Researchers from around the world have been examining the role of red wine in promoting longevity and good health but also its connection to migraines, breast cancers and high blood pressure.

Heart disease

Scientists believe the polyphenols found in red grapes' skin are cardioprotective. The Copenhagen City Heart Study tracked more than 13,000 people over 12 years and found those who drank 3 to 5 glasses of wine a day had half the risk of dying from coronary heart disease or stroke as those who never drank. Canadian cardiologists analysed more than 13 studies to find red wine drinkers had 32 percent less atherosclerosis than non-drinkers.

Will any old red do?

Initial studies by London researchers suggest cabernet sauvignon may be the most effective at protecting against heart disease. All reds suppress endothelin-1, a protein in blood vessels that leads to hardening of the arteries, but the polyphenols in cab sav more than halve its production.

Longevity

Harvard researchers have found that resveratrol switches on an enzyme that slows the ageing process, extending the life of yeast cells by as much as 70 percent. If the same process is found to work as well in humans, researchers believe this may extend the average human life span by up to ten years.

Relatively little is known about the effects of resveratrol in humans - much of the basic research has been done on cultured cells. Resveratrol appears to be well absorbed by humans, but it's rapidly metabolised and cleared from the body. Even so, David Sinclair, a leading researcher into resveratrol at Harvard, thinks it may accumulate to high levels over time.

Alzheimer's

A study at the Mount Sinai School of Medicine found that adding cabernet sauvignon to the drinking water of mice with Alzheimer's-type brain changes reduced brain deterioration. Earlier studies had found that resveratrol, which is abundant in the skins of red grapes, activates the brain enzyme MAP kinase, which helps the regeneration of neural cells.

Prostate cancer

A daily glass of red may halve a man's risk of prostate cancer, according to a US study of almost 1500 men. Resveratrol may clear the body of cancer-causing free radicals, reduce cell proliferation and work as an anti-inflammatory. It may even reduce levels of male hormones such as testosterone that fuel the growth of prostate cancer.

Teeth

The tartaric acid in wine can wear away tooth enamel and red wine's tannins can also cause staining. However, researchers at the University of Laval in Quebec believe the polyphenols in red wine may help dental health. Lab tests show they reduce gum inflammation and stave off periodontal disease.

Migraine

A Lancet study tested migraine-sufferers who believed that red wine, but not alcohol in general, caused their headaches. Red wine triggered a typical migraine in nine out of eleven sufferers, whereas none of eight migraine-sufferers who were tested with vodka experienced an attack.

Some researchers believe that red-wine headaches may be caused by the bacteria in wine. Vintners are working on the problem— a red wine with a genetically-modified strain of yeast (MLO1) performing the function of bacteria was released this year.

Breast cancer

A 22-year study of 98,000 women found those who drank 1-2 glasses of wine a day had a 21 percent greater chance of breast cancer. Other forms of alcohol carry a similar risk, yet women tend to favour wine over beer or spirits. Many breast cancers are fuelled by oestrogen; alcohol may increase blood oestrogen levels.

Histamine

One glass of red may be enough to induce sneezing, flushes, headaches, diarrhoea, skin itching and shortness of breath in some people.

Researchers at the Vienna Dermatologic and Paediatric Allergy Clinic tested the role of histamine in 28 patients with a history of red wine intolerance: 22 had higher histamine levels 30 minutes after drinking red, with a small number getting a slight asthma attack. Lead researcher Dr Felix Wantke says the histamine levels in red wine can be at least ten times higher than those in white wine.

How much is the right amount?

For teetotallers, there is no reason to start popping corks. The antioxidants in red wine occur in other food and doctors are wary of touting alcohol, given that it can raise blood pressure, increase the risk of some cancers and damage nerve cells and vital organs. If you already drink, a glass or two—no more—may not only bring an immediate "feel-good" sensation, it could deliver a long-term bonus.

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