More recent evidence has revealed that phytoestrogen from foods may have an anti-cancer effect. The exact role that the phytoestrogen play is poorly understood. Most phytoestrogens act on hormone receptors to regulate their expression. In simple terms, if the expression is low, the phytoestrogen will increase it and if the expression is high, phytoestrogen can decrease the expression. Phytoestrogen are found in commonly consumed foods including soy products and flax.
The early research focused on hormone specific cancers such as breast cancer and prostate cancer when it came to phytoestrogen research. A recent study published in the October issue of Journal of American Medical Association examined a possible protective relationship that phytoestrogens may play in the development of lung cancer. Lung cancer is one of the