Drinking and Breast Cancer
A recent study from Kaiser Permanente points to alcohol consumption as increasing the risk of breast cancer. But this isn't the first time that research suggests a downside for women who regularly imbibe.
Like the Kaiser study, involving some 70,000 women, other large population studies, have also linked alcohol consumption to breast cancer. Among the most recent: the decade-long Women's Health Study and the Iowa Women's Health Study, another long-term study.
In the Women's Health Study, those who drank about two alcoholic beverages per day had a 30 percent total increased risk for breast cancer. That's considered a modest but statistically significant increase and is similar to the Kaiser findings, which were released last week in Barcelona at the European Cancer Conference.
Women who drank alcohol also had a 43 percent higher chance of developing invasive breast cancer, which can be more challenging to treat than less invasive tumors.
According to the Women's Health Study, the link between alcohol and breast cancer was strongest among post-menopausal women taking hormone replacement therapy. This synergistic effect also surfaced in the Iowa study and in a 2003 report of women ages 65 to 79 from the Fred Hutchinson Cancer Research Center in Seattle.
In the Hutchinson study, drinking alcohol at any time in the previous 20 years increased breast cancer risk 30 percent. Also, the more the women drank, the higher the risk.
Alcohol consumption also seems to affect what type of breast cancer develops, according to the Hutchinson study. Drinking alcohol is more strongly linked to lobular tumors and to malignant cells that are sensitive to the hormones estrogen and progesterone.
Despite the hoopla in recent years about the many purported health benefits of wine, there's no evidence that one type of alcohol is better -- or worse -- than another. All appear to hike breast cancer risk equally in women, even in small amounts.
How this occurs is not yet known, but the prevailing theory is that alcohol boosts estrogen production, which raises breast cancer risk.
On a more positive note: Moderate amounts of alcohol can protect the heart, by raising levels of high-density lipoprotein, the so-called "good cholesterol."
Heart disease is the leading cause of death in women and men, so some people claim that drinking can lower the risk. But heart benefits of drinking alcohol don't kick in until after menopause for women.
Even then, quantity counts. For nearly 30 years, women have been advised to limit alcohol to no more than one drink daily; men, to no more than two drinks. (A drink equals five ounces of wine or one 12-ounce beer or 1.5 ounces of distilled spirits such as gin, vodka, whiskey or tequila.)
And no, it's best not to skip drinking during the week and then binge on the weekends. One Australian study of binge drinkers found that consuming more than nine drinks on just one day a week doubled the risk of heart attacks in men. On the other hand, research suggests that women who drink a little -- less than one drink a day -- seemed to protect their hearts and cut the risk of Type 2 diabetes.
-- Sally Squires