4700 milligrams (mg) of potassium per day, or more, which, calculated from the atomic mass of potassium (39.1 mg per [[Mole (unit)|mmol)]], corresponds to 120 millimoles (mmol) potassium per day: 4700 mg/39.1 mg/mmol=120 mmol. That recommended intake of potassium substantially exceeds estimates from recent surveys of average intakes by the general population, raising the possibility that a persisting state of suboptimal body potassium content, and rate of the body throughput of potassium, prevails in the general population. <ref name=03-04K>[http://www.ars.usda.gov/Services/docs.htm?docid=14958 What We Eat in America, NHANES 2003-2004, Tables. 1. Nutrient Intakes: Mean Amounts Consumed per Individual, One Day, 2003-2004 (Downloadable PDF File)]</ref> <ref name=05-06K>[http://www.ars.usda.gov/SP2UserFiles/Place/12355000/pdf/0506/Table_1_NIF_05.pdf Nutrient Intakes: Mean Amounts Consumed per Individual, One Day, 2005-2006.] U.S. Department of Agriculture, Agricultural Research Services, Fast Facts, Reports/Articles, and Tables (2005-2006).</ref> <ref name=eatk2010>[http://www.ars.usda.gov/Services/docs.htm?docid=18349 What We Eat in America, 2009-2010]. USDA. Downloadable pdf Tables.</ref> Underconsumption of potassium reflects the general American dietary crisis of under-consumption of healthful nutrients and over-consumption of unhealthful nutrients and nutrient-empty calories.<ref>Krebs-Smith SM, Guenther PM, Subar AF, Kirkpatrick SI, & Dodd KW (2010) [http://dx.doi.org/10.3945/jn.110.124826 Americans do not meet federal dietary recommendations]. J Nutr 140(10):1832-1838. PMID 2937576.</ref> | |||
Subsequent sections will discuss potassium intake recommendations for children and special groups, as well as more recent perspectives on the 'optimal' requirements for dietary potassium in humans. | Subsequent sections will discuss potassium intake recommendations for children and special groups, as well as more recent perspectives on the 'optimal' requirements for dietary potassium in humans. | ||
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Potassium ranks as the most abundant cation (positive ion) inside animal [[Cell (biology)|cells]] (intracellular), and as such contributes critically in numerous important ways to the optimal functioning of cells and therefore to optimal functioning of the organ systems and individuals they compose. Among other metabolic functions, potassium plays a role in the synthesis of proteins and in the biochemical transformations required for carbohydrate metabolism. | Potassium ranks as the most abundant cation (positive ion) inside animal [[Cell (biology)|cells]] (intracellular), and as such contributes critically in numerous important ways to the optimal functioning of cells and therefore to optimal functioning of the organ systems and individuals they compose. Among other metabolic functions, potassium plays a role in the synthesis of proteins and in the biochemical transformations required for carbohydrate metabolism. | ||
Potassium plays an | Potassium plays an essential role in maintaining the electrical potential difference across the cell's plasma membrane, the intra- to extra-cellular electrical potential difference, typically referred to as the 'membrane potential'. That physiochemical regulatory function importantly enables normal transmission of information along nerves (nerve impulse transmission), normal contraction of muscle fibers, and normal functioning of the heart. The concentration of potassium inside cells (the intracellular fluid) exceeds that outside cells (the extracellular fluid) by an order of magnitude (~30 times), whereas the extracellular concentration of sodium exceeds that of its intracellular concentration by an order of magnitude (~10 times), the reverse of the situation with potassium. Those concentration differences between potassium ions and sodium ions generates the membrane potential, the inside potential negative with respect to the outside potential. A protein-based ion-pumping mechanism located within the lipid bilayer of the.... | ||
By influencing the electrical potential difference across the cell membrane, the ratio of the [[concentration]]s of potassium in intracellular fluid (ICF) to that in the cells' surrounding extracellular fluid (ECF) has important effects on the rate of transmission of electrical activity (pulses) along nerve fibers and skeletal muscle cells, which, among other things, affects the degree of contraction of the smooth muscles of arteries and arterioles (vascular tone).<ref name=moczydlowski2009>Moczydlowski EG. (2009) Electrophysiology of the Cell Membrane. In: Boron WF, Boulpaep EL (editors), Medical Physiology, 2nd ed. Saunders/Elsevier: Philadelphia. ISBN 9781416031154.</ref> Inasmuch as extracellular potassium varies in the 3-6 mmol/L range, while intracellular potassium concentrations average about 145 mmol/L, small changes in extracellular potassium concentration have a greater effect on the ICF-to-ECF potassium concentration ratio than similar small changes in intracellular potassium concentration. Subsequent sections discuss the implication of changes in the ICF-to-ECF potassium concentration ratio in human physiology. | By influencing the electrical potential difference across the cell membrane, the ratio of the [[concentration]]s of potassium in intracellular fluid (ICF) to that in the cells' surrounding extracellular fluid (ECF) has important effects on the rate of transmission of electrical activity (pulses) along nerve fibers and skeletal muscle cells, which, among other things, affects the degree of contraction of the smooth muscles of arteries and arterioles (vascular tone).<ref name=moczydlowski2009>Moczydlowski EG. (2009) Electrophysiology of the Cell Membrane. In: Boron WF, Boulpaep EL (editors), Medical Physiology, 2nd ed. Saunders/Elsevier: Philadelphia. ISBN 9781416031154.</ref> Inasmuch as extracellular potassium varies in the 3-6 mmol/L range, while intracellular potassium concentrations average about 145 mmol/L, small changes in extracellular potassium concentration have a greater effect on the ICF-to-ECF potassium concentration ratio than similar small changes in intracellular potassium concentration. Subsequent sections discuss the implication of changes in the ICF-to-ECF potassium concentration ratio in human physiology. | ||
In healthy persons whose daily consumption of potassium does not vary greatly, the amount of potassium consumed equals the amount excreted, by the kidney and gastrointestinal tract predominantly. Physiologists refer to that equality as ''zero'' net external body potassium balance. Of the major electrolytes, potassium has the highest ratio of potassium consumed to the amount of potassium in the extracellular compartment, a characteristic | In healthy persons whose daily consumption of potassium does not vary greatly, the amount of potassium consumed equals the amount excreted, by the kidney and gastrointestinal tract predominantly. Physiologists refer to that equality as ''zero'' net external body potassium balance. Of the major electrolytes, potassium has the highest ratio of potassium consumed to the amount of potassium in the extracellular compartment, a characteristic that presents a challenge in maintaining extracellular potassium concentrations within a set range in the face of variations in daily potassium intake, a challenge met by efficient excretion and somewhat less efficient conservation, mediated by homeostatic mechanisms not completely elucidated.<ref name=youn2009>Youn JH, McDonough AA. (2008) [http://dx.doi.org/10.1146/annurev.physiol.010908.163241 Recent Advances in Understanding Integrative Control of Potassium Homeostasis.] ''Annu.Rev Physiol'' 71:381-401. ISBN 18759636.</ref> | ||
Disturbances relating to body potassium deficiency may result from: | Disturbances relating to body potassium deficiency may result from: | ||
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Disturbances relating to body potassium excess may result from: | Disturbances relating to body potassium excess may result from: | ||
*drugs and kidney diseases that impair the kidney’s ability to excrete potassium in urine; | *drugs and kidney diseases that impair the kidney’s ability to excrete potassium in urine;<ref name=trimethoprim>Antoniou T, Gomes T, Juurlink DN, Loutfy MR, Glazier RH, Mamdani MM. (2010) [http://archinte.ama-assn.org/cgi/content/abstract/170/12/1045 Trimethoprim-Sulfamethoxazole-Induced Hyperkalemia in Patients Receiving Inhibitors of the Renin-Angiotensin System: A Population-Based Study]. ''Arch Intern Med'' 170:1045-9. | ||
