Moderate drinking does increase breast cancer risk — but the headlines have skewed the story

    20 August 2015

    Having just one drink a day significantly increases the risk of breast cancer, a major study has found.

    The study, led by Harvard researchers and published in the BMJ, looked at the drinking habits of 88,000 women and 47,000 men.

    It concluded that a drink every day increased the risk of certain cancers among women by 13 per cent. This finding was “mainly driven by breast cancer”, the editorial in the BMJ said.

    The headlines were scary. The BBC summed it up as “Cancer risk ‘even from light drinking'”; the Independent said: “Even drinking a tiny bit of alcohol can cause cancer.”

    These headlines distort the true picture. In particular, the study found no link between moderate drinking and cancer for men except among those who had smoked as well.

    Furthermore, the study must be balanced by evidence we already have about the health benefits of moderate drinking.

    The Dietary Guidelines for Americans, for instance, says: “Moderate alcohol consumption is associated with a lower risk of cardiovascular disease … [and a] reduced risk of all-cause mortality among middle-aged and older adults and may help to keep cognitive function intact with age.”

    Smoking, obesity and lack of exercise have a much greater effect on cancer risk than alcohol.

    In an editorial accompanying the study in the BMJ Dr Jurgen Rehm of the Centre for Addiction and Mental Health in Toronto, Canada, gave a grim warning. Other medics might wonder if he has overplayed his hand here.

    Finally, people with a family history of cancer, especially women with a family history of breast cancer, should consider reducing their alcohol intake to below recommended limits, or even abstaining altogether, given the now well-established link between moderate drinking and alcohol-related cancers.