Fruit, vegetables, nuts, beans, lentils, and low-fat dairy products are all high in potassium.  All have been found to be consistently associated with lower blood pressure, low stroke risk, and lower mortality.  Potassium supplements have been found useful for the typical person with borderline or elevated blood pressure in a number of small scale studies.  The large majority of such patients do not get enough potassium in their diets and consume far too much sodium, which potassium helps to offset.   Potassium could be of major benefit for the treatment of high blood pressure due to its low cost and low side-effects.  

Of course, individuals eating sizeable amounts of vegetables, fruits, nuts, beans, lentils, and other natural foods get considerably more potassium that people consuming large amounts of processed food.  People on such healthy diets and without high blood pressure appear not to benefit from a potassium supplement.

The ideal amount of a supplement to take appears to be 1000-2000 mg of extra potassium per day (about 25-50 mmol or millimols).  The average person consumes 50-100 mEq (milliEquivalents) per day or 2000 to 4000 mg.  Simply drinking two glasses of orange juice daily adds about 1000 mg potassium), which was actually found to decrease blood pressure somewhat in just two weeks.  No Salt salt substitute, which is mainly potassium chloride, is by far the least expensive way to add potassium to your diet.  One-half to three-quarters of a teaspoon added to your food each day at a cost of 5 cents will provide the recommended 2000 mg.  I keep the No Salt now on the counter with the spices and add 1/4 to 1/2 teaspoon to every dish, depending on the size.  It gives a mildly salty flavor.

Potassium not only lowers blood pressure and cuts the number of deaths from stroke, but potassium also improves bone density, the opposite effect from sodium.  Avoiding salt or at least getting 1000-2000 mg of added potassium is very good for treating and for avoiding osteoporosis.  Potassium is also thought to help avoid some types of kidney stones.  Patients on diuretics or with kidney disease should use potassium supplements only under physician supervision since kidney disease can cause potassium levels to get too high.

Potassium Helps Blood Pressure in Those Not Restricting Sodium: JAMA 5/28/97 277:1624 Whelton. Reviewed 33 DB PC studies covering a total of 2609 patients treated with potassium supplements. Potassium decreased systolic 3.11 mmHg and diastolic 1.97mmHg.  It's impact appears to increase the longer individuals remain on the supplement.  It helps those with high sodium intake especially. Whelton says supplements do not help normotensives. An article, used by the herbal medicine Industry's Energy Times to promote taking supplements, was published in Hypertension ’98;31:131-8. Energy Times, typical for herbal medicine magazines, claims the article reported lowering BP for 300 women with potassium supplement. But the actual article found potassium only of benefit for those women with low intakes of potassium and that calcium and magnesium supplements did not of benefit individuals despite low intakes.  Energy Times conveniently left out those additional facts.  Fruits, nuts, vegetables, beans, lentils, and dairy are all high in potassium.

Potassium Chloride and Potassium Citrate Same Effect: In a randomized, crossover study comparing potassium chloride (e.g. 1 1/4 teaspoon No Salt/day) with potassium citrate (96 mmol/d, each for 1 week) in 14 hypertensive adults, blood pressure dropped from 151/93 mm Hg with a 24-hour urinary potassium of 81 mmol. to 140/88 mm Hg with potassium chloride (24-hour urinary potassium: 164 mmol) and 138/88 mm Hg with potassium citrate (24-hour urinary potassium: 160 mmol). Potassium citrate is similar to the potassium in fruits and vegetables. Thus, increasing the consumption of foods high in potassium is likely to have the same effect on blood pressure as potassium chloride. Effect of Short-Term Supplementation of Potassium Chloride and Potassium Citrate on Blood Pressure in Hypertensives. He FJ, Markandu ND, et al. St. George's Hospital Medical School, London, United Kingdom. Hypertension. 2005 Feb 21

Potassium Found Highly Protective in Scottish: 11,300 followed for 8 years. Smoking, HBP (especially systolic), and fibrinogen found to be other important risk factors for mortality. Potassium measured in urine was strongly protective. Inactivity, both leisure and at work, were associated with higher mortality. Modest alcohol intake was protective against heart disease. Height was protective. Weight, like alcohol, showed a U-shaped mortality curve. Lower salt excretion and early menopause very weakly associated with higher mortality. Oddly, uric acid (very high not good), energy intake both were not significant on longevity. Vit C, E, and carotenoids were a little protective. BMJ 1997;315:722-729 (20 September)

