Does Soy Intake Influence Lung Cancer Survival?

logo1267406_mdA new study published online in the Journal of Clinical Oncology concluded that Chinese women who consumed more soy before being diagnosed with lung cancer lived longer compared with those who consumed less soy. The researchers said “To our knowledge, this is the first study to suggest an association between high soy consumption before lung cancer diagnosis and better overall survival.” “Although the findings are very promising, it’s too early to give any dietary recommendations for the general public on the basis of this single study.”

The cancer incidence of 74,941 women in the Shanghai Women’;s Health Study was tracked and information about usual dietary intake of soy foods (soy milk, tofu, fresh and dry soybeans, soy sprouts, and other soy products) was collected in person at study enrollment and two years later. Using the Chinese Food Composition Table the soy food and isoflavones content of various food products was calculated.  Four hundred forty four women were diagnosed with lung cancer during the study period and the median time between the first dietary assessment and cancer diagnosis was 5.8 years. Patients were divided into 3 groups according to soy food intake prior to lung cancer diagnosis for analysis. The highest and lowest leveks were equivalent to approximately 4 ounces or more and 2 ounces or less of tofu daily. Those with the highest soy food intake had markedly better overall survival compared with those with the lowest intake–60% of patients in the highest intake group and 50% in the lowest intake group were alive at twelve months after diagnosis.

The risk of death decreased with increasing soy intake until the intake reached a level equivalent to 4 ounces of tofu daily. No additional survival benefits were found by a higher intake. Factors such as a higher soy food intake, lower prevalence of cigarette smoking, and postmenopausal hormone replacement in this population may influence the results when the methodology is applied to a different population. Further research is planned.

Tags: , , ,

Comments are closed.