*<font face="Gill Sans MT">Trimethoprim therapy can cause hyperkalemia and is often coprescribed with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). The objective of this study was to characterize the risk of hyperkalemia-associated hospitalization in elderly patients who were being treated with trimethoprim-sulfamethoxazole along with either an ACEI or an ARB...Compared with amoxicillin, the use of trimethoprim-sulfamethoxazole was associated with a nearly 7-fold increased risk of hyperkalemia-associated hospitalization (adjusted odds ratio, 6.7; 95% confidence interval, 4.5-10.0). No such risk was found with the use of comparator antibiotics. Conclusions: Among older patients treated with ACEIs or ARBs, the use of trimethoprim-sulfamethoxazole is associated with a major increase in the risk of hyperkalemia-associated hospitalization relative to other antibiotics. Alternate antibiotic therapy should be considered in these patients when clinically appropriate.</font></ref> | |||
*deficiency of hormones that act to promote kidney and gastrointestinal excretion of potassium. | *deficiency of hormones that act to promote kidney and gastrointestinal excretion of potassium. | ||
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==Requirements for potassium consumption by humans== | ==Requirements for potassium consumption by humans== | ||
Humans must habitually consume potassium because the body does not store it (as it does fat, say), while the kidney continues to excrete it in the [[urine]] even when potassium intake ceases. Potassium-rich foods include leafy green vegetables, vine fruits (e.g., squash, tomatoes, cucumbers, etc.), root vegetables, and tree fruits (see below). | |||
Humans must | |||
The Institute of Medicine of the National Academies of Science<ref name=ottendribook/> and its Food and Nutrition Board<ref name=napdri04/> recommend as "Adequate Intake" (AI)<ref>'''Note''':<br> | The Institute of Medicine of the National Academies of Science<ref name=ottendribook/> and its Food and Nutrition Board<ref name=napdri04/> recommend as "Adequate Intake" (AI)<ref>'''Note''':<br> | ||
:*The Food and Nutrition Board of the U.S. Institute of Medicine establishes values for “Adequate Intake” (AI) for nutrients when insufficient data precludes establishing a “Recommended Dietary Intake” (RDA) for that nutrient. It bases AI values how much of the nutrient a group (or groups) of apparently healthy people consume, as determined by observation or experiment. Determination of AI values requires judgments of state of health, in particular in reference to the nutrient’s health effects.</ref> of potassium, in mmol/day, as 77 and 97 for children ages 1-3 and 4-8 years, respectively, and as 115 and 120 for children 9-13 and 14-18 years, respectively. For adult men and women, ages 19 to >70 years, they recommend an AI of potassium as 120 mmol/day, and the same amount for pregnant women as young as 14 years, increasing to 130 mmol/day for lactating women. | :*The Food and Nutrition Board of the U.S. Institute of Medicine establishes values for “Adequate Intake” (AI) for nutrients when insufficient data precludes establishing a “Recommended Dietary Intake” (RDA) for that nutrient. It bases AI values how much of the nutrient a group (or groups) of apparently healthy people consume, as determined by observation or experiment. Determination of AI values requires judgments of state of health, in particular in reference to the nutrient’s health effects.</ref> of potassium, in mmol/day, as 77 and 97 for children ages 1-3 and 4-8 years, respectively, and as 115 and 120 for children 9-13 and 14-18 years, respectively. For adult men and women, ages 19 to >70 years, they recommend an AI of potassium as 120 mmol/day, and the same amount for pregnant women as young as 14 years, increasing to 130 mmol/day for lactating women. | ||
The | The Institute of Medicine of the National Academies of Science claims: | ||
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The AIs for potassium are based on a level of dietary intake that should maintain lower blood pressure levels, reduce the adverse effects of sodium chloride intake on blood pressure, reduce the risk of recurrent kidney stones, and possibly decrease bone loss.</font><ref name=ottendribook/> | |||
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The claim reflects concerns about inadequate potassium consumption as | The claim reflects concerns about inadequate potassium consumption as | ||
*contributing to hypertension (abnormally high arterial blood pressure) through its effects to constrict the small arteries (arterioles) that deliver blood to muscles and other organs, and to promote renal retention of sodium chloride); | *contributing to hypertension (abnormally high arterial blood pressure) through its effects to constrict the small arteries (arterioles) that deliver blood to muscles and other organs, and to promote renal retention of sodium chloride); | ||
*mitigating the effect of dietary sodium chloride ('salt') in contributing to hypertension, to kidney stone formation, and to osteoporosis (soft, fracture-prone bones). | *mitigating the effect of dietary sodium chloride ('salt') in contributing to hypertension, to kidney stone formation, and to osteoporosis (soft, fracture-prone bones). | ||
=== • Actual consumption of potassium by Americans, | === • Actual consumption of potassium by Americans, 2005 - 2010=== | ||
The U.S. Department of Agriculture released | The U.S. Department of Agriculture has released the results of the National Health and Nutrition Examination Survey (NHANES) data for 2005-2006, 2007-2008, and 2009-2010, giving the average values for the consumption of various nutrients, including potassium. <ref name=05-06K/><ref name=nhanesK2007-8>[http://www.ars.usda.gov/Services/docs.htm?docid=18349 What We Eat In America, NHANES 2007-2008]</ref><ref name=eatk2010/> The table below shows the average values for potassium consumption by Americans (2005-2010) with the recommended amounts given in the preceding section. | ||
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{| style="border-spacing:0;" | |||
| colspan="4" style="border:0.0139in solid #808080;padding:0.0194in;"| <center>'''Potassium Intake'''</center> | |||
<center>'''What We Eat in America'''</center> | |||
<center>'''2005-2006, 2007-2008, 2009-2010'''</center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Years'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Gender'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Potassium'''</center> | |||
<center>'''mmol/day'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''%'''</center> | |||
<center>'''Of'''</center> | |||
<center>'''Recom-'''</center> | |||
<center>'''mended'''</center> | |||
|- | |||
| colspan="4" style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''2005-2006'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Men'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''81'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''68'''</center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''2005-2006'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Women'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''61'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''50'''</center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center> </center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center> </center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center> </center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center> </center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''2007-2008'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Men'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''78'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''65'''</center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''2007-2008'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Women'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''58'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''50'''</center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center> </center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center> </center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center> </center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center> </center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''2009-2010'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Men'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''81'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''68'''</center> | |||
|- | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''2009-2010'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''Women'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:none;padding:0.0194in;"| <center>'''61'''</center> | |||
