'Tis the season to be drinking, but not as much as you've been told to, say Oxford scientists
After years of telling us that a few drinks a day is good for your heart, the medical profession and the government may have to drastically revise their suggested levels of ideal alcohol consump-tion now that new evidence has emerged showing that the current recommendations for safe drinking are well above the optimal level for minimizing disease.
According to a team of researchers from the University of Oxford's Department of Public Health, the ideal amount for all of us to drink is just 5 g a day or just over half a unit. This amounts to as little as one-quarter of a large glass of wine or a quarter-pint of beer a day, which is one-sixth to one-eighth what the UK government and NHS currently recommend. At this time, the government stipulates 3-4 units/day of pure alcohol for men and 2-3 units/day for women as the maximum safe limit. A pint of beer usually contains between 2 and 3 units and a 175-mL glass of wine holds approxi-mately 2 units. The Oxford team figure that lowering our drinking to half a glass a day would avoid 4,579 premature deaths each year.
Best overall level
The research team from the British Heart Foundation's Health Promotion Research Group set out to find the best daily amount for all of us to drink that would see the fewest deaths from the large range of diseases connected to drink in some way. Previous research had focused on the separate health effects of alcohol on specific diseases like heart or liver disease, or certain cancers (see box below).
They carried out a complex analysis of major reviews of the evidence looking at how drinkers fare over time, including studies on both harmful and protective effects of alcohol, using a mathematical model to deter-mine the effects of changing our average alcohol consumption on the death rates due to 11 conditions linked to drinking (see box below). To do this, the team made use of information from the UK's 2006 General Household Survey, which included details on levels of alcohol consumption among English adults, by number-crunching the information against levels of disease risk for different levels of alcohol consumption, as established in these large analyses of the published research.
Lowering drinking levels to their recommendations, they concluded, would save some 3 per cent of people from dying of the 11 conditions.
Got it wrong
This research seems contrary to all the evidence so far that alcohol is good for your heart and other parts of you too. Up to now, medical scientists have focused their research on the effects of alcohol on single diseases. The evidence has shown that moderate drinking can slow heart disease, prevent stroke and type 2 diabetes (the type that starts out not requiring insulin) and help avoid other health conditions (see box, right).
But the mistake was looking at those protective effects in isolation, the Oxford research-ers say. There has been little across-the-board research balan-cing the risks and benefits to see how alcohol affects us as a whole. When the first studies appeared suggesting a protec-tive effect of alcohol on the heart, governments around the world, including the UK, were quick to embrace the findings and set recommendations-without first looking at all the evidence on how alcohol affects the body as a whole and what level fosters optimum health.
"Although there is good evidence that moderate alcohol consumption protects against heart disease, when all of the chronic disease risks are balanced against each other, the optimal consumption level is much lower than many people believe," says the study's lead author Dr Melanie Nichols of the Health Promotion Research Group at Oxford University.
The World Cancer Research Fund, for instance, maintains that there's no safe level of alcohol consumption in terms of cancer risk. Up to 10 per cent of cancers in men and 3 per cent of cancers in women in some European countries are caused by drinking (BMJ, 2011; 342: d1584; doi: 10.1136/bmj.d1584).
Beyond the heart
Nichols also cautions those who carry on drinking heavily because they think it's good for their hearts. "People who justify their drinking with the idea that it is good for heart disease should also consider how alcohol is increasing their risk of other chronic diseases. A couple of pints or a couple of glasses of wine per day is not a healthy option," she says.
So far, the UK government has focused all of its efforts on alcohol abuse and bingeing rather than on setting a policy
of the best level of drinking for overall health. On the basis of
its findings, the Oxford team is urging a rethink of the govern-ment's recommendations.
Although alcohol has evi-dence of preventing or slowing certain degenerative diseases, this latest exercise emphasizes that levels that help prevent one disease might only be helping to bring on another.
Your best path for the holiday season and the rest of the year is to lower your overall consump-tion by having a few drink-free days in the week, limiting your indulgences to a few glasses on drinking days and avoiding binge-drinking, which all of the evidence agrees increases your risk of illness.
Conditions caused by drinking
In 2006, an estimated 170,000 people in England died of the following diseases, all linked with too much booze. The total cost to the NHS: lb3.3 billion.
- Coronary heart disease
- High blood pressure
- Cirrhosis of the liver
- Cancers, including those of the mouth, upper digestive tract, liver, colorectum and breast.
What's drinking good for?
- Your heart
Harvard recommends that one drink for women and up to two for men will cut the chances of having a heart attack or dying from heart disease by about a third and lower the risk of having a stroke caused by a blood clot. Some studies, though, find a protective effect only with wine (Drugs Exp Clin Res, 2003; 29: 173-9), suggesting that it's the antioxidant phenols in grapes-not the alcohol-that does the job.
- Your bones
- Your joints
The researchers believe the protective effect may have something to do with alcohol's ability to lower the body's immune response and arthritis is an autoimmune disease, where the body's immune system begins to attack the cells that line the joints.
WDDTY November 2012 vol 23 no 8