Just one alcoholic drink a day increases breast cancer risk

X-ray style illustration of female torso with tissue within the breasts highlighted in yellow and red

Dr Rachel ThompsonRachel Thompson is Head of Research Interpretation at World Cancer Research Fund International.

We know that drinking alcohol can increase the risk of several cancers, but surely just one drink won’t hurt? Actually it could – evidence from our new report, the world’s largest review of research on breast cancer, shows that drinking even one alcoholic drink a day can increase your risk of breast cancer.

Why is just one drink so dangerous?

The more alcohol we drink, the greater our breast cancer risk is. However, it’s not just heavy drinkers who are at an increased risk – even one drink can have an impact.

One explanation for this is that when we drink alcohol, it is converted into a toxic substance called acetaldehyde. The more we drink, the more toxic acetaldehyde builds up, which means more cancer-causing damage can be done to the cells. However, even a small amount of alcohol could cause some build up of toxic acetaldehyde, which could lead to cell damage, which is why even one drink increases your risk.

What else increases breast cancer risk?

Our report found strong evidence that other lifestyle factors affect breast cancer risk too.

Exercise was also found to be important for preventing breast cancer. Vigorous exercise that works up a sweat such as cycling, swimming or running helps prevent pre-menopausal breast cancer and both moderate, such as brisk walking, and vigorous levels help prevent post-menopausal breast cancer.

If all women were a healthy weight around 16 per cent of cases of post-menopausal breast cancer in the UK could be prevented. This emphasises the need for policy makers around the world to take obesity prevention seriously, as post-menopausal breast cancer is responsible for more than half a million deaths worldwide each year.

What do we recommend?

There are several things that women can do to help reduce their breast cancer risk. Arguably the most important of these is to avoid drinking alcohol, or reduce alcohol intake. With drinking alcohol being such an ingrained part of so many cultures worldwide, it is vital that we raise awareness of the link between alcohol and cancer. We also know that it increases the risk of a number of other cancers.

Maintaining a healthy weight and getting enough exercise (particularly the vigorous type) are also important for preventing breast cancer. It may be the most common cancer in women worldwide, but our evidence shows that there are steps that women can take to significantly reduce their risk. If everyone were to follow our recommendations a substantial number of cases of breast cancer could be prevented worldwide each year.

> Read our report on breast cancer