The last 20 years has seen a huge increase in wine consumption in the UK, so the news that red wine had health benefits was greeted with enthusiasm by many, including myself. As with all health news, it's a bit of a mixed message, but here are the main things to consider, and as always, the main issue appears to be MODERATION.
The good bits
Antioxidants
All wine contains antioxidant chemicals. Much of the antioxidant benefit of wine comes from the chemical resveratrol. This is found in the seeds and skin of grapes. Red wine has a high concentration of resveratrol because the skins and seeds ferment in the grape juices during the red wine-making process. This prolonged contact results in significant levels of resveratrol in the finished product.
White wine also contains some resveratrol, but because the seeds and skins are removed much earlier in the white wine making process, the levels of resveratrol in the finished product are much lower. In addition to resveratrol, wine contains at least three other antioxidants: saponin, catechin, and guercetin.
Antioxidants reduce the oxidation process during which reactive particles known as 'free radicals' are released. Free radicals cause damage to healthy cells, so antioxidants play a major role in limiting cell damage. Antioxidants also prevent the oxidation of LDL cholesterol ('bad cholesterol'), a process that leads to cholesterol deposition in the walls of arteries, causing coronary heart disease.
This activity may in part account for what is known as the 'French Paradox'. French wines contain higher levels of antioxidants than many other wines. Studies have shown that in areas of France where the diet is high in fat, those people who drink red wine with their meals have a lower incidence of heart attacks than those in other parts of the world with similar diets.
Cancer prevention
Laboratory studies have suggested that resveratol has anti-cancer properties. It seems to work in several ways; by minimising the DNA mutations that lead to cancer, by provoking cell death in cancer cells, and by blocking the formation of small blood vessels around the tumour that carry nutrients to the tumour. It also has the ability to inhibit the process by which the tumour spreads to a different site (metastasis).
Much larger studies are required to confirm the anti-cancer benefits of resveratrol, but the early results look hopeful. A particularly reliable laboratory finding has been the ability of resveratrol to cause certain cancer cells to 'self-destruct'. The cancer cells disintegrate, and the particles are 'mopped up' by other cells. This effect has been seen, in laboratory experiments, in breast cancer cells, skin cancer (melanoma) cells, and leukaemia cells.
Other laboratory studies have shown suppression in the growth of prostate cancer cells. Researchers from the State University of New York have concluded that 1 glass of red wine a week may help to prevent colon cancer, but this has not been confirmed as yet.
Blood thinning
Resveratrol has blood-thinning properties. It acts by preventing platelets (the blood cells that are involved in clot formation) from sticking to each other. Resveratrol may therefore reduce the risk of strokes and heart attacks by this mechanism.
Phytoestrogen effects
Resveratrol is a phytoestrogen. These are plant-based substances that are chemically similar to oestrogen, and so can have some oestrogen-like activity in the human body.It has been suggested therefore that red wine may benefit some medical conditions that are associated with a low natural oestrogen level, such as osteoporosis and premature menopause. This hasn't been proved as yet.
For those who don't like red wine, the good news is that resveratrol is also found in peanuts, blueberries and cranberries.
