Scientists from Imperial College London have recommended that women in their thirties be warned about the link between alcohol consumption and breast cancer risk, even at modest levels. The research suggests that roughly a quarter of breast cancer cases could be prevented through lifestyle changes, and experts emphasise that health messaging must target women at specific life stages when their habits typically shift, particularly during the 30s to 50s when weight gain and alcohol consumption become more pronounced.

The study, analysing data from over 110,000 women, found that whilst women in their 20s consume more alcohol than any age group, those in their 30s face greater risk due to the combined effect of drinking and excess weight. A single glass of wine nightly increases breast cancer risk by 15 per cent, with each additional daily drink adding a further 10 per cent increase. The research attributed these risks to mechanisms including acetaldehyde (a toxic breakdown product of alcohol) damaging DNA, and fat cells producing an enzyme that converts testosterone into oestrogen, which can stimulate tumour growth—an effect particularly pronounced after the menopause, where obesity is linked to a 30 per cent higher breast cancer risk.