Alcohol is a toxin that kills cells such as microorganisms, which is why we use it to preserve food and sterilise skin, needles etc. Alcohol kills humans too. A dose only four times as high as the amount that would make blood levels exceed drink-driving limits in the UK can kill. The toxicity of alcohol is worsened because in order for it to be cleared from the body it has to be metabolised to acetaldehyde, an even more toxic substance. Any food or drink contaminated with the amount of acetaldehyde that a unit of alcohol produces would be immediately banned as having an unacceptable health risk
There is no such thing as a safe level of alcohol consumption. The idea that drinking small amounts of alcohol will do you no harm is a myth
The supposed cardiovascular benefits of a low-level of alcohol intake in some middle-aged men cannot be taken as proof that alcohol is beneficial. To do that one would need a randomized trial where a part of this group drink no alcohol, others drink in small amounts and others drink more heavily. Until this experiment is done we don’t have proof that alcohol has health benefits. A recent example of where an epidemiological association was found not to be true when tested properly was HRT. Population observations suggested that HRT was beneficial for post-menopausal women, but when controlled trials were conducted it was found to cause more harm than good.
For all other diseases associated with alcohol there is no evidence of any benefit of low alcohol intake-the risks of accidents, cancer, ulcers etc rise inexorably with intake.
Hopefully these observations will help bring some honesty to the debate about alcohol, which kills up to 40,000 people a year in the UK and over 2.25 million worldwide in the latest 2011 WHO Report.
Professor David Nutt is professor of neuropsychopharmacology at Imperial College London.