| style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center>'''50'''</center> | |||
|- | |||
| colspan="4" style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| | |||
|- | |||
| colspan="4" style="border-top:none;border-bottom:0.0139in solid #808080;border-left:0.0139in solid#808080;border-right:0.0139in solid #808080;padding:0.0194in;"| <center><font face="Gill Sans MT">Recommended “Adequate Intake”, 120 mmol/day, identical for men and women, and therefore not adjusted for differences in body size or lean body mass between men and women.</font></center> | |||
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<center><font face="Gill Sans MT"> Because the Food and Nutrition Board indicated that eating ordinary foods imposed no danger of consuming excess potassium except in certain potassium non-tolerant conditions, most Americans could likely achieve “adequate intakes” or more, by doubling their potassium intake.</font></center> | |||
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Note that average consumption of potassium by adults falls well below recommended amounts, with American women consuming half the recommended amount on average, and American men about two-thirds. Those findings do not indicate improvement in achieving "adequate intakes" over the findings reported for years 2003-2004.<ref name=03-04K/> <ref name=kimmons2009>Kimmons J. Gillespie C, Seymour J, Serdula M, Blanck HM. (2009) Fruit and Vegetable Intake Among Adolescents and Adults in the United States: Percentage: Meeting Individualized Recommendations. ''Medscape J. Med.'' 11(1):26. [http://www.medscape.com/viewarticle/586492 Full Text]. | Note that average consumption of potassium by adults falls well below recommended amounts, with American women consuming half the recommended amount on average, and American men about two-thirds. Those findings do not indicate improvement in achieving "adequate intakes" over the findings reported for years 2003-2004.<ref name=03-04K/> <ref name=kimmons2009>Kimmons J. Gillespie C, Seymour J, Serdula M, Blanck HM. (2009) Fruit and Vegetable Intake Among Adolescents and Adults in the United States: Percentage: Meeting Individualized Recommendations. ''Medscape J. Med.'' 11(1):26. [http://www.medscape.com/viewarticle/586492 Full Text]. | ||
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Children and adolescents showed a similar range of insufficiencies of potassium consumption in the two reports. <ref name=03-04K/> <ref name=05-06K/> | Children and adolescents showed a similar range of insufficiencies of potassium consumption in the two reports. <ref name=03-04K/> <ref name=05-06K/> | ||
More recent analyses find that most Americans under-consume vegetables and fruit, the richest food sources of potassium.<ref name=guenther2006>Guenther PM, Dodd KW, Reedy J, Krebs-Smith SM. (2006) [http://dx.doi.org/10.1016/j.jada.2006.06.002 Most Americans eat much less than recommended amounts of fruits and vegetables]. ''Journal of the American Dietetic Association'' 106(9):1371-9.</ref> <ref name=krebssmith2010>Krebs-Smith SM, Guenther, Subar AF, Kirkpatrick SI, Dodd KW. (2010) [http://doi.dx.org/10.3945/n.110.124826 Americans Do Not Meet Federal Dietary Recommendations]. ''J. Nutr.'' 140: 1832–1838. | |||
:*<font face="Gill Sans MT">"This analysis indicates that nearly the entire U.S. population consumes a diet with fewer vegetables and whole grains than recommended and that a large majority underconsume fruits, milk, and oils relative to recommendations. Young adults have the greatest tendency toward insufficient intakes, although no sex-age group is immune."</font></ref> | |||
Without increasing total energy (calorie) intake, Americans could increase potassium consumption to achieve "adequate intake" by reducing intake of potassium-poor foods and increasing intake of potassium-rich foods. | Without increasing total energy (calorie) intake, Americans could increase potassium consumption to achieve "adequate intake" by reducing intake of potassium-poor foods and increasing intake of potassium-rich foods. | ||
== Potassium | == Potassium content of foods: Related to alkali (base) content == | ||
Understanding the biological effects of dietary potassium ions (cations) requires an associated understanding of the nature of the negatively charged ions (anions) that accompany potassium in foods, balancing potassium’s positive charge, thus maintaining electroneutrality. In natural diets not subjected to commercial processing that includes addition of potassium salts—typically potassium chloride—a variety of organic anions (e.g., citrate, fumarate) accompany the potassium ions in foods, in amounts sufficient to nearly balance the positive charge of the potassium ions (i.e., in near [[chemical equivalent]] amounts). Following their absorption by the gastrointestinal tract, the body converts a large fraction of those organic anions to bicarbonate (an acid-neutralizing substance, or base), as an end-product of metabolism.<ref>'''''Note:''''' If one consumes citric acid, for example, the body metabolizes it to carbon dioxide and water. If it consumes potassium citrate, it metabolizes it to potassium bicarbonate.</ref> Thus, diets with differing amounts of potassium exert potassium-induced biological effects associated and often interacting with the effects of the differing amounts of acid-neutralizing base, bicarbonate, as generated by the body from the potassium-accompanying organic anions. Physiologists often cannot dissect out the specific effects of the co-ions potassium and bicarbonate, when, for example, a person increases their dietary intake of potassium-rich foods, which typically contain bicarbonate-generating organic anions in abundance (see Table 1 and accompanying text). | Understanding the biological effects of dietary potassium ions (cations) requires an associated understanding of the nature of the negatively charged ions (anions) that accompany potassium in foods, balancing potassium’s positive charge, thus maintaining electroneutrality. In natural diets not subjected to commercial processing that includes addition of potassium salts—typically potassium chloride—a variety of organic anions (e.g., citrate, fumarate) accompany the potassium ions in foods, in amounts sufficient to nearly balance the positive charge of the potassium ions (i.e., in near [[chemical equivalent]] amounts). Following their absorption by the gastrointestinal tract, the body converts a large fraction of those organic anions to bicarbonate (an acid-neutralizing substance, or base), as an end-product of metabolism.<ref>'''''Note:''''' If one consumes citric acid, for example, the body metabolizes it to carbon dioxide and water. If it consumes potassium citrate, it metabolizes it to potassium bicarbonate.</ref> Thus, diets with differing amounts of potassium exert potassium-induced biological effects associated and often interacting with the effects of the differing amounts of acid-neutralizing base, bicarbonate, as generated by the body from the potassium-accompanying organic anions. Physiologists often cannot dissect out the specific effects of the co-ions potassium and bicarbonate, when, for example, a person increases their dietary intake of potassium-rich foods, which typically contain bicarbonate-generating organic anions in abundance (see Table 1 and accompanying text). | ||
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The following foods supply 1.9 to 3.1 mmol potassium per 100 kcal portion: brown rice, wheat, whole-grain wheat flour, corn, and barley. The following foods supply 8.8 to 61 mmol potassium per 100 kcal portion: oranges, bananas, carrots, squash, and spinach. On average, substituting the latter for the former foods can increase potassium intake approximately tenfold. | |||
[...in progress...] | [...in progress...] | ||
==The | ==The paleolithic perspective on the 'optimal' dietary requirement of humans== | ||
.... | According to the 'paleolithic paradigm' as applicable to nutritional science, the types of foods we eat today differ in important health-related ways from those eaten for millions of years as our genus, ''Homo'', evolved from earlier bipedal species, and from those eaten for millions of years as our species, ''Homo sapiens'', evolved and survived. Until agriculture and animal husbandry emerged about 10,000 years ago and became the dominant source of the human food supply about 7,000 years ago, ''Homo'' and its lineal ancestors subsisted solely on foods hunted and gathered from a pre-civilization wilderness. Having adapted their anatomy, physiology and metabolism to wild plant and animal foods through natural selection and other evolutionary forces operating over millions of years, enabling survival of the lineage culminating in a world spanning humanity of pre-agricultural ''Homo sapiens'', they then drastically changed the types of foods that they habitually consumed, and continued to make major changes, consuming cultivated cereal grains, milk from domesticated animals, and other unfamiliar 'foods', products of the industrial revolution, the fast-food revolution, agribusiness, and grain fed fatty animals. | ||
