The type of alcoholic beverage a woman drinks has no bearing on her risk of breast cancer, according to a comprehensive US study.
Researchers from the Kaiser Permanente Medical Care Program in California found that it makes no difference whether a woman drinks wine, beer or spirits; it is the alcohol itself and the quantity consumed that is likely to trigger the onset of cancer.
Dr Arthur Klatsy announced the findings at the 14th European Cancer Conference in Barcelona, having analysed the drinking habits of 70,033 women from diverse ethnic backgrounds over 7 years.
Of the original sample, 2829 were diagnosed with breast cancer, and within this group the study concentrated on those that had a clear preference for one type of drink and drank over one or two alcoholic drinks per day. It was found that there was no difference in the risk of developing breast cancer between wine, beer or spirits, or even between types of wine. A relationship was found, however, between total alcohol intake and breast cancer; with those that drank between one and two alcoholic drinks a day increasing their risk by 10% compared to those that drank less than one drink per day. Also, it was discovered that the risk of breast cancer increased by 30% in women who drank more than three times a day. No variation was found based on age or ethnicity.
“A 30% increased risk is not trivial”, said Dr Klatsy. “To put it into context, it is not much different from the increased risk associated with women taking oestrogenic hormones. Incidentally, in this same study we have found that smoking a pack of cigarettes or more per day is related to a similar increased risk of breast cancer.”
It was also suggested that a 30% increase in the relative risk of breast cancer due to heavy drinking might lead to an approximate 5% extra breast cancer cases in habitual drinkers. Various other studies, as well as research from the same authors, have shown that red wine can protect against heart attacks, but it was thought that different mechanisms were probably at work.
“We think that the heart protection benefit from red wine is real, but is probably derived mostly from alcohol-induced higher HDL (‘good’) cholesterol, reduced blood clotting and reduced diabetes. None of these mechanisms are known to have anything to do with breast cancer. The coronary benefit from drinking red wine may also be related to favourable drinking patterns common among wine drinkers or to the favourable traits of wine drinkers”.
Dr Klatsky stressed that all medical advice needed to be personalised to the individual: “The only general statement that could be made as a result of our findings is that it provides more evidence for why heavy drinkers should quit or cut down.”
He also noted that alcohol was not thought to be a carcinogen, so the detrimental effects are indirect in nature.