NMU 251 – Higher Potassium Intake Lower High Blood Pressure and Reduces Cardiovascular Deaths, Especially in Women

Nutrition/Natural Medicine Update No 251 (July 27, 2022)

with Dr. James Meschino

Topic: Higher Potassium Intake Lower High Blood Pressure and Reduces Cardiovascular Deaths, Especially in Women

Source: European Heart Journal (July 2022)

A truly groundbreaking study was published on July 21, 2022, in the European Heart Journal. The study showed that even in the presence of moderately high salt (sodium) diet individuals who routinely consumed ideal amounts of potassium from food each day showed a reduction in high blood pressure and a significant reduction in death from all cardiovascular causes during a 20-year follow-up period. The blood pressure lowering effect of potassium was especially evident for women and women consuming ideal amounts of potassium each day also had a lower risk of cardiovascular events (11% lower risk) than did men (7% lower risk). The study included 24,963 participants (11,267 men and 13,696 women) of the EPIC-Norfolk study, which recruited 40-to-79-year-old patients from general practices in Norfolk, UK, between 1993 and 1997. The average age was 59 years for men and 58 years for women. Participants completed a questionnaire on lifestyle habits, blood pressure was measured, and a urine sample was collected. Urinary sodium and potassium were used to estimate dietary intake.

The results showed that for women, as potassium consumption increased blood pressure went down. When the association was analyzed according to sodium intake, the relationship between potassium and blood pressure was only observed in women with high sodium intake, where every 1-gram (1,000 mg) increase in daily potassium was associated with a 2.4 mmHg lower systolic blood pressure. In men, there was no association between potassium and blood pressure. So, men consuming a high salt diet do not seem to benefit from higher potassium intake in terms of a blood pressure lowering effect, whereas women appear to get this benefit for some reason, which no one can yet explain. However, higher potassium intake appears to help lower the risk of cardiovascular disease over and above any blood pressure lowering effect. Thus, both women and men appear to benefit from adequate intake of potassium regarding the prevention of dying from cardiovascular disease or having a serious cardiovascular event like a heart attack or stroke. More specifically, during the median follow-up of 19.5 years, 13,596 (55%) participants were hospitalized or died due to cardiovascular disease. The researchers analyzed the association between potassium intake and cardiovascular events after adjusting for age, sex, body mass index, sodium intake, use of lipid-lowering drugs, smoking, alcohol intake, diabetes, and prior heart attack or stroke.

After controlling for all these factors, the results showed that men and women with the highest potassium intake had a 13% lower risk of cardiovascular events compared to those in the lowest intake category. When men and women were analyzed separately, the results showed that women had an 11% lower risk of having a serious cardiovascular event (i.e., heart attack, stroke) and men had a 7% reduction in having a serious cardiovascular event. And the amount of salt in the diet did not influence the relationship between potassium and cardiovascular events in men or women. Professor Vogt, a lead researcher on this study, said: “The results suggest that potassium helps preserve heart health, but that women benefit more than men. The relationship between potassium and cardiovascular events was the same regardless of salt intake, suggesting that potassium has other ways of protecting the heart on top of increasing sodium excretion. “The World Health Organization recommends that adults consume at least 3.5 grams (3500 mg) of potassium and less than 2 grams (2,000 mg) of sodium (5 grams or 5,000 mg of salt – sodium-chloride) per day. High potassium foods include vegetables, fruit, nuts, beans, low-fat dairy products, and fish. For example, a 115-gram banana has 375 mg of potassium, 154 grams of cooked salmon has 780 mg, a 136-gram potato has 500 mg, and 1 cup of 1% milk has 375 mg. I have included a potassium food chart below, which features healthy potassium-containing foods.

