Red wine

Red wine

We can blame the French for the long-running debate over whether red wine is good for us. For years, many non-French doctors insisted that the low levels of heart disease recorded in France were due to the French preference for putting digestive rather than circulatory disorders on their death certificates. But too many studies now point to small amounts of alcohol ? one to three drinks a day ? being good for the heart for the evidence to be ignored. Still controversial, however, is whether the type of alcohol has to be red wine.

why is red wine good for you?

In moderation, alcohol appears to be good for the heart. About 10 years ago, researchers calculated that people who had two or three drinks of alcohol per day reduced their risk of heart disease by about 17% compared with teetotallers. Subsequent studies have put the figure between 10% and 40%.

Wine got its reputation for being the tipple of choice because it is so widely consumed in France where heart disease rates are low, despite the high consumption of fatty dairy products. But researchers have been divided over whether we should be drinking wine, specifically red wine, or any type of alcohol to look after our heart.

Red wine contains anti-oxidants and polyphenols which help to prevent arterial damage by reducing the likelihood of fatty lesions and blood clots forming in blood vessels and impairing the blood supply to essential organs, such as the heart.

The latest evidence suggests that polyphenols also reduce the production of a substance called endothelin 1 which makes blood vessels constrict. By reducing levels of endothelin 1, red wine may be relaxing key arteries to the heart and helping to prevent them from becoming blocked. So far, the studies have only been done on arterial cells from cattle, but if they can be repeated on human cells, scientists should be able to calculate just how much wine we should drink to protect our heart. Interestingly, only red wine ? not white or rose ? affected endothelin 1 production.

what's the evidence?

Much of the evidence about alcohol and heart disease comes from three types of studies summarised in a large review published in the British Medical Journal in 1996.

Ecological studies relate government data on alcohol sales to national heart disease death rates. The databases are vast and give a good breakdown of beer, wine and spirit drinking, but they only give an average figure for 'per head' consumption and cannot distinguish between people who drink a lot and those who drink a little. Analysis of 12 such studies showed that wine-drinking reduced heart disease deaths, with weaker or non existent protective effects for beers and spirits.

Observational studies (case-control and cohort) check the health and drinking habits of groups of individuals, rather than large anonymous populations. Assuming respondents are honest, they give more accurate and detailed information about their drinking habits than is possible with ecological studies. Case-control studies compare the answers of people with and without different diseases, while cohort studies follow the progress of a group of people with different drinking habits and other health risks to see what diseases they develop.

red wine and heart disease

Two out of three case-control studies included in the review showed that drinking alcohol reduced the risk of heart disease, while the third showed a small trend in the reverse direction. None of the studies picked out wine as being particularly beneficial.

Four out of ten cohort studies showed a definite protective effect for wine, four showed a benefit for beer and four for spirits! Further analysis showed that wine and spirits had slightly stronger data on their side than beer.

This massive review of the evidence therefore concluded that, while moderate alcohol intake seemed to protect against heart disease, the type of alcohol drunk did not seem to matter.

alcohol and strokes

Unfortunately, alcohol seems to be less protective against strokes than heart attacks. Nearly nine out of ten strokes are caused, like heart attacks, by blood clots that block vital arteries. These are called ischaemic strokes and, as with heart attacks, small amounts of alcohol seem to be protective.

But as many as 15% of strokes are caused by burst blood vessels in or around the brain, resulting in a major bleed. Alcohol does not protect against these haemorrhagic strokes and even relatively small amounts of alcohol ? 2 or 3 units per day ? can double or treble the risk of having a haemorrhagic stroke.

red wine and cancer

Heavy drinkers are more likely to get cancers of the upper digestive system ? throat and oesophagus ? than non drinkers. But there is some evidence that moderate wine drinkers are at no greater risk than teetotallers.

In a study of nearly 30,000 Danish people, beer and spirit drinkers were three to five times more likely to get cancers of the upper digestive tract than non-drinkers. But those who took at least a third of their drinks as wine had a risk of cancer slightly lower than that of the non-drinkers.

Wine is known to contain several anti-cancer agents which may offset the harmful effects of the alcohol, and one of these, called resveratrol, has been shown to block tumour growth in the laboratory.

what about the drawbacks of alcohol?

The drawbacks of excessive alcohol intake are all too obvious ? and red wine is no exception. Heavy drinking raises blood pressure and damages the heart, liver, kidneys and brain. It causes impotence and infertility. In pregnancy, it damages the fetus. People who have been drinking are more likely to have accidents, be involved in violence or have sex when they hadn't intended or didn't want to.

Women are currently advised to drink no more than two or three units of alcohol per day (1 unit = a small glass of wine, half a pint of beer, or one pub measure of spirits) and men are advised against going above three or four units per day). But research shows that a lot of people exceed these recommendations.