Two for the Heart: Potassium & Berry Flavonoids

Potassium Prowess in Fighting Heart Disease

Potassium, sodium’s beneficial chemical cousin, can help bring down blood pressure and may reduce the risk of stroke according to several recent reviews.

In one review (1) of published studies, scientists calculated that if Americans could bring their potassium intakes up to recommended levels, cases of high blood pressure would dip by 10%. Right now, about 1 in 3 adults suffer from hypertension.

The authors of this study concluded that boosting potassium and slashing sodium intake is probably the most important dietary choice we can make (after weight loss) to combat cardiovascular disease.

In another review (2), Swedish researchers analyzed the findings of 10 prior prospective studies that included a total of more than 268,000 participants.

The investigators found that increased potassium intake was linked to a reduced risk of stroke, particularly ischemic stroke, which is the most common type. In fact, for every 1000 mg daily increase in potassium intake, the risk of stroke fell by 11%.

Most people aren’t deficient in potassium. But even moderately low levels of this mineral can contribute to salt sensitivity and high blood pressure, a risk factor for heart disease and stroke.

Unfortunately, most Americans aren’t getting enough potassium. A study published this month (3) which looked at the National Health and Nutrition Examination Survey, reports that the vast majority of US adults consume too much sodium and too little potassium.

Putting a “Potassium Plan” into Action

The simplest way to a better balance between these two minerals is to cut back on processed foods and choose more potassium-rich fruits and vegetables. The American Heart Association advises that the daily intake of sodium should be 1,500 mg or less, while the recommended potassium intake is at least 4,700 mg per day or more.

Bananas, strawberries, cantaloupes, papaya, melon, oranges and other citrus fruits top the list of fruits rich in potassium. Potatoes and avocados are packed with this mineral, which can also be found in dairy products, fish, meats and some nuts, beans and seeds.

Curbing Inflammation, Hypertension with Berry Flavonoids

While you’re eating more fruits and veggies to pump up potassium intake, be sure to include berries (blue, black and red), grapes, and vegetables such as eggplant and red onion. That’s because these foods are good sources of red-blue antioxidant pigments called anthocyanins (a type of flavonoid).

Research suggests that anthocyanins can help dampen low-level chronic inflammation – a risk factor for atherosclerosis and thus heart attacks and strokes. In a new study (4) of 150 people with high cholesterol levels, those receiving 320 mg of anthocyanins for 6 months had a 22% reduction in a biomarker of inflammation (C-reactive protein). Placebo-takers had only a 2.5% reduction.

Analyzing data from about 1,900 women, the authors of a second study (5) report a link between higher intake of anthocyanins and a significantly lower blood pressure (both diastolic and systolic). Higher intakes were also associated with biomarkers of artery stiffness. Stiff, less elastic arteries are seen in atherosclerosis.

The authors note that the anthocyanin intakes associated with these heart-healthy benefits are equivalent to eating 1-2 portions of berries daily – a very achievable goal.

References

1. Houston MC and Harper KJ. Potassium, magnesium and calcium: their role in both the cause and treatment of hyper-tension. J Clin Hypertens 10 (7 Suppl 2):3-11, 2008.
2. Larsson SC et al. Dietary potassium intake and risk of stroke: a dose-response meta-analysis of prospective studies. Stroke 42:2746-50, 2011.
3. Cogswell ME et al. Sodium and potassium intakes among US adults: NHANES 2003-2008. Am J Clin Nutr. 96:647-57, 2012.
4. Zhu Y et al. Anti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: A randomized controlled trial. Nutr Metabol Cardio Dis. Epub Aug, 2012.
5. Jennings A et al. Higher anthocyanin intake is association with lower arterial stiffness and central blood pressure in women. Am J Clin Nutr, 96:781-8, 2012.