Assessing drinking patterns 'simple and fast' way to determine risks of alcohol consumption

Helena Conibear looks at the issues surrounding safe levels of alcohol consumption.

By Helena Conibear

07 Mar 2014

If you reduce your drinking, even from mild-moderate levels or stop drinking, will you be healthier and live longer?

How is it that we can have firm health messages such as "don't smoke" but not messages such as "don't drink alcohol"?

"Can it be true that alcohol in moderation, at the least does not increase our risks of major diseases, or our risk of dying overall?"

Most countries in Europe have, however, established low risk drinking guidelines. Are these guidelines based firmly in science? Can it be true that alcohol in moderation, at the least does not increase our risks of major diseases, or our risk of dying overall?

Across Europe we cannot even agree on the size of a drink - which varies from 8g in the UK to 12g in Denmark or 10g in France, but daily low risk guidelines are fairly similar across Europe, namely one to two drinks a day for women (20-24g) and two to three for men (30g).

This is because since the 1970s a growing body of evidence has suggested that healthy adults who drink little and often (a drink a day) live longer than those who don't drink, or indeed who drink heavily.

It has been contended, that it is other lifestyle factors (confounders) that can account for this benefit, namely that moderate drinkers live healthier lives, eat a more Mediterranean diet, and are better educated for example.

Studies since the 1990's have carefully adjusted for these potential confounders as a result, but let us look at two very large research studies whose results have been published in the last six months to see if they support current guidelines.

One of these studies looks at the alcohol consumption each decade for the 111,953 men and 268,442 women from eight countries participating in the European prospective investigation into cancer and nutrition (EPIC) study. More than 26,000 deaths were observed during an average of 12.6 years of follow-up.

The results illustrate the effect of alcohol consumption on different diseases - namely a protective, or beneficial effect for cardiovascular diseases (men had a 24 per cent lower cardiovascular disease mortality and risk was 34–46 per cent lower among women) and a negative effect on cancers (men and women had a two to five times higher risk of dying due to alcohol-related cancers at levels higher than light drinking).

So how can consumers and policy makers balance the risks? By looking at the 'all cause' mortality risk of drinking moderately. This is essentially, your risk of dying from any cause. The EPIC study clearly showed, what we know as the J shaped curve, i.e. a higher risk of death if you don't drink, or if you drink heavily, with the lowest risk for those who drink moderately

A commentary on the paper concluded that, "For the age group included in the EPIC study (older adults), accounting for prevalent illness, the risks of death were lowest in men with lifetime patterns of alcohol consumption of greater than two to 24g a day and consumption at enrolment of 15–20g a day; corresponding levels for women were greater than one to 12g a day and around 10g a day.

The evidence indicates that it is advisable to avoid heavy drinking throughout life. If taken as causal, these findings are consistent with most public health advice about alcohol, except that most advice recommends an upper limit to alcohol consumption, but does not actually encourage drinking.

In fact, the evidence goes further than this and indicates that, in later life, on average and bearing in mind the priorities and risks of specific individuals, drinking at least some alcohol, but not too much, is likely to minimise the overall risk of death."

The second study is important as it looks at how we drink. Two individuals can drink the same amount in one week – one in a heavy session, the other a glass a day – this pattern has profound health effects.

This study entitled 'Alcohol consumption, heavy drinking, and mortality: Rethinking the J-shaped curve', offers an analysis based on data from more than 110,000 subjects in the USA, of whom 3,364 died during a follow-up period of up to nine years,

They evaluated the relation of 'heavy drinking' and 'non heavy drinking' (five drinks or more per session) to the risk of all-cause mortality. The key findings of the analyses were that there was a positive and linear increase in risk of mortality for subjects consuming heavy amounts of alcohol, with the risk increasing as drinking at this level was more frequent.

For non-heavy drinkers, there was a J-shaped relation with mortality. The point at which the non-heavy drinkers' risk of mortality exceeded that of abstainers was between four and five drinking occasions week.

The authors concluded that, "Promoting less harmful drinking patterns by reducing heavy drinking frequency is an appropriate harm reduction strategy, and assessing drinking pattern by determining the frequency of heavy and non-heavy drinking is a simple and fast way to determine risk and promote less risky drinking behaviour."