“The evidence is very strong and very consistent,” says Paul Whelton, professor of epidemiology at the Tulane School of Public Health and Tropical Medicine. “A higher potassium intake may blunt the effect of excess salt on blood pressure.”
And most Americans get too much salt.
In 1997, Whelton combined the results of 29 trials that randomly assigned people to get high or low levels of potassium, largely from supplements.1 Recent meta-analyses have echoed his findings.2,3
“They found a 3 to 5 point reduction in systolic blood pressure in those who got more potassium,” notes Whelton. “That’s not to be sneezed at.”
In people who reached a total of 3,500 to 4,700 milligrams a day of potassium, the drop was 7 points.²
“Potassium’s effect is bigger in people who have higher blood pressure, bigger in older people, bigger in people who are consuming a lot of salt, and bigger in blacks,” Whelton explains.
What’s more, “a higher potassium intake is very closely linked to a lower risk of stroke,” says Whelton.
In a 2013 meta-analysis of nine studies, people who consumed the most potassium from foods had a 30 percent lower risk of stroke.2
How to up your potassium intake
With evidence mounting, the World Health Organization and the American Heart Association have advised people to get potassium from foods, especially fruits and vegetables.4,5
“Citrus fruits, bananas, cantaloupe, prunes, apricots, raisins, and kiwi are all high in potassium,” notes Whelton, “as are all the dark green leafy vegetables, broccoli, beans, peas, squash, and tomatoes. And potato is a great source if you eat the skin.”
Milk and yogurt are also good sources, he adds, as are nuts, soy foods, salmon, cod, flounder, and sardines.
The daily target is 4,700 milligrams, according to the National Academy of Medicine. More than 95 percent of Americans get less than that.6
“The average is just over 3,000 mg a day for men and 2,300 mg a day for women,” says Whelton. “If we could just bump that up by 1,500 mg a day, we’d be doing pretty well.”
In theory, you could get potassium from a supplement or a (potassium chloride) salt substitute. You could also get it from foods that replace some salt (sodium chloride) with potassium chloride. Odds are, more of those foods will start popping up on shelves before potassium numbers are required on Nutrition Facts labels in mid-2018.
“Supplements are extraordinarily safe as long as you don’t have kidney disease and aren’t taking a drug that interferes with potassium excretion in the kidney,” says Whelton. “If you’re taking an ACE inhibitor for high blood pressure, for example, you should consult your physician.”
But there’s no need to talk to your doctor about eating more fruits and vegetables. To hit your potassium goal without a supplement, we recommend 11 servings of fruits and veggies a day. Sound like a lot? Check out our guide to see how you can reach your target.
1 JAMA 277: 1624, 1997.
2 BMJ 2013. doi:10.1136/bmj.f1378.
3 J. Hum. Hypertens. 17: 471, 2003.
4 Hypertension 55: 681, 2010.
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