Regular consumption of soy foods seems to reduce a woman’s risk of getting cancer of the endometrium, the lining of the uterus, according to a study conducted in Shanghai. This benefit is most pronounced among overweight women.

The estrogens women produce are known to play a key role in the development of endometrial cancer, the researchers note in this week’s British Medical Journal. Given that soy foods contain isoflavones with both estrogen-like and anti-estrogen activities, the effect high intake of such foods have on the risk of endometrial cancer has been unclear.

To investigate, Dr. Xiao Ou Shu, from Vanderbilt University in Nashville, Tennessee, and colleagues in China compared the soy intake of 832 women with endometrial cancer randomly selected from the Shanghai Cancer Registry, with that of 846 unaffected women.

The team found that the higher the consumption of soy foods, the lower the odds endometrial cancer.

Compared with women who consumed no more than 5.9 grams of soy protein per day, those who consumed 6.0 to 10.2, 10.3 to 16.0, or more than 16 grams per day were 7 percent, 15 percent, and 33 percent less likely to develop cancer, respectively.

These risk reductions were even greater when the analysis was limited to overweight women.

Although the results suggest an anti-endometrial cancer effect for soy foods, further studies are needed to confirm that the benefit is increased in overweight women, the researchers point out.

SOURCE: British Medical Journal, May 29, 2004.