Soy may lower the risk of lung cancer

Men who don’t smoke and eat a lot of soy may have a lower risk of lung cancer, according to a new study.

Soy contains isoflavones, which act similar to estrogen, and may have anti-cancer qualities in hormone-related cancers of the breast and prostate, the researchers note in the American Journal of Clinical Nutrition. Cells in the lung have properties that suggest they may also respond to isoflavones.

Dr Taichi Shimazu, of the National Cancer Centre in Tokyo, and his colleagues, studied more than 36,000 men, 45 to 74 years old and free of cancer at the start of the study.

The researchers followed them for about 11 years, after surveying their food intake, smoking status, medical history and other lifestyle factors. Overall rates of lung cancer were small: 481 men — or about one in 75.

Among the slightly more than 13,000 men who never smoked, there were 22 lung cancer cases among men who ate soy, and just 13 lung cancer cases among those who ate the most.

The authors note that men who eat soy may be more likely to take part in other activities that lower the risk of lung cancer, or may be more likely to eat other healthy food. However, the current study did not gather data on isoflavone supplement use. In other words, the study does not provide enough evidence to suggest a change in eating behaviour, Shimazu said.