Blood Pressure Lowered by Potassium Supplement: 6 week DB PC 59 healthy adults took 24 mmol slow-release KCl per day. Systolic decreased 7 mmHg and diastolic 6 mmHg, similar to the impact of a blood pressure medicine. Epidemiological and clinical trials suggest an inverse relationship between dietary K intake and blood pressure (BP). Author says 24 mmol (1000mg/d)= 5 servings of fruits or vegetables in potassium content. King’s College London. The effect of low-dose potassium supplementation on blood pressure in apparently healthy volunteers. Naismith DJ, Braschi A. Br J Nutr. 2003 Jul;90(1):53-60

Blood Pressure Lowered by Potassium Supplement in Beijing: 150 pt with borderline to mild HBP (systolic 130-160, diastolic 80-94) DB PC 12 week 60 mmol potassium (2500 mg/d). Systolic BP dropped 5 mmHg and diastolic 1mmHg. Effect of potassium supplementation on blood pressure in Chinese: a randomized, placebo-controlled trial. Gu D, He J, Wu X, Duan X, Whelton PK.

Blood Pressure Lowered by Potassium Supplement in Kenya: 84 pt with mild HBP DB potassium 60 mmol or bendrofluazide for 28 weeks. Both groups major decrease in BP with diastolic dropping 108 to 88 with potassium. No side-effects or biochemical changes from potassium, but diuretic caused 8 cases hyperuricemia, 4 hyperglycemia, and 3 hypokalemia. Potassium supplementation versus bendrofluazide in mildly to moderately hypertensive Kenyans. Obel AO, Koech DK.

Low Potassium Linked to 50% Higher Stroke Risk: 5600 elderly >65yo followed 4-8 years. Those on diuretics and who had low serum potassium (< 4.1 mEq/L) or low intake (< 2.4g/d) had RR 2.5 for stroke (p<.0001). Those not on diuretics but low potassium RR 1.5 (p<.005). Serum potassium level and dietary potassium intake as risk factors for stroke. Green DM, Ropper AH, Kronmal RA, Psaty BM, Burke GL; Cardiovascular Health Study. Neurology. 2002 Aug 13;59(3):314-20

Low Potassium Intake Linked to 28% Higher Stroke Risk: 19 year follow-up of 9805 NHANES I U.S. national random selection health study. Hazard ratio for those consuming low potassium diet was 1.28. (p<.03). Dietary potassium intake and risk of stroke in US men and women: National Health and Nutrition Examination Survey I epidemiologic follow-up study. Bazzano LA, He J, Ogden LG, Loria C, Vupputuri S, Myers L, Whelton PK. Stroke. 2001 Jul;32(7):1473-80

Potassium Supplements Lower Stroke: A Harvard study with 8 years of follow-up of men taking potassium supplements during the first 2 yr found 69% fewer strokes with the supplements. Men in highest potassium intake (4.3 g or 9 serving fruits & vegetable) had 38% fewer strokes than lowest intake (2.4 g or 4 servings).

