No wonder we celebrate National Watermelon Day on August 3rd: What could be better than a plate of juicy watermelon slices on a hot summer day? Now science is uncovering reasons why this simple, delicious and nutritious fruit might be particularly satisfying when temperatures soar: Lower blood pressure benefits.

Previous research indicates that blood pressure averaged higher — as much as five points higher — when temperatures ranged over 78 degrees. While diets with reduced salt, less meat, and more fruit and vegetables, can help balance blood pressure levels, one particular food — watermelon — was sized up for potential targeted benefits in a study just  published in the American Journal of Hypertension.  For six weeks, 14 morbidly obese men and women (average age 58 years old) were fed powdered watermelon pulp — the equivalent of 2.3 lbs of fresh fruit — daily. Compared to a control group, those on the “watermelon diet” enjoyed a 9% decrease in blood pressure.

Why might this be? Watermelon features a cast of nutritional characters — vitamins A and C, citrulline, lycopene — that may act independently or in concert to relax arterial blood vessels to lower pressure. Indeed, the red flesh of the watermelon contains twice the amount of lycopene as tomatoes, compared gram-for-gram.  In addition to possible heart health, lycopene may also support male fertility, minimize sunburn damage, and reduce prostate cancer risk. Citrulline, an amino acid concentrated in the watermelon rind, may  help enhance blood flow by suppressing certain enzymatic activity.

Bonus:  Lace up to lower blood pressure! Walking as little as an hour and 15 minutes a week — equivalent to three 25 minute walks — could be enough to make medication unnecessary for some hypertension sufferers. Watch our video to learn more about managing blood pressure.

Published August 1, 2012