The nutrient profile of the average ''Homo sapien'' would shows little resemblance to that of the average pre-agricultural ''Homo sapien''. That dissimilarity would extend to the amount of nearly every type of chemical species consumed. | |||
== Potassium deficiency in type 2 diabetes mellitus and in the metabolic syndrome == | == Potassium deficiency in type 2 diabetes mellitus and in the metabolic syndrome == | ||
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Research has not determined optimal potassium intake ranges for maximal protection against heart disease and stroke and other detrimental effects of hypertension. | Research has not determined optimal potassium intake ranges for maximal protection against heart disease and stroke and other detrimental effects of hypertension. | ||
== Dietary | Because high sodium intake has also been implicated in the pathogenesis of hypertension and cardiovascular disease (CVD), investigators have considered the possibility that the relative amounts of sodium and potassium in the diet might be important. The '' Trials of Hypertension Prevention Collaborative Research Group'' report that in people with borderline or pre-hypertension, a higher ratio of sodium-to-potassium, estimated from 24-hour urinary excretion rates of the two ions, better estimates the risk of CVD than the intake of either considered separately: <ref name=cook2009>Cook NR, Obarzanek E, Cutler JA, Buring JE, Rexrode KM, Kumanyika SK, Appel LJ, Whelton PK. (2009) [http://dx.doi.org/ 10.1001/archinternmed.2008.5234:36 PM4:36 PM Joint Effects of Sodium and Potassium Intake on Subsequent Cardiovascular Disease]. ''Arch Intern Med.'' 169(1):32-40.</ref> | ||
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<font face="Gill Sans MT">In observational analyses of the mean urinary excretion during 1-1½ to 3 years, we found a suggested positive relationship of urinary sodium excretion and a suggested inverse relationship of urinary potassium excretion with risk of CVD, but neither was statistically significant when considered separately. Both measures strengthened when modeled jointly, with opposite but similar effects on risk. However, the sodium to potassium excretion ratio displayed the strongest and statistically significant association, with a 24% increase in risk per unit of the ratio that was similar for CHD [coronary heart disease] and stroke and was consistent across subgroups.</font> <ref name=cook2009/> | |||
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<!--Incorporate info from: Chang 2006 ajcn - Effect of potassium-enriched salt on cardiovascular mortality(e:\dat\potasium in...--> | |||
== Dietary Potassium and Risk of Osteoporosis == | |||
... | |||
Buehlmeier and colleagues found, in otherwise healthy men consuming a high sodium chloride diet, a condition associated with low-grade systemic metabolic acidosis, that administration of 90 mmol of potassium bicarbonate mitigated the acidosis, reduced apparent levels of active glucocorticoids, and reduced biomarkers of bone resorption along with reduced urinary excretion of calcium. <ref name=buehlmeier2012>Buehlmeier J, Frings-Meuthen P, Remer T, Maser-Gluth C, Stehle P, Biolo G, Heer M. (2012) [http://dx.doi.org/10.1210/jc.2012-2857 Alkaline Salts to Counteract Bone Resorption and Protein Wasting Induced by High Salt Intake: Results of a Randomized Controlled Trial]. ''The Journal of Clinical Endocrinology & Metabolism''. Published online before print October 1, 2012. | |||
*<font face="Gill Sans MT">There was a trend of declining net protein catabolism when high NaCl was combined with KHCO3 (P = 0.052).</font></ref> | |||
[...in progress...] | [...in progress...] | ||
Dawson-Hughes<ref name=dawson2008>Bess Dawson-Hughes1, Susan S. Harris1, Nancy J. Palermo1, Carmen | |||
Castaneda-Sceppa2, Helen M. Rasmussen1, and Gerard E. Dallal. (2009) [http://jcem.endojournals.org/content/94/1/96.full Treatment with Potassium Bicarbonate Lowers Calcium Excretion and Bone Resorption in Older Men and Women]. ''J Endocrin Metabolism'' 94(1):96-102.</ref> | |||
===References above heading=== | |||
{{reflist|2}} | |||
==Dietary potassium deficiency and skeletal muscle wasting== | |||
Skeletal muscle potassium content accounts for >90% of the body's total potassium. As skeletal muscle function requires adequate potassium for efficient neural initiation of muscle contraction, as efficient execution of muscle contractions requires adequate potassium, not surprisingly dietary potassium insufficiency leads to relative muscle weakness and consequent disuse muscle mass reduction. Physiologists have not determined the shape of the curve that relates muscle function, or muscle mass, to dietary potassium intake over the large range consumed by Americans studied in a controlled setting. Possibly contributing, other components present or absent in the different types of foods consumed in generating that large range of potassium intakes play a role in determining the shape of the curve. Whether at current levels of foodpotassium | |||
The molecular mechanisms | |||
== Dietary Potassium and Risk of Kidney Stones == | == Dietary Potassium and Risk of Kidney Stones == | ||
[...in progress...] | [...in progress...] | ||
Latest revision as of 21:20, 1 January 2014
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To maintain life and health, the diet of humans must contain the chemical element, potassium, in its ionic form (K+), usually consumed as potassium salts of organic acids in food (e.g., potassium citrate), found most abundantly in non-grain plant foods (vegetables and fruits).
In 2004-2006, and again in 2010, the Institute of Medicine of the National Academies of Science [1] and its Food and Nutrition Board [2] [3] recommended that adult humans consume 4700 milligrams (mg) of potassium per day, or more, which, calculated from the atomic mass of potassium (39.1 mg per mmol), corresponds to 120 millimoles (mmol) potassium per day: 4700 mg/39.1 mg/mmol=120 mmol. That recommended intake of potassium substantially exceeds estimates from recent surveys of average intakes by the general population, raising the possibility that a persisting state of suboptimal body potassium content, and rate of the body throughput of potassium, prevails in the general population. [4] [5] [6] Underconsumption of potassium reflects the general American dietary crisis of under-consumption of healthful nutrients and over-consumption of unhealthful nutrients and nutrient-empty calories.[7]
Subsequent sections will discuss potassium intake recommendations for children and special groups, as well as more recent perspectives on the 'optimal' requirements for dietary potassium in humans.
General considerations
Potassium ranks as the most abundant cation (positive ion) inside animal cells (intracellular), and as such contributes critically in numerous important ways to the optimal functioning of cells and therefore to optimal functioning of the organ systems and individuals they compose. Among other metabolic functions, potassium plays a role in the synthesis of proteins and in the biochemical transformations required for carbohydrate metabolism.
Potassium plays an essential role in maintaining the electrical potential difference across the cell's plasma membrane, the intra- to extra-cellular electrical potential difference, typically referred to as the 'membrane potential'. That physiochemical regulatory function importantly enables normal transmission of information along nerves (nerve impulse transmission), normal contraction of muscle fibers, and normal functioning of the heart. The concentration of potassium inside cells (the intracellular fluid) exceeds that outside cells (the extracellular fluid) by an order of magnitude (~30 times), whereas the extracellular concentration of sodium exceeds that of its intracellular concentration by an order of magnitude (~10 times), the reverse of the situation with potassium. Those concentration differences between potassium ions and sodium ions generates the membrane potential, the inside potential negative with respect to the outside potential. A protein-based ion-pumping mechanism located within the lipid bilayer of the....
