Some intense activity on Twitter today discussing wine and health. Lots of views expressed, although proper discussion of topics like this in 140 characters is quite tricky.
The discussion was prompted by a tweet by Cam Haskell about a meta-analysis looking at the evidence for health benefits of antioxidants. It is here.
This is not a research study itself, but a critical analysis combining all the results from high quality studies to see if there is a general trend.
Most people are under the illusion that dietary antioxidants are good for health. This meta-analysis shows that vitamin A, beta-carotene and vitamin E may even have negative health effects. This isn’t new – those who have followed the literature for a while will have picked this up.
Many wine commentators are under the potential misconception that red wine is good for health because of its antioxidant properties. The evidence suggests that this isn’t the case.
Now there’s certainly good evidence that moderate drinkers live longer than teetotallers. It’s a consistent finding, and is known as the J-shaped curve. This is the shape of the line on the graph that results from plotting mortality against alcohol consumption.
As alcohol consumption increases, mortality decreases. Then, as alcohol consumption increases yet further, mortality starts to increase.
But there are many confounders here. People who tend to drink modestly also tend to exhibit other healthy behaviours. And people who drink wine tend to be richer, which correlates positively with health status.
Good studies control for such confounding factors. But not all studies are good. If you are trawling the scientific literature looking for evidence about wine and health, you need to be able to discriminate the good studies from the less good ones.
The antioxidant story resonates with people’s preconceptions. There are other components in wine that might make it healthful, not least among which is alcohol itself. Many studies show that there’s a health benefit with beer and other alcoholic drinks. But still, despite the evidence against any benefit from dietary antioxidants, that’s the story people cling to.
Do we need wine to be good for health, though? This is another discussion that was worked through on twitter. Most wine lovers drink wine because they enjoy it, not because it’s good for them. But the healthful properties of wine may be recruiting new drinkers, especially in Asia, it seems.
There was also discussion on the negative effects of wine. Alcohol can be harmful to health, and some were suggesting that it it gets off lightly compared with smoking and illegal drugs such as cannabis. Some wine trade figures suggested that if wine were devised de novo today, it would be banned.
I disagree. There is a healthy level of alcohol consumption, whereas with smoking there is no healthy level of consumption. The spectre of David Nutt was raised. Professor Nutt famously suggested that alcohol was more harmful than heroin. But heroin is a class A drug consumed by a few. Alcohol is almost universally consumed by adults.
I quite like the suggestion that wine is a virtuous intoxicant, as argued by Roger Scruton. Wine is quite unlike other mind-altering drugs which are dishonest in nature, because they claim to elevate the perception of the user such that the user enters a transcendental realm. These drugs lie to us because they tell us about another world outside our own. Instead, wine tells us about the true world; the one we live in, revealing more about it. Wine, when drunk in company, leads to an opening out of the self to others.