It's long been known that red wine in moderation can be good for us. This may be due to the powerful effect of an antioxidant called resveratrol which is found in the skin of grapes.

What is resveratrol?

Grapes and other fruits and seeds contain resveratrol in their skins. It shields the plant from invading fungi and strong sun.

You can get resveratrol from eating fruits with dark coloured skin such as grapes, blueberries, blackberries and cranberries. It’s also found as a supplement.

Why do I need resveratrol?

Nutritionists believe resveratrol is good for our health due to its powerful antioxidant properties. Antioxidants are substances that protect us from disease-causing particles (called free radicals) that destroy DNA and other cells in our bodies.

It’s also thought resveratrol lowers sugar and fat levels in the blood and reduces blood pressure. A European study* recently tested the theory on obese men by giving them resveratrol supplements. The results were impressive - the supplements caused a metabolic effect similar to that seen with exercise and calorie restriction - including lowering the men’s blood pressure and blood sugar levels.

This followed on from previous studies in which resveratrol supplements were shown to protect obese mice from the usual negative effects of weight gain and also prolonged their lives.

Scientists speculate that resveratrol may trigger the production of a protein called SIRT1 which improves metabolic function and keeps cells healthy (which is what happens when you exercise and follow a calorie-restricted diet).

Although it may be tempting to drink a lot of red wine to try to achieve these results - unfortunately the amounts required would render you paralytic. So supplements are definitely the way to go.

In a further study, resveratrol at high doses inhibiting abnormal blood vessel growth in the eyes of mice, suggesting it may protect our eyes from conditions of old age such as macular degeneration.

Can too much resveratrol be harmful?

More research is needed on resveratrol to determine its full impact and any side-effects.The participants of the study on obesity (see above) took a daily supplement of 150mg.