HomeArticlesCancer and heart disease: Can alcohol help you or hurt you?

Cancer and heart disease: Can alcohol help you or hurt you?

Drinking four glasses of wine a day can increase your chances of getting breast cancer by about 50%.


We have heard drinking is good for your heart. We have heard it may even protect you against diabetes. But we also know that alcohol is a major driver of heart disease, certain cancers and diabetes.

So, what is going on?

Between 2002 and 2010, HIV and tuberculosis were the leading cause of death in South Africa. But in 2010, the situation started to change. By 2012, it was estimated that close to half (43%) of deaths in South Africa could be attributed to non-communicable diseases and conditions, such as respiratory diseases, diabetes, cardiovascular disease and cancers, according to a 2016 study published in The Lancet. HIV and tuberculosis was responsible for about a third (34%) of deaths, and 14% of people died as a result of communicable diseases, perinatal conditions, maternal causes and nutritional deficiencies. 

It is fairly widely recognised that smoking, unhealthy diet and a lack of physical activity fuel noncommunicable diseases. What is less well understood is that alcohol use, and especially heavy use of alcohol, is also driving these conditions, especially cardiovascular disease, cancers and diabetes.

Some noncommunicable diseases are entirely attributable to alcohol. Mental disorders such as foetal alcohol syndrome, alcohol dependence syndrome, conditions related to withdrawal from alcohol, alcohol-related liver disease and alcoholic cardiomyopathy (a form of heart disease caused by alcohol abuse), cannot occur if a person does not drink alcohol.

For other illnesses, alcohol use is not necessary for the condition to develop, but its role can be causal. In such cases, there is typically a dose-response relationship between risk of onset, death from the noncommunicable disease and the volume of alcohol consumed.

Breast cancer is one of the conditions where alcohol and health issues collide. Any alcohol consumption raises a woman’s breast cancer risk. Drinking four glasses of wine a day would increase a woman’s chances of getting breast cancer by about 50%, according to a 2016 study published in the journal, Addiction. So, if a given woman’s risk of getting breast cancer is say 10%, four drinks a day would increase that risk to about 15%. Similarly for colorectal and liver cancer.

Drinking two alcoholic drinks a day increases a woman’s risk of breast cancer by about 20%.

For some, this would be a risk worth taking, but it is certainly something that women should be informed about so that they can make healthy choices.

The evidence is now clear that alcohol use is also a risk factor for cancers of the mouth, pharynx and oesophagus, where the odds of contracting those forms of cancer increases by 300% to 600% when the patient is drinking four standard drinks per day, according to the 2016 Addiction journal article.

The situation with diabetes is more complex: moderate alcohol consumption is associated with a reduced risk of Type II (adult-onset) diabetes. Studies have shown that the protective effect of alcohol is greatest at around two drinks per day for men and women.

But consumption of greater amounts of alcohol — four or more drinks per day for women and five or more for men — increases the risk of this type of diabetes by about 20%, according to a 2013 study in the scientific journal, Alcohol Research: Current Reviews. With regard to neuropsychiatric conditions (mental disorders attributable to diseases of the nervous system), research has shown that alcohol use increases the risk of epilepsy and unipolar depressive disorders.

For cardiovascular and circulatory diseases, alcohol use can have detrimental and beneficial effects. Drinking larger amounts of alcohol can cause hypertensive heart disease, cardiomyopathy, conduction disorders and dysrhythmias (conditions relating to an irregular heart beat). But the same amount of alcohol can have different effects on men and women.

On the other hand, alcohol use can have beneficial effects on ischaemic heart disease (a condition caused by the narrowing or blocking of blood vessels due to the deposit of cholesterol on their walls), ischaemic stroke and haemorrhagic and other nonischaemic stroke. This is because alcohol increases HDL (good) cholesterol, prevents blood clots and increases the rate of breakdown of blood clots. But this depends on drinking patterns and the amount drunk. It cannot be assumed for all drinkers, even at low levels of intake.

Finally, alcohol use has also been shown to have a harmful effect on various digestive and skin diseases such as cirrhosis of the liver, chronic pancreatitis (inflammation of the pancreas that does not heal or improve), gall-bladder and bile duct disease.

So, what can be done about this? We need to promote low-risk drinking for adults who do choose to drink. A woman should not drink more than about seven 120ml glasses of wine, or seven 340ml beers, per week, and no more than two and a half on any day. Adult men should drink less than 12 340ml cans of beer, or the equivalent thereof per week, and no more than three on any given day.

At a population level, “best buys” are likely to include moderate tax increases on alcohol to boost prices, bans on alcohol marketing, except at points of sale, better controls on the availability of alcohol and also more rigorous drunk-driving countermeasures.

The alcohol industry will probably cry foul and claim that we are becoming a “nanny state”. But a large proportion of their profits, especially in a country such as South Africa, depends on people engaging in heavy drinking, especially over weekends. The consequences not only affect individual consumers, but also those with whom they interact, and broader society.

According to well-known epidemiologist, Jürgen Rehm, a 10% reduction in alcohol consumption would result in a 7% reduction in premature alcohol-related noncommunicable deaths globally — a saving of 43 000 out of more than 600 000 deaths.

The South African health department’s national strategic plan for the prevention and control of noncommunicable diseases calls for a 20% reduction in alcohol consumption in the country. This clearly won’t be realised in the short term.

But some movement to reducing drinking levels in South Africa, and especially drinking at heavy levels, is urgently needed. If we don’t decrease the burden of alcohol-related noncommunicable diseases, noncommunicable conditions will have a devastating, ever increasing impact on the country.

Professor Charles Parry is director of the Alcohol, Tobacco and Other Drug Research Unit at the Medical Research Council of South Africa.

Charles Parry is the Director of the Alcohol, Tobacco & Other Drug Research Unit at the South African Medical Research (SAMRC) and is a former Acting Vice-President of the SAMRC (2012-2014).