The U.S. Department of Health recommends that we consume five servings of fruit and vegetables daily to reduce the risk of cardiovascular disease (CVD) due to the fruit and vegetables content of polyphenol chemicals. The way by which polyphenols work has been unknown and most studies to discover this use concentrations of 1-100 micromols, levels not achievable in the body. These authors used more realistic concentrations of 0.1 micromol as the appropriate dose to study the effects of polyphenols on gene expression.
Resveratrol is a polyphenol that comes from the skin of red grapes, wine, apples (Malus domestica), peanuts (Arachis hypogaea), blueberries (Vaccinium spp.) and cranberries (Vaccinium oxycoccus). Quercitin is a polyphenol in apples, tea (Camillia sinensis), onions (Allium cepa), citrus fruit, broccoli (Brassica oleracea) and cherries (Prunus avium and Prunus cerasus). Quercitin is reported to be of benefit in prostatitis by inhibiting mast cell activity.
Coronary heart disease (CHD) results from CVD of the arteries of the heart and stroke results from CVD of the blood vessels to the head and neck. CVD risk is increased by “obesity, high blood pressure, age, gender, tobacco smoking and diabetes”.
The authors treated endothelial cells with ferulic acid, quercetin or resveratrol. Treatment with each resulted in either up-regulation or down-regulation of a number of genes. Treatments were most altered by resveratrol, which up-regulated the gene that produces the enzyme endothelial nitric oxide synthetase (eNOS). eNOS increased nitric oxide (NO) production, relaxing blood vessel walls and increasing circulation. eNOS removes NO from the amino acid, l-arginine and NO inhibits arteriosclerosis.
CONCLUSION: Resveratrol has strong effects at the 0.1 micromolar concentration, increasing circulation and lowering blood pressure. Dietary resveratrol may be important in controlling CVD and hypertension. Quercitin may be important in similar ways.
NOTE: Read about dietary polyphenols and cancer prevention.