How much alcohol can I really drink?

Image via Universal Pictures

For many of us, alcohol is an enjoyable backdrop to life: wine with dinner, beers with friends, a glass of bubbly to celebrate a special occasion, or nip of something heavier to unwind after a long day.

But alcohol is the fourth-largest cause of disease in Australia after excess weight, smoking and high blood pressure. So, how do you decide whether – or how much – to drink?

Unfortunately, the answer is far from simple and falls into the murky realm of “it depends”. Let’s consider what the science says about the positive and negative effects of alcohol.

Injury

Drinking alcohol increases your risk of accidents and injury. Only tobacco outranks alcohol as the leading preventable cause of drug-related death and hospitalisation in Australia.

Between 1992 and 2001, more than 31,000 deaths were attributed to risky or high-risk alcohol consumption. And between 1993–94 and 2000–01, half a million people were admitted to hospital for alcohol-related injuries.

Cancer

The more you drink, the higher your risk of cancer – and this is a steep exponential curve. So, with each incremental increase in your drinking, there is a marked increase in your risk.

The World Health Organization’s International Agency for Research on Cancer has concluded there is “sufficient evidence” that alcohol causes cancers of the oral cavity, pharynx, larynx, oesophagus, liver, colorectum and female breast.

Unfortunately there is no evidence of a safe threshold; as soon as you start drinking your risk of cancer increases. This includes a 12% increase in the risk of breast cancer with each additional unit of alcohol per day.

Heart disease

The evidence is mounting for a “J- or U-shaped” link between drinking alcohol and developing cardiovascular disease (heart disease, stroke and other blood vessel disease). This means light to moderate drinkers have a lower risk of cardiovascular disease compared with those who drink nothing and those who drink a lot.

These messages are a hard sell. In many other areas of health advice there is happy alignment between health organisations: obesity and smoking being obvious examples. But in the case of alcohol, what protects you against cancer is not necessarily best for your heart.

This means people have to negotiate this tricky path without clear signposts. It’s no wonder some people find it all too hard. Here it’s worth returning to the alcohol advice from the National Health and Medical Research Council on reducing the risk of disease:

Don’t drink more than two standard drinks a day

Don’t drink more than four standard drinks on one occasion

Don’t drink while pregnant or breastfeeding

Don’t drink if you are under 15. And if you’re 15 to 17, delay your first drink for as long as possible.

This advice is population-based, so any individual risk has to be overlaid on top of it. But it is a good start point for guidance.

Reducing death

Finally, the question of how much alcohol would minimise the overall risk of dying prematurely is different to asking what role alcohol plays in the development of disease.

Most public health advice about alcohol, including that outlined above, recommends upper limits of alcohol consumption but does not actually encourage drinking. But the evidence, in fact, goes a bit further. Taking individual risks and priorities into account, it indicates that for people in industrialised countries who have reached a later stage in their life, drinking at least some alcohol (but not too much) is likely to minimise the overall risk of premature death.

Although it’s difficult to make decisions about the health effects of alcohol, we can be heartened by the fact that we have large body of evidence to guide us.

This article originally appeared on The Conversation and has been republished here with permission.