By influencing the electrical potential difference across the cell membrane, the ratio of the concentrations of potassium in intracellular fluid (ICF) to that in the cells' surrounding extracellular fluid (ECF) has important effects on the rate of transmission of electrical activity (pulses) along nerve fibers and skeletal muscle cells, which, among other things, affects the degree of contraction of the smooth muscles of arteries and arterioles (vascular tone).[8] Inasmuch as extracellular potassium varies in the 3-6 mmol/L range, while intracellular potassium concentrations average about 145 mmol/L, small changes in extracellular potassium concentration have a greater effect on the ICF-to-ECF potassium concentration ratio than similar small changes in intracellular potassium concentration. Subsequent sections discuss the implication of changes in the ICF-to-ECF potassium concentration ratio in human physiology.
In healthy persons whose daily consumption of potassium does not vary greatly, the amount of potassium consumed equals the amount excreted, by the kidney and gastrointestinal tract predominantly. Physiologists refer to that equality as zero net external body potassium balance. Of the major electrolytes, potassium has the highest ratio of potassium consumed to the amount of potassium in the extracellular compartment, a characteristic that presents a challenge in maintaining extracellular potassium concentrations within a set range in the face of variations in daily potassium intake, a challenge met by efficient excretion and somewhat less efficient conservation, mediated by homeostatic mechanisms not completely elucidated.[9]
Disturbances relating to body potassium deficiency may result from:
- prolonged inadequate consumption of potassium-containing foods;
- inappropriately large rates of excretion of potassium in urine;
- inappropriately large excretion rates of potassium in feces.
Disturbances relating to body potassium excess may result from:
- drugs and kidney diseases that impair the kidney’s ability to excrete potassium in urine;[10]
- deficiency of hormones that act to promote kidney and gastrointestinal excretion of potassium.
Subsequent sections will elaborate on the above concepts.
Requirements for potassium consumption by humans
Humans must habitually consume potassium because the body does not store it (as it does fat, say), while the kidney continues to excrete it in the urine even when potassium intake ceases. Potassium-rich foods include leafy green vegetables, vine fruits (e.g., squash, tomatoes, cucumbers, etc.), root vegetables, and tree fruits (see below).
The Institute of Medicine of the National Academies of Science[1] and its Food and Nutrition Board[2] recommend as "Adequate Intake" (AI)[11] of potassium, in mmol/day, as 77 and 97 for children ages 1-3 and 4-8 years, respectively, and as 115 and 120 for children 9-13 and 14-18 years, respectively. For adult men and women, ages 19 to >70 years, they recommend an AI of potassium as 120 mmol/day, and the same amount for pregnant women as young as 14 years, increasing to 130 mmol/day for lactating women.
The Institute of Medicine of the National Academies of Science claims:
The AIs for potassium are based on a level of dietary intake that should maintain lower blood pressure levels, reduce the adverse effects of sodium chloride intake on blood pressure, reduce the risk of recurrent kidney stones, and possibly decrease bone loss.[1] |
The claim reflects concerns about inadequate potassium consumption as
- contributing to hypertension (abnormally high arterial blood pressure) through its effects to constrict the small arteries (arterioles) that deliver blood to muscles and other organs, and to promote renal retention of sodium chloride);
- mitigating the effect of dietary sodium chloride ('salt') in contributing to hypertension, to kidney stone formation, and to osteoporosis (soft, fracture-prone bones).
• Actual consumption of potassium by Americans, 2005 - 2010
The U.S. Department of Agriculture has released the results of the National Health and Nutrition Examination Survey (NHANES) data for 2005-2006, 2007-2008, and 2009-2010, giving the average values for the consumption of various nutrients, including potassium. [5][12][6] The table below shows the average values for potassium consumption by Americans (2005-2010) with the recommended amounts given in the preceding section.
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Note that average consumption of potassium by adults falls well below recommended amounts, with American women consuming half the recommended amount on average, and American men about two-thirds. Those findings do not indicate improvement in achieving "adequate intakes" over the findings reported for years 2003-2004.[4] [13]
Children and adolescents showed a similar range of insufficiencies of potassium consumption in the two reports. [4] [5]
More recent analyses find that most Americans under-consume vegetables and fruit, the richest food sources of potassium.[14] [15]
Without increasing total energy (calorie) intake, Americans could increase potassium consumption to achieve "adequate intake" by reducing intake of potassium-poor foods and increasing intake of potassium-rich foods.
Potassium content of foods: Related to alkali (base) content
Understanding the biological effects of dietary potassium ions (cations) requires an associated understanding of the nature of the negatively charged ions (anions) that accompany potassium in foods, balancing potassium’s positive charge, thus maintaining electroneutrality. In natural diets not subjected to commercial processing that includes addition of potassium salts—typically potassium chloride—a variety of organic anions (e.g., citrate, fumarate) accompany the potassium ions in foods, in amounts sufficient to nearly balance the positive charge of the potassium ions (i.e., in near chemical equivalent amounts). Following their absorption by the gastrointestinal tract, the body converts a large fraction of those organic anions to bicarbonate (an acid-neutralizing substance, or base), as an end-product of metabolism.[16] Thus, diets with differing amounts of potassium exert potassium-induced biological effects associated and often interacting with the effects of the differing amounts of acid-neutralizing base, bicarbonate, as generated by the body from the potassium-accompanying organic anions. Physiologists often cannot dissect out the specific effects of the co-ions potassium and bicarbonate, when, for example, a person increases their dietary intake of potassium-rich foods, which typically contain bicarbonate-generating organic anions in abundance (see Table 1 and accompanying text).
Table 1 shows the potassium content of the major food groups, indicating the relation of potassium content to the net acid (or bicarbonate) load supplied to the body by each food group (see comments following table). [NB: Because potassium ions have a single charge (univalent), 1 millimole (mmol) of potassium equals 1 milliequivalent (meq) of potassium.]
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In Table 1, positive (+) and negative (–) values of net acid load represent acid-producing and bicarbonate-producing equivalents, respectively, in the units specified. Values of net acid load: calculated first for individual food items then averaged per food group, as per compositional values in:[17]. Acid load calculations: as described in:[18] Note that net acid-producing foods tend to have much higher ratios of protein-to-potassium than do net bicarbonate-producing foods (regression of net acid load against Protein/Potassium, r=0.48, p=0.05). Note the relatively low values of protein and potassium in the cereal grain group, of which whole grains comprised six of the seven items in the group.
Table 1 reveals a number of important aspects of food potassium:
- Per unit energy content (kilocalories, abbrev: kcal), non-cereal-grain plant foods provide the most abundant source of potassium.
- The top five plant-food sources of potassium (meq/kcal): root vegetables (celeriac, rutabaga, turnips, carrots, parsnips, sweet potato, potato, yams, onions); vegetable fruit (aka vine fruit) (tomatoes, zucchini, eggplant, cucumbers); leafy greens (spinach, lettuce, kale, chard); stalks (celery, broccoli stalks); mushrooms (not strictly a plant).
- The food sources richest in potassium also supply bicarbonate to the body, as indicated by negative values of "net acid load".
- The potassium content in acid-producing foods (animal-source foods and cereal grains) average about one-fifth that of plant-source foods, which do not contain sufficient quantities of bicarbonate-generating organic anions to neutralize the acid generated from protein and other sustances they contain.
- The ratio of protein-to-potassium in plant-source foods falls short of animal-source foods by a factor of 10.
- Legumes provide moderate amounts of potassium with little or no acid or bicarbonate load.
Table 2 lists selected food sources of potassium, showing amounts of potassium for standard portions, in descending order of amount of potassium per 100 kilocalorie of food source. Raw data for the calculations: taken from [19]
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The following foods supply 1.9 to 3.1 mmol potassium per 100 kcal portion: brown rice, wheat, whole-grain wheat flour, corn, and barley. The following foods supply 8.8 to 61 mmol potassium per 100 kcal portion: oranges, bananas, carrots, squash, and spinach. On average, substituting the latter for the former foods can increase potassium intake approximately tenfold.
