Can a Cluster of Grapes Tackle a Cluster of Health Woes?

Measuring markers of heart health

To study how polyphenols, nutrients found in certain fruits and vegetables, affect health, researchers randomly selected 24 men with metabolic syndrome to take a freeze-dried grape polyphenol powder or a placebo (an identical product without polyphenols) for 30 days. This was followed by three weeks of no supplements, and then the groups were switched. All participants took both the polyphenol powder and the placebo during the study, but nobody knew who was taking which product during each 30-day period. Blood pressure and markers of heart disease risk and blood flow were measured at the beginning and end of each 30-day period.

Compared with placebo, after the men took the polyphenol powder supplement they experienced significant changes, including:

• Lower systolic blood pressure (the “top” number in a blood pressure reading)
• Reduced levels of plasma soluble intercellular adhesion molecule, a blood protein that when present at higher levels can indicate a higher risk for heart disease and heart attack
• Improved flow-mediated vasodilation, an indicator of better blood flow and lower heart disease risk

Taming metabolic syndrome

The study results suggest that a grape polyphenol powder may improve blood vessel relaxation, lower blood pressure, and decrease blood levels of adhesion molecules, all of which may improve vascular function and lower heart disease risk in men with metabolic syndrome. This study is small, and the results may not apply to everyone with metabolic syndrome. Still, the findings suggest that something about polyphenols may improve cardiovascular health.

The following tips can help you get more polyphenols into your heart healthy lifestyle plan:

• Dial your doctor. Talk to your doctor before you add any new dietary supplements, powders, or products into your self-care plan. This is especially important if you already take medications to manage chronic health conditions such as diabetes, high blood pressure, or heart disease. Some supplements and medications should not be taken together.
• Diversify your diet. In addition to grapes and grape juice, polyphenol-rich foods and beverages include dark red and purple berries, cherries, pomegranates, plums, cranberries, juices made from these fruits, dark chocolate, broccoli, cabbage, parsley, green tea, and onions. Eat more of these to boost your polyphenol quotient.
• Manage the middle. If you tend to pack on excess pounds around your belly, you may be at higher than average risk for metabolic syndrome. The good news for many people is that belly fat often disappears first when weight is lost. Make your health a priority by adopting one new healthy habit today—take a walk, add berries to your morning oatmeal, play Frisbee in the park, or ride bikes with the kids.

(J Nutr; doi: 10.3945/jn.112.162743)