"No Salt," Potassium Baking Powder, OJ, Healthy Food Cheapest Sources: Potassium is high in most natural foods including almost all fruits, vegetables, beans, peas, etc. It is low in refined flour and of course absent in sugar and oils. By far the cheapest potassium supplement is to simply buy a $4.00 11 oz. container of "No Salt," which is primarily potassium chloride. You get 38,500 mg for $1 or about 5 cents a day for the recommended 2000 mg amount (3/4 teaspoon).  Supplements at Wal-Mart potassium (99mg. each) 250 tablets cost $4 (6,500 mg for $1). For my recommended 2,000 mg/d supplement for a person consuming the standard high salt American diet, you would have to take 20 a day! At local health food store, the same potassium capsules cost 2.5 to 5 times as much as Wal-Mart and 15 to 30 times as much as No Salt! Potassium baking powder at a few health food store costs $4.50 (6600 mg for $1).  This is potassium bicarbonate which some research says works better than potassium chloride.  It also helps you avoid the sodium in regular baking powder if you use it in baking. Two cups orange juice gives you about 1000 mg of potassium or half of what I would recommended as a daily supplement for most people. Prescription supplements, a real waste of money at 30 cents per tablet even for the generic (Micro-K or Slow-K are slightly more) at wholesale, have 750 mg of potassium chloride per capsule or about 385 mg of potassium (10 mEq) and doctors generally give at least two per day.  To get my recommended 2000 mg/d with generic Micro-K would cost $1.50 per day vs. 5 cents with No Salt.  The usual dietary intake of potassium for an adult is 50-100 mEq/day or 2000-4000 mg./day. Excessive levels are rare if kidneys are working normally. However, in chronic renal failure, systemic acidosis, acute dehydration, extensive burns, adrenal insufficiency or with a potassium sparing diuretic medication such as spironolactone, triamterene, or amiloride, there is a danger of overdosage.

Potassium, Magnesium, Fruits, Vegetables Protect Against Bone Loss: In the Framingham study, patients had bone mineral densities measured and then remeasured 4 years later. Magnesium, potassium, fruit and vegetable intakes were significantly associated with bone mineral density at baseline and among men, with lower bone loss over four years. Tufts Univ. The acid-base hypothesis: diet and bone in the Framingham Osteoporosis Study. Tucker KL, Hannan MT, Kiel DP. Eur J Nutr. 2001 Oct;40(5):231-7

Potassium Bicarbonate Stops Calcium Loss: 18 women given potassium bicarbonate 60-120 mmol/d (3,000-6,000mg/d potassium). UCSF. Improved mineral balance and skeletal metabolism in postmenopausal women treated with potassium bicarbonate. Sebastian A, Harris ST, Ottaway JH, Todd KM, Morris RC Jr.

Low Potassium Blood Level Dangerous, Not High Potassium: Potassium was measured in 9,297 patients in the HOPE Study, and was <3.5 in 137. The combined primary outcome (cardiovascular death, myocardial infarction, or stroke) increased with hypokalemia (22.6% vs 15.5%, p 0.023, hazard ratio 1.44). Hyperkalemia conferred no hazard Hypokalemia was more prevalent in women, in hypertensives, & with diuretics. Ramipril benefit was independent of potassium. Less patients on ramipril had hypokalaemia (p = 0.005), including those on diuretics (3.8% v 6.5%, p = 0.07). New Trial Data on Prevention: Potassium and CV Risk in Hope. Mann JF, Yi QL, Sleight P, Dagenais GR, Probstfield J, Gerstein HC, Lonn EM, Bosch J, Yusuf S; HOPE investigators. Munich. Pacing Clin Electrophysiol. 2003 Jul;26(7 Pt 1):1565

Low and High Potassium Blood Levels are Risks: NHANES I 18-year Follow-up Study of 2,836 subjects. All-cause and cardiovascular mortality were assessed controlling for sociodemographic status, smoking, medical history, and clinical characteristics. A low potassium blood level, 2.7-3.7 mmol/L (N = 477); middle, 3.8-4.4 mmol/L (N = 1,982); and high, 4.5-5.4 mmol/L (N = 377). The cardiovascular mortality rate per 1,000 person-years adjusted for age, gender, and race for the high serum potassium group (8.1) was significantly higher than the middle (5.3) and low (6.5) serum potassium groups. Further analysis, controlling for age, gender, race, smoking status, cholesterol, and history of diabetes, renal disease, and cardiovascular disease, revealed that the increased cardiovascular mortality among subjects with moderately increased serum potassium was most prominent in those reporting use of diuretics (hazard ratio, 2.65; 95% confidence interval [95% CI], 1.20 to 5.85) and those with abnormal renal function (hazard ratio, 1.89). Serum potassium and cardiovascular mortality. Fang J, Madhavan S, Cohen H, Alderman MH. J Gen Intern Med. 2000 Dec;15(12):885-90

Thomas E. Radecki, M.D., J.D.

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