[...in progress...]
The paleolithic perspective on the 'optimal' dietary requirement of humans
According to the 'paleolithic paradigm' as applicable to nutritional science, the types of foods we eat today differ in important health-related ways from those eaten for millions of years as our genus, Homo, evolved from earlier bipedal species, and from those eaten for millions of years as our species, Homo sapiens, evolved and survived. Until agriculture and animal husbandry emerged about 10,000 years ago and became the dominant source of the human food supply about 7,000 years ago, Homo and its lineal ancestors subsisted solely on foods hunted and gathered from a pre-civilization wilderness. Having adapted their anatomy, physiology and metabolism to wild plant and animal foods through natural selection and other evolutionary forces operating over millions of years, enabling survival of the lineage culminating in a world spanning humanity of pre-agricultural Homo sapiens, they then drastically changed the types of foods that they habitually consumed, and continued to make major changes, consuming cultivated cereal grains, milk from domesticated animals, and other unfamiliar 'foods', products of the industrial revolution, the fast-food revolution, agribusiness, and grain fed fatty animals.
The nutrient profile of the average Homo sapien would shows little resemblance to that of the average pre-agricultural Homo sapien. That dissimilarity would extend to the amount of nearly every type of chemical species consumed.
Potassium deficiency in type 2 diabetes mellitus and in the metabolic syndrome
Potassium deficiency — or at least suboptimal body content of potassium — may play an important role in causing, sustaining or aggravating type 2 diabetes mellitus and/or metabolic syndrome.
The metabolic syndrome, a serious disturbance of body metabolism and physiology, consists of resistance of certain cell types of the body (e.g., fat cells, skeletal muscle cells) to the ability of the hormone insulin to promote cellular entry of the energy-rich molecule, glucose. Patients with the syndrome may show the following abnormalities: high blood pressure (or use of drugs to control hypertension); high levels of serum triglycerides; low levels of high-density lipoprotein (HDL) cholesterol; overweight, in particular visceral obesity (obesity manifested by abnormally increased abdominal girth); and, detectable levels of the protein, albumin, in the urine (microalbuminuria). The abnormalities of triglyceride levels typically associate with other blood fat disturbances (dyslipidemia) that foster atherosclerosis (buildup of plaques in artery walls that predispose to reduced blood flow to vital organs (e.g., the heart) and to formation of blood clots that can break off and plug vital vessels to the brain, causing stroke). The biochemical factors that promote clot formation are also stimulated in the metabolic syndrome, and the syndrome appears to be one of a chronic state of inflammation, the typical body response to tissue injury. Overweight and obese children show a strong correlation between biochemical markers of inflammation and the metabolic syndrome and insulin resistance, suggesting early-in-life involvement of inflammation related to overweight.[20]
An etimated 50 million Americans have the metabolic syndrome.[21]
Studies in humans using a technique called nuclear magnetic resonance spectroscopy found cellular potassium deficiency in patients with type 2 diabetes mellitus and in patients with hypertension.[22][23] The use of such a state-of-the-art technique enabled discovery of intracellular potassium deficiency not likely expected from routine clinical tests.
In addition, the studies indicated more acidity in the cells of patients with hypertension, especially those also having diabetes.[23]
A longitudinal study of nearly two thousand men and women in Finland (ages 35-64 years) found no evidence of an association of potassium intake (indexed as 24-hour urinary potassium excretion) and the incidence of type 2 diabetes.[24] Higher sodium chloride intakes did predict the incidence of type 2 diabetes among the subjects. Yet, from the study data reported, one cannot tell if the authors performed the same type of data analysis for potassium as they did for sodium, nor did they examine whether the ratio of sodium-to-potassium had a stronger association with diabetes incidence than did sodium alone. If the latter, that might suggest that higher potassium intakes, to lower the sodium-to-potassium ratio, might mitigate or eliminate the association with diabetes incidence.
Another studied showed that a dietary pattern emphasizing fruit (a potassium-rich food), and deemphasizing foods not especially rich in potassium, reduced the risk of type 2 diabetes.[25]
Studies of close to 500 women (teachers) in Iran showed that increasing intake of fruits and vegetables — potassium-and alkali-rich foods — proportionately decreased the chances of the participants having metabolic syndrome, by 30-35%.[26] The investigators also found that higher fruit and vegetable intakes associated with lower levels of a conventional biomarker of inflammation, a common concomitant of the metabolic syndrome.
Patients with the adrenal gland disorder, primary aldosteronism, have excessively high levels of aldosterone, a hormone that acts on the kidney to cause it to retain sodium and waste body potassium in the urine. They have low levels of the fat-cell-secreting hormone, adiponectin, resulting in insulin resistance. The patients commonly have the metabolic syndrome. Among patients with the metabolic syndrome, the lower their potassium levels the lower their adiponectin levels and the greater their insulin resistance. Though only a study of correlation, the study provides further suspicion that potassium deficiency may play a role in the pathogenesis of the metabolic syndrome.[27]
• Clinical identification of the metabolic syndrome
- From: Source: National Cholesterol Education Program, Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III), National Heart, Lung, and Blood Institute, National Institutes of Health, May 2001, [28] and the Grundy Report in 2004. [29]
- See Table 1, page 435 of Grundy et al.[29]
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Potassium Intake, Blood Pressure Regulation, and Risk of Heart Disease and Stroke
Intervention-type research in humans has found that raising potassium intakes reduces blood pressure in the arteries (arterial hypertension).[30] [31] In both the population at large and in people with “high blood pressure” (aka “hypertension”), increasing potassium intake by 30-60 meq/day within the range of low (e.g., 30 meq/day) to high (e.g., 200 meq/day) intakes——either from food or prescribed supplements——tends to lower blood pressure.[32] The degree of blood pressure-lowering depends on a variety of factors, including amount of increase in potassium intake and ancestry.
Because people with higher blood pressures have greater risks of death from heart disease (e.g., heart attacks) and stroke (blockage or leakage of blood vessel in the brain),[33] dietary potassium’s effect in helping keep blood pressures lower in part justified setting the recommended intake of potassium at 120 meq/day---substantially higher than the population average---for American adults by the Institute of Medicine in 2005.[1]
These correspondences in part helped justify the Institute of Medicine’s recommendation to American adults to increase their intake of potassium to 120 meq/day:
The IOM makes no statement whether 120 meq/day potassium intake ‘’optimizes’’ cardiovascular health, but it sets no upper limit restrictions on potassium intake from food, which could reach 200-300 meq/day. Diets that potassium-rich include diets emphasizing the available abundant variety of potassium-rich vegetables and fruits, and deemphasizing fatty animal-source foods (like fatty hamburger meat) and high-fat-or-high-refined-carbohydrate foods with little-or-no additional nutrient content (like vegetable oil or pancake syrup)—diets considered health-fostering in many ways besides mitigating high blood pressure tissue injury.
Research has not determined optimal potassium intake ranges for maximal protection against heart disease and stroke and other detrimental effects of hypertension.
