Wine and Health

Red wine, tannins and health

Wine is made up from a huge array of chemicals, some give the wine its colour, some the flavour and others the mouthfeel or texture. While the grapevine did not intend it, some of these chemicals can also be medicinal. The groupings of all these chemicals are known as Polyphenols. In most research into the health benefits of wine two key chemicals come up: Procyanidins and Resveratrol.

In experiments on mice on high calorie diets, those given large doses of resveratrol do outlive mice on a similar diet, and the resveratol almost completely mitigates the effects of a diet that is high in fat. Wine typically has 0.3% of the dosage that was given to mice though, so if you rely on wine as a source of resveratrol you will almost certainly suffer from liver disease before getting anywhere near the target dosage for mice let alone the higher dosages required for humans to benefit.

The second possible polyphenol is a chemical known as procyanidins. This is often associated with wines with tannins. The main benefit include improvements in vascular function by thinning of the blood. This reduces the risk of heart attacks and strokes, thus improving the chances of overall well-being and length of life.

Risk factors for heart disease are also risk factors for a number of other illnesses including dementure, age related molecular degeneration (old age, blindness), obesity.

In wine, polyphenols, and in particular short small procyanidins, are often associated with young tannic red wines. In older wines these chemicals are less plentiful. As wine matures those short tannins clump togehter to form longer chains eventually percipitating out of the wine and forming the sediment. So the type of wine to drink is young red wines that are rich in tannins - sorry to say that if it says 'easy drinking' it is probably not the wine to drink to improve your health. But tannic wines don't need to be hard work to drink. Tannic red wines go great with meat and cheese dishes, so consider drinking these wines with a meal. Not only will the wine taste better, but will also slow down the time it takes for the alcohol to hit your blood stream, reducing stress on your liver.

The grape varieties to look out for in order of importance are: Tannat, Cabernet Sauvignon, Nebbiolo and Malbec. Try wines from the south west of France, Cahors, Italy or Mendoza in Argentina.

What are the limits

Recent press releases by the Centre for Public Health gave a rude awakening to many wine drinkers in the UK. In a surprising set of results it pointed out that while Liverpool and Manchester have England’s highest harmful drinkers at around 8.1% and 8.9% of the adult population respectively, it was the affluent areas that had the most hazardous drinking, with Runnymede, Harrogate and Surrey Heath all at 26% and Guildford, Mid Sussex, Mole Valley Woverly and Leeds above 25% of the adult population.

But what are the limits and what is Harmful and Hazardous drinking?

Sensible drinking is a poorly defined and researched level. It first appeared in the UK in a 1987 pamphlet called the Limit. It was described as the amount to which people should limit their drinking if they wanted to avoid damaging their health.

Hazardous drinking is drinking above recognised sensible levels but not yet experiencing harm. The risk of harm from drinking above sensible levels increases the more alcohol that you drink and the more often you drink over these levels.

Harmful drinking is drinking at levels that lead to significant harm to physical and mental health and at levels that may cause substantial harm to others. Examples include liver damage, cirrhosis, dependence on alcohol, stress or aggression in the family.

So what are the limits in the UK?

Men should drink no more than 21 units of alcohol per week and no more than four units in any one day. Between 22 and 50 units a week, a man is considered a hazardous drinker, and 51 and above they are considered harmful drinker. Men who regularly drink over 8 units a day are at the highest risk of such alcohol related harm.

Women should drink no more than 14 units of alcohol per week and no more than three units in any one day. Between 15 and 35 units a week, a women is considered a hazardous drinker, and 36 and above they are considered harmful drinker. Women who regularly drink over 6 units a day are at the highest risk of such alcohol related harm.

But what is a 'unit'?
The UK advice to the public is based on a term known as a unit. One unit of alcohol is  defined as 10ml (1cl) alcohol by volume (abv), or 8g by weight, of pure alcohol. The table below shows the millilitres of drink for a given abv and the equivalent units.

How much have I drunk?

Pregnant women. It is known that a lot of alcohol can damage a developing baby. A small amount probably does no harm. However, the exact amount that is safe is not known. Therefore, to play safe, advice from the Department of Health is that pregnant women and women trying to become pregnant should not drink at all. According to the Department of Health Pregnancy Book

"Heavy or frequent drinking can seriously harm your baby’s development. When you drink, alcohol reaches your baby through the placenta. But your baby cannot process it as fast as you can, and is exposed to greater amounts of alcohol for longer than you are. And too much exposure to alcohol can seriously affect your baby’s development and can cause Fetal Alcohol Syndrome. Children with this have restricted growth , heart defects, facial abnormalities and learning and behavioural disorders.
The UK’s Chief Medical Officers advise that, as a general rule, pregnant women or women trying to conceive should avoid drinking alcohol. If you do choose to drink, to protect your baby you should not drink more than one or two ‘units’ of alcohol once or twice a week and should not get drunk.

But what do other countries say?

In Australia and New Zealand they use the concept of a standard drink. This is similar to a 'unit' but is based on 10 grams of alcohol while the UK’s unit system is 8 grams (rounded up and based on the specific gravity of ethyl alcohol 0.789). I have put the number of units in brackets beside the standard units. So in Australia the recommendation is:

Men should drink no more than 4 standard drinks (3.2 units) a day, on average. And never more than 6 standard drinks (4.8 units) in one day.

Women should drink no more than 2 standard drinks a day (1.6 units), on average. And never more than 4 standard drinks (3.2 units) in one day.

Everyone should have 1 or 2 alcohol-free days every week.

In New Zealand the Alcohol Advisory Council (ALAC) advise:

Men should drink no more than 3 standard drinks (2.4 units) a day, on average. And never more than 6 standard drinks (4.8 units) in one day.

Women should drink no more than 2 standard drinks a day (1.6 units), on average. And never more than 4 standard drinks (3.2 units) in one day.

Everyone should have 1 or 2 alcohol-free days every week.