But some precautionary comments are also required here.Some people have to be careful about consuming too much potassium because they may already have a medical condition where their blood potassium level is too high – a condition called hyperkalemia. If blood potassium levels go to too high it can speed up the decline in kidney function, trigger a heart attack or lead to heart fibrillation and sudden death. So, these are serious and life-threatening outcomes. If you have high blood potassium your doctor has already told you to limit high potassium-containing foods in all likelihood. But some people are walking around with high blood potassium levels, which are very dangerous, and they don’t know it. So, at your next annual physical exam make sure your doctor orders a blood potassium test (which is pretty standard in a routine blood analysis). It is estimated that about 2-3% of the population has high blood potassium levels. People who are most prone to this condition include those with:

• Chronic kidney disease (CKD)– more than half of predialysis CKD patients develop hyperkalemia
• Heart failure
• Diabetes
• And those taking Renin-blocker or ARB-blood pressure lowering drugs, and a few other drugs

But for most of us, more potassium in our diet would be a good thing In our society, adult women consume about 2300 mg per day of potassium, on average, and adult men consume about 3,000 mg per day, on average. This is a bit too low.  According to the National Institutes of Health (U.S.), adult men and women should aim for a daily potassium intake of 4700 mg per day. In most cases, there is no need to take potassium supplements to accomplish this. Consuming more fruits, vegetables, legumes, nuts, fish, and low-fat dairy products will allow you to easily achieve an intake of 4700 mg of potassium per day. Doing so will likely help to keep your blood pressure down and help to reduce your risk of serious cardiovascular events over your lifetime. In addition to providing the reference for this groundbreaking study and other references on potassium, in the text below I have included a list of healthy potassium-containing foods, showing the amount of potassium contained in a standard serving size:

Healthy Potassium-Containing Foods:

• 1 Banana – 375 mg (up to 425 mg in a medium size banana)
• ½ cup Cantaloupe – 215 mg
• Half an Avocado – 345 mg
• 1 raw kiwi – 240 mg
• 1 raw mango – 325 mg
• 1 raw nectarine – 275 mg
• 1 Orange – 240 mg
• I whole Pomegranate – 400 mg
• ¼ cup Raisins – 270 mg
• I medium Artichoke- 345 mg
• ½ cup Bok choy – 316 mg
• ½ cup Broccoli – 230 mg
• ½ cup Beets – 655 mg
• ½ cup Spinach – 420 mg
• 1 Sweet Potato (with skin) – 450 mg
• I medium Tomato – 290 mg
• 1 Baked White Potato (with skin) – 925 mg
• White boiled or Mashed Potatoes (1/2 cup) – 255-330 mg
• ½ Squash – 250 mg
• ½ cup zucchini – 220 mg
• 1 oz of Nuts (almonds, peanuts, hazelnuts, Brazil, cashews, mixed) – 200mg
• 1 oz Pistachio Nuts – 295 mg
• 1 cup Raisin Bran breakfast Cereal – 238 mg
• Salt Substitute (i.e., Morton’s Salt or Potassium Salts) – ¼ teaspoon – 610 mg
• 1 oz Seeds (sunflower or pumpkin) – 240 mg
• I cup soy milk – 300 mg
• Other fruits, vegetables, and legumes contain a respectable amount of potassium. To see the full list, click on this link: https://www.med.umich.edu/1libr/Nutrition/PotassiumHandout.pdf

References:

1. Main Reference: Rosa D Wouda, S Matthijs Boekholdt, Kay Tee Khaw, Nicholas J Wareham, Martin H de Borst, Ewout J Hoorn, Joris I Rotmans, Liffert Vogt. Sex-specific associations between potassium intake, blood pressure, and cardiovascular outcomes: the EPIC-Norfolk study. European Heart Journal, 2022;  https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehac313/6612684

2. Facts About High Potassium in Patients with Kidney Disease (National Kidney Foundation) https://www.kidney.org/atoz/content/hyperkalemia/facts#:~:text=High%20levels%20of%20potassium%20in,heart%20problems%20and%20sudden%20death.&text=There%20are%20often%20no%20warning,high%20potassium%20without%20knowing%20it

3. National Institutes of Health – Potassium. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/#h4