Despite earlier reports, more recent studies leave little doubt that alcohol intake increases breast cancer risk.

According to a recent article in the Journal of the American Medical Association (Vol. 286, No. 17: 2143-2151), just one to two drinks can increase risk for some women.

In the article, authors Keith Singletary, PhD, and Susan Gapstur, PhD, from the University of Illinois in Urbana-Champaign, reviewed recent research on alcohol and breast cancer.

According to the authors, “…findings reported since 1977 from populations in several countries provide…evidence that breast cancer risk is higher for women consuming moderate to high levels of alcohol (three or more drinks per day) compared with abstainers.”

The authors also say there is a direct relationship with the amount of alcohol consumed and increased risk. This risk exists even with as little as one or two drinks daily.

It is likely that 2% of women in the US can consider alcohol as having a role in the development of their breast cancer, the authors say. But in Italy the figure is probably closer to 15%. That would mean one in six breast cancers are related to alcohol. The authors say this is because the average alcohol intake in Italy is higher than in the US.

Some other important observations include the fact that it doesn’t make any difference what type of alcohol you drink. Nor does it make any difference whether you are pre- or post-menopausal.

How does alcohol do this? The authors say there may be several reasons. Alcohol could lower certain vitamin levels. Another reason may be that women who consume large amounts of alcohol may not eat a healthy diet.

Alcohol may also influence levels of hormones, such as estrogen, which may increase breast cancer risk.

The authors say alcohol may suppress the body’s own built-in self-defense and repair mechanisms.

What can women do? Women who consume alcohol should do so only occasionally, they write. According to the researchers, this is no more than one drink daily. Women who don’t drink shouldn’t start.

The authors write that drinking less, or not drinking, is one of the few known ways to lower breast cancer risk.