Because high sodium intake has also been implicated in the pathogenesis of hypertension and cardiovascular disease (CVD), investigators have considered the possibility that the relative amounts of sodium and potassium in the diet might be important. The Trials of Hypertension Prevention Collaborative Research Group report that in people with borderline or pre-hypertension, a higher ratio of sodium-to-potassium, estimated from 24-hour urinary excretion rates of the two ions, better estimates the risk of CVD than the intake of either considered separately: [38]
In observational analyses of the mean urinary excretion during 1-1½ to 3 years, we found a suggested positive relationship of urinary sodium excretion and a suggested inverse relationship of urinary potassium excretion with risk of CVD, but neither was statistically significant when considered separately. Both measures strengthened when modeled jointly, with opposite but similar effects on risk. However, the sodium to potassium excretion ratio displayed the strongest and statistically significant association, with a 24% increase in risk per unit of the ratio that was similar for CHD [coronary heart disease] and stroke and was consistent across subgroups. [38] |
Dietary Potassium and Risk of Osteoporosis
...
Buehlmeier and colleagues found, in otherwise healthy men consuming a high sodium chloride diet, a condition associated with low-grade systemic metabolic acidosis, that administration of 90 mmol of potassium bicarbonate mitigated the acidosis, reduced apparent levels of active glucocorticoids, and reduced biomarkers of bone resorption along with reduced urinary excretion of calcium. [39]
[...in progress...] Dawson-Hughes[40]
References above heading
- ↑ 1.0 1.1 1.2 1.3 Otten JJ, Hellwig JP, Meyers LD (editors) (2006) Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. National Academies Press. Pages 370-379. ISBN 0-309-65646-X
- ↑ 2.0 2.1 Panel on Dietary Reference Intakes for Electrolytes and Water. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Food and Nutrition Board. Institute of Medicine of The National Academies (2004) Dietary Reference Intakes For Water, Potassium, Sodium, Chloride, and Sulfate “Potassium” pp. 186-268. The National Academies Press, Washington, D.C.
- ↑ Dietary Guidelines for Americans, 2010. PDF (p40. U.S Department of Agriculture. U.S. Department of Health and Human Services.
- ↑ 4.0 4.1 4.2 What We Eat in America, NHANES 2003-2004, Tables. 1. Nutrient Intakes: Mean Amounts Consumed per Individual, One Day, 2003-2004 (Downloadable PDF File)
- ↑ 5.0 5.1 5.2 Nutrient Intakes: Mean Amounts Consumed per Individual, One Day, 2005-2006. U.S. Department of Agriculture, Agricultural Research Services, Fast Facts, Reports/Articles, and Tables (2005-2006).
- ↑ 6.0 6.1 What We Eat in America, 2009-2010. USDA. Downloadable pdf Tables.
- ↑ Krebs-Smith SM, Guenther PM, Subar AF, Kirkpatrick SI, & Dodd KW (2010) Americans do not meet federal dietary recommendations. J Nutr 140(10):1832-1838. PMID 2937576.
- ↑ Moczydlowski EG. (2009) Electrophysiology of the Cell Membrane. In: Boron WF, Boulpaep EL (editors), Medical Physiology, 2nd ed. Saunders/Elsevier: Philadelphia. ISBN 9781416031154.
- ↑ Youn JH, McDonough AA. (2008) Recent Advances in Understanding Integrative Control of Potassium Homeostasis. Annu.Rev Physiol 71:381-401. ISBN 18759636.
- ↑ Antoniou T, Gomes T, Juurlink DN, Loutfy MR, Glazier RH, Mamdani MM. (2010) Trimethoprim-Sulfamethoxazole-Induced Hyperkalemia in Patients Receiving Inhibitors of the Renin-Angiotensin System: A Population-Based Study. Arch Intern Med 170:1045-9.
- Trimethoprim therapy can cause hyperkalemia and is often coprescribed with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). The objective of this study was to characterize the risk of hyperkalemia-associated hospitalization in elderly patients who were being treated with trimethoprim-sulfamethoxazole along with either an ACEI or an ARB...Compared with amoxicillin, the use of trimethoprim-sulfamethoxazole was associated with a nearly 7-fold increased risk of hyperkalemia-associated hospitalization (adjusted odds ratio, 6.7; 95% confidence interval, 4.5-10.0). No such risk was found with the use of comparator antibiotics. Conclusions: Among older patients treated with ACEIs or ARBs, the use of trimethoprim-sulfamethoxazole is associated with a major increase in the risk of hyperkalemia-associated hospitalization relative to other antibiotics. Alternate antibiotic therapy should be considered in these patients when clinically appropriate.
- ↑ Note:
- The Food and Nutrition Board of the U.S. Institute of Medicine establishes values for “Adequate Intake” (AI) for nutrients when insufficient data precludes establishing a “Recommended Dietary Intake” (RDA) for that nutrient. It bases AI values how much of the nutrient a group (or groups) of apparently healthy people consume, as determined by observation or experiment. Determination of AI values requires judgments of state of health, in particular in reference to the nutrient’s health effects.
- ↑ What We Eat In America, NHANES 2007-2008
- ↑ Kimmons J. Gillespie C, Seymour J, Serdula M, Blanck HM. (2009) Fruit and Vegetable Intake Among Adolescents and Adults in the United States: Percentage: Meeting Individualized Recommendations. Medscape J. Med. 11(1):26. Full Text.
- Abstract: Context: Fruit and vegetable intake is an important part of a healthy diet and is associated with numerous positive health outcomes. MyPyramid provides recommendations for fruit and vegetable consumption based on individual calorie requirements as determined by an individual's age, sex, and physical activity level. Objectives: To determine (1) median fruit and vegetable consumption from all dietary sources among adolescent and adult consumers and the percentage of adolescents and adults meeting individual recommended intake levels based on caloric requirements and (2) consumption levels among various demographic groups, intake levels from subtypes of fruits and vegetables, and primary contributors to fruit and vegetable intake. Design: Analysis of 2-day, 24-hour recall data from the 2003-2004 National Health and Nutrition Examination Survey (NHANES), a continuous, nationally representative, cross-sectional survey. Results: This study included dietary contributions of fruits and vegetables from all dietary sources. Fewer than 1 in 10 Americans meet their calorie-specific MyPyramid fruit or vegetable recommendations. Higher intake was not observed in subgroups with higher recommendations for fruit and vegetable consumption based on caloric requirements. The primary contributors to total fruit intake were whole fruits among adults and fruit juices among adolescents. The largest single contributor to overall fruit intake was orange juice. Potatoes dominated vegetable consumption, particularly among adolescents, in whom fried potatoes increased the median vegetable intake from 0.72 cup to 1.21 cups per day. Dark green and orange vegetables and legumes accounted for a small portion of vegetable intake, and few people met the recommendations. Conclusions: Few American adolescents or adults reported consuming the recommended amounts of fruits or vegetables. Increasing consumption will probably require multifaceted approaches that augment educational campaigns with policy and environmental strategies aimed at the food system at large, from farm to plate, including schools, worksites, and retail establishments. Increasing America's fruit and vegetable consumption is an important public health strategy for weight management and reduction of risk for chronic disease.
- ↑ Guenther PM, Dodd KW, Reedy J, Krebs-Smith SM. (2006) Most Americans eat much less than recommended amounts of fruits and vegetables. Journal of the American Dietetic Association 106(9):1371-9.
- ↑ Krebs-Smith SM, Guenther, Subar AF, Kirkpatrick SI, Dodd KW. (2010) Americans Do Not Meet Federal Dietary Recommendations. J. Nutr. 140: 1832–1838.
- "This analysis indicates that nearly the entire U.S. population consumes a diet with fewer vegetables and whole grains than recommended and that a large majority underconsume fruits, milk, and oils relative to recommendations. Young adults have the greatest tendency toward insufficient intakes, although no sex-age group is immune."
