What Resveratrol Can Do for You
Scientists around the world have discovered many ways that resveratrol may benefit heart health. In 1995, Canadian researchers reported that resveratrol could protect against heart disease by reducing platelet aggregation, an early step in the development of blood clots that can lead to heart attacks or strokes. In 2002, German researchers found that resveratrol stimulates production of nitrous oxide, which helps relax arteries. In 2003, Italian researchers provided evidence that resveratrol could reduce the risk of atherosclerosis by keeping inflammatory cells from sticking to artery walls. Later that year, American researchers reported that resveratrol could slow the progression of atherosclerosis by inhibiting the spread of vascular smooth muscle cells.
Resveratrol may also pay a role in cancer prevention, by inhibiting certain enzymes that activate some carcinogens and by promoting the excretion of other carcinogens. When cancer has already taken hold, resveratrol can arrest the cell cycle of cancer cells (allowing for DNA repair) and induce apoptosis (programmed cell death). Resveratrol can also inhibit cancer cell proliferation and angiogenesis, the process through which tumors support their growth by creating new blood vessels.
Resveratrol and Bioavailability
In vitro studies have shown resveratrol to have many potent actions, and resveratrol is well absorbed in the gut; however, some researchers question whether the effects shown in the laboratory can take place in the body. In the May 2005 issue of the journal Molecular Nutrition & Food Research, scientists from the German Research Center of Food Chemistry wrote, “The oral bioavailability of resveratrol is almost zero due to rapid and extensive metabolism”. In other words, very little resveratrol makes it into the blood.
The German researchers were not the first to discover this, however. In 2004, researchers at the Medical University of South Carolina acknowledged the low bioavailability of oral resveratrol, but suggested that resveratrol accumulates and provides benefits along the digestive tract. And in the November 2000 issue of the journal Xenobiotica, Italian researchers provided evidence that flavonoids and other components of grapes and wine improve the bioavailability of resveratrol.
Some researchers have taken a different approach to the problem of oral resveratrol bioavailability by skipping the stomach altogether. Using a delivery system known as PEGylated liposomes, supplements can deliver resveratrol through the mucous membranes in the mouth and directly to the blood. However, even resveratrol delivered directly to the blood is rapidly metabolized by the liver and removed from the blood in as little as 30 minutes.
However, low bioavailability does not mean resveratrol is useless; some researchers feel that it means investigators should shift their focus. For example, the previously mentioned German researchers suggest that future research focus on the effects of resveratrol metabolites.
The Bottom Line
Grape seed extract contains powerful antioxidants and can reduce oxidation, strengthen and repair connective tissue and promote enzyme activity. It can also help moderate allergic and inflammatory responses by reducing histamine production. These actions help fight disease and boost your immune system. If you want to improve your chances against disease, enhance your health and fight the effects of aging, grape seed extract can help.
Grape Seed Extract and Resveratrol Fast Facts
Uses and Benefits: Grape seed extract is an antioxidant, an anti-inflammatory, an antihistamine and an antiallergenic. It also improves circulation, promotes healing, restores collagen and strengthens weak blood vessels.
Sources: Grape seed extract is available at most health food stores. There are many different brands with different levels of active constituents, so ask your local supplement provider for recommendations.
Some of the beneficial nutrients in grape seed extract are also available in other foods. Resveratrol is found in grapes (and grape products such as red wine and purple grape juice), peanuts and some berries.
OPCs are found in many types of foods – usually in the peels, skins or seeds – but usually only in extremely small amounts. Some of the best sources are seasonal fruits such as grapes, blueberries, cherries and plums. Grape seeds contain the highest known concentration (95 percent) of OPCs, and pine bark the second highest (80 to 85 percent). Food processing and storage time reduce OPC bioavailability.
Other Names: Another name for OPC complex is Pycnogenol. This was the name originally given to the complex by Dr. Jacques Masquelier, the first to scientifically discover OPCs. Dr. Masquelier patented the process of extracting OPCs from the bark of maritime pine trees, and Pycnogenol is now a trademarked name for OPC products extracted from pine bark.