Soy does have isoflavones, to help prevent lung cancer, but it also has phytates and phytoestrogen, which cause mineral deficiency and increased female hormones respectively.  So to be prudent eat soy sparingly as isoflavones are also available in many other foods recommended by Changing Habits and Cyndi O’Meara

Soy men have less risk from lung cancer

According to new Japanese research, men who ate large amounts of soy foods and, of course, did not smoke are at less risk of getting lung cancer. So, eat that soy and put out those cigarettes!

Dr. Taichi Shimazu, from the National Cancer Center, in Tokyo, Japan, and fellow Japanese colleagues performed a study of 36,177 men and 40,484 women in Japan who were 45 to 74 years of age. 

At the beginning of the study, none of the subject had any signs of cancer. The baseline years were from 1995 to 1999.

Their research was published online on January 13, 2010, in the American Journal of Clinical Nutrition.

Their paper, entitled “Isoflavone intake and risk of lung cancer: a prospective cohort study in Japan (doi: 10.3945/ajcn.2009.28161), was authored by Taichi Shimazu, Manami Inoue, Shizuka Sasazuki, Motoki Iwasaki, Norie Sawada, Taiki Yamaji, and Shoichiro Tsugane.

They said in the paper that summarized their research: “Although case-control studies support the idea that soy foods or isoflavone intake is associated with a decreased risk of lung cancer, little evidence is available from prospective cohort studies.”

And, “Moreover, no prospective study has addressed this association in men.”

Source: William Atkins, 8 February 2010, http://www.itwire.com/science-news/health/36610-waatkins