- ↑ Note: If one consumes citric acid, for example, the body metabolizes it to carbon dioxide and water. If it consumes potassium citrate, it metabolizes it to potassium bicarbonate.
- ↑ Souci SW, Fachmann W, Kraut H. (2000) Food Composition and Nutrition Tables. Stuttgart, Germany: Medpharm GmbH Scientific Publishers
- ↑ Sebastian A, Frassetto LA, Sellmeyer DE, Merriam RL, Morris RC, Jr. (2002) Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors. American Journal Clinical Nutrition 76:1308-16
- ↑ U.S. Department of Health and Human Services. Dietary Guidelines for Americans 2005. Washington, D.C. Agriculture Department, Human Nutrition Information Service and Health and Human Services Department
- ↑ Oliveira AC, Oliveira AM, Adan LF, Oliveira NF, Siklva AM, Ladeia AM. (2008) [http://dx.doi.org/10.1038/oby.2008.43 C-reactive Protein and Metabolic Syndrome in Youth: A Strong Relationship?> Obesity 16:1094-1098. PMID 18356840
- ↑ Metabolic Syndrome: What is the Metabolic Syndrome? American Heart Association, 2007.
- ↑ Resnick LM, Barbagallo M, Dominguez LJ, Veniero JM, Nicholson JP, Gupta RK (2001). "Relation of cellular potassium to other mineral ions in hypertension and diabetes". Hypertension 38 (3 Pt 2): 709–12. PMID 11566962.
- Note: Type 2 diabetic patients had the lowest intracellular potassium concentrations, comparing with normal volunteers and patients with hypertension without diabetes.
- ↑ 23.0 23.1 Resnick LM, Gupta RK, Bhargava KK, Gruenspan H, Alderman MH, Laragh JH (1991). "Cellular ions in hypertension, diabetes, and obesity. A nuclear magnetic resonance spectroscopic study". Hypertension 17 (6 Pt 2): 951–7. PMID 2045175.
- ↑ Hu,G.; Jousilahti,P.; Peltonen,M.; Lindstrom,J.; Tuomilehto J. (2005) Urinary sodium and potassium excretion and the risk of type 2 diabetes: a prospective study in Finland. Diabetologia 48:1477-1483. PMID 15971060
- ↑ Heidemann C, Hoffmann K, Spranger J, Klipstein-Grobusch K, Mohlig M et al. (2005). A dietary pattern protective against type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)--Potsdam Study cohort. Diabetologia 48(6):1126-34 PMID 15889235
- ↑ Esmaillzadeh A, Kimiagar M, Mehrabi Y, Azadbakht L, Hu FB, Willett WC. (2006) Fruit and vegetable intakes, C-reactive protein, and the metabolic syndrome. American Journal of Clinical Nutrition 84:1489-1497. PMID 17158434
- ↑ }Fallo F, Della MP, Sonino N, Bertello C, Ermani M, Vettor R, Veglio F, Mulatero P. (2007) Adiponectin and insulin sensitivity in primary aldosteronism. Am J Hypertens. 20:855-61 PMID 17679033
- ↑ http://www.nhlbi.nih.gov/guidelines/cholesterol/atglance.htm#Step8
- ↑ 29.0 29.1 Grundy SM, Brewer HB, Jr., Cleeman JI, Smith SC, Jr., Lenfant C. (2004) Definition of metabolic syndrome: report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition. Circulation 109: 433–438.
- ↑ 30.0 30.1 Cappuccio FP, MacGregor GA. (1991) Does potassium supplementation lower blood pressure? A meta-analysis of published trials. ‘’J Hypertens’’ 9:465-73
- ↑ 31.0 31.1 Whelton PK, He J, Cutler JA, Brancati FL, Appel LJ, Follmann D, Klag MJ. (1997)Effects of oral potassium on blood pressure. Meta-analysis of randomized controlled clinical trials. ‘’JAMA’’ 277:1624-32
- ↑ Cite He MacGregor Others
- ↑ van den Hoogen PCW, Feskens EJM, Nagelkerke NJD, Menotti A, Nissinen A, Kromhout D, The Seven Countries Study Research Group. (2000) The Relation between Blood Pressure and Mortality Due to Coronary Heart Disease among Men in Different Parts of the World. ’’The New England Journal of Medicine’’ 342:1-8 Abstract and Full-Text Here
- ↑ Hansen TW, Jeppesen J, Rasmussen S, Ibsen H, Torp-Pedersen C. (2005) Ambulatory Blood Pressure and Mortality: A Population-Based Study. ‘’Hypertension’’ 45:499-504
- ↑ van den Hoogen PCW, Feskens EJM, Nagelkerke NJD, Menotti A, Nissinen A, Kromhout D, The Seven Countries Study Research Group. (2000) The Relation between Blood Pressure and Mortality Due to Coronary Heart Disease among Men in Different Parts of the World. The New England Journal of Medicine 342:1-8 Abstract and Full-Text Here
- ↑ Khaw KT, Barrett-Connor E (1987). "Dietary potassium and stroke-associated mortality. A 12-year prospective population study". N. Engl. J. Med. 316 (5): 235–40. PMID 3796701.
- ↑ Green DM, Ropper AH, Kronmal RA, Psaty BM, Burke GL (2002). "Serum potassium level and dietary potassium intake as risk factors for stroke". Neurology 59 (3): 314–20. PMID 12177362. [e]
- ↑ 38.0 38.1 Cook NR, Obarzanek E, Cutler JA, Buring JE, Rexrode KM, Kumanyika SK, Appel LJ, Whelton PK. (2009) 10.1001/archinternmed.2008.5234:36 PM4:36 PM Joint Effects of Sodium and Potassium Intake on Subsequent Cardiovascular Disease. Arch Intern Med. 169(1):32-40.
- ↑ Buehlmeier J, Frings-Meuthen P, Remer T, Maser-Gluth C, Stehle P, Biolo G, Heer M. (2012) Alkaline Salts to Counteract Bone Resorption and Protein Wasting Induced by High Salt Intake: Results of a Randomized Controlled Trial. The Journal of Clinical Endocrinology & Metabolism. Published online before print October 1, 2012.
- There was a trend of declining net protein catabolism when high NaCl was combined with KHCO3 (P = 0.052).
- ↑ Bess Dawson-Hughes1, Susan S. Harris1, Nancy J. Palermo1, Carmen Castaneda-Sceppa2, Helen M. Rasmussen1, and Gerard E. Dallal. (2009) Treatment with Potassium Bicarbonate Lowers Calcium Excretion and Bone Resorption in Older Men and Women. J Endocrin Metabolism 94(1):96-102.
Dietary potassium deficiency and skeletal muscle wasting
Skeletal muscle potassium content accounts for >90% of the body's total potassium. As skeletal muscle function requires adequate potassium for efficient neural initiation of muscle contraction, as efficient execution of muscle contractions requires adequate potassium, not surprisingly dietary potassium insufficiency leads to relative muscle weakness and consequent disuse muscle mass reduction. Physiologists have not determined the shape of the curve that relates muscle function, or muscle mass, to dietary potassium intake over the large range consumed by Americans studied in a controlled setting. Possibly contributing, other components present or absent in the different types of foods consumed in generating that large range of potassium intakes play a role in determining the shape of the curve. Whether at current levels of foodpotassium
The molecular mechanisms
Dietary Potassium and Risk of Kidney Stones
[...in progress...]