Resveratrol is a member of the polyphenol family, and can be found in a number of plants, but it is most abundant in the skin of red grapes and japanese knot weed. Resveratrol is a deep purple colour, and is responsible for the colour of red wine, and it is because of resveratrol that red wine is considered to be healthy. Resveratrol is commonly associated with cardiovascular health, and recently had a number of studies have investigated these claims with promising results. This article will explain what resveratrol is, and the health benefits of resveratrol.

Resveratrol

As with many polyphenols, resveratrol is a water soluble antioxidant, which can be seem from its structure (see right). The hydroxyl groups (-OH) readily react with harmful radicals by donating the hydrogen ion to them, which will neutralize them. In theory, with 3 hydroxyl groups on the resveratrol molecule should be able to neutralize 3 radicals, which would make it 1.5 times as effective as vitamin C at moping up free radicals – this is yet to be investigated though. High dosages of resveratrol have been taken in several studies with no side effects, which shows it is non-toxic, and it is safe to consume in concentrated forms.

Resveratrol & the digestive system

As resveratrol is taken orally, it first interacts with our body in the digestive system. Here is has shown an ability to reduce oxidative damage in the digestive system. It has also shown the ability to induce apoptosis in cancer cells, even in low dosages. It does this by up-regulating the expression of apoptosis inducing genes – killing the tumor cells. Resveratrol has also shown the ability to inhibit the growth and activity of a bacteria called H.pylori – a common pathogen and the primary cause for stomach ulcers. H.pylori is also known to increase the risk of stomach cancer development, and so by inhibiting its action, resveratrol can indirectly reduce the risk of stomach cancer.

The absorption of resveratrol through the digestive system can vary from person to person, as the bacteria in our digestive system readily metabolise resveratrol. It has been demonstrated that only the probiotic bacteria in our gut are able to do this, and so resveratrol may actually act as a prebiotic. Studies on other polyphenols have shown that they do selectively promote the activity of the probiotics found in our gut, but research specifically on resveratrol has not been conducted.

Due to everyone having a very unique population of bacteria in the gut, the extent of resveratrol absorption will vary dramatically from person to person. The highest recorded amount of free resveratrol absorbed through the digestive system is 2% of total resveratrol consumed. Metabolites and other forms have also been absorbed into the blood stream, but the free radical neutralizing capacity of these is debatable.

There has been much research on the benefits of resveratrol on the cardiovascular system. One of the most obvious and well researched benefits is its ability to neutralise free radicals, which protects the arteries and veins from oxidative damage. Resveratrol has also shown an ability to decrease low-density lipoprotein–cholesterol oxidation and platelet aggregation in blood vessels.  These both cause the vein or artery to narrow, causing blood pressure to increase, and raising the risk of blood vessels rupturing. If platelet aggregation occurs in an important blood vessel such as those supplying the heart the results can be very serious, and even fatal.

Resveratrol can also stimulate nitric oxide production in blood vessels, which causes the muscles in veins and arteries to relax. This results in dilation of the blood vessels, allowing better blood flow throughout the body, especially to the extremities, such as toes and fingers. This also allows helps to reduce blood pressure which reduces this risk of cardiovascular diseases.

There is thorough and clear research showing that resveratrol is a powerful antioxidant which can offer health benefits to the digestive system and cardiovascular system. As resveratrol is consumed orally, the amount which is absorbed through the digestive system can vary because it is readily metabolized by the bacteria in our gut – meaning some people may require higher dosages to have the desired cardiovascular benefits. High dosages of resveratrol have shown to be non-toxic, and safe for human consumption.

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Main image courtesy of Dannymol