Grapes and blood vessel function

From the California Table Grape Commission:

Eating a modest amount of grapes (about 1 1/4 cups) had immediate favorable effects on how blood vessels function in normal, healthy subjects, and regular consumption of grapes at that level caused even greater improvements in blood vessel function, according to the results of a pilot human study published recently in Vascular Pharmacology. Additionally, eating grapes with a high-fat meal completely prevented the damaging impact to blood flow that was observed with a high fat meal consumed without grapes. These results provide evidence that fresh grapes can have a beneficial impact on markers of cardiovascular disease and may promote heart health. This 21-day placebo-controlled, clinical study, conducted at Ohio State University, looked at the impact of adding grapes to the diet. First, researchers found that consuming 1 1/4 cups of grapes caused significant improvement in brachial artery flow within three hours of consumption. When this same “dose” of grapes was consumed twice daily over three weeks, blood flow and antioxidant capacity were even further improved. Additionally, the researchers also found that consuming grapes with a single high-fat meal (900 calories, 45g fat) dramatically offset the damaging effects of that high-fat meal. Even though a single high-fat meal on its own caused a 50 percent reduction in blood flow response, the addition of grapes to the high-fat meal completely prevented the impaired blood flow. While the development of heart disease involves many different factors, injury and dysfunction of the thin layer of cells that line the interior of blood vessels (the endothelium) is an important marker and a likely contributor to the initiation and/or progression of heart disease. There is evidence that “acute insults” such as drug toxicities, lack of oxygen or a high fat meal can cause dysfunction to the vascular lining and that if repeated, such insults can contribute to disease risk in otherwise healthy individuals. “Our research shows that fresh grapes, consumed in very normal amounts, can beneficially impact the cardiovascular system,” said lead investigator John Bauer, MD. “Our research also shows that consuming a ‘favorable’ food such as fresh grapes can apparently reduce the negative impact of certain ‘unfavorable’ foods.” The grapes used in the study were in a powdered form, made from a representative sample of fresh California grapes that included green, red and blue-black varieties. The grape powder is used to ensure the scientific validity of grape health studies and contains the same biologically active compounds found in fresh grapes. The California Table Grape Commission was created by the California legislature in 1967 to increase worldwide demand for fresh California grapes through a variety of research and promotional programs.