If you're feeling a little guilty about drinking too much this festive season, take heart from a new piece of research: one glass or two of wine a night is good for you and helps boost the immune system.
Although researchers had already established that a glass of wine a day or so can help maintain a healthy heart, this is the first time that anyone had found it was also good for the immune system.
The key seems to be moderation, however. Although alcohol, and especially its levels of ethanol, is a good thing, drinking too much seems to impair the immune system. More surprisingly, you will be healthier by drinking a little alcohol than abstaining.
What, though, is too much or too little? The simple marker is the drink-driving level; you're usually still fit to drive after drinking a glass of wine, but more than that and you could lose your licence.
So drinking a glass or two in the evening is good for you: it boosts your immune system and helps you fight off infection and disease, say researchers at the Oregon Health & Science University, who tested the effects of alcohol on a group of 12 rhesus macaque monkeys, whose immune system is very similar to a human's.
The monkeys were given a smallpox injection, and were then split into two groups: those who could drink as much alcohol, with 4 per cent ethanol, as they wanted and those who were given only sugar water.
As with humans, the macaques' alcohol intake varied within the group. The heavy drinkers had 0.08 per cent ethanol in their blood-the legal limit for drink-driving in the US-while the moderate imbibers had levels of just 0.02 to 0.04 per cent.
The heavy drinkers and the abstainers both had diminished immune responses to the vaccination, but the moderate drinkers had enhanced responses. Their findings add to the growing body of evidence for the benefits of moderate alcohol consumption; earlier studies have found it improves the cardiovascular system and is good for our general health and wellbeing.
(Source: Vaccine, 2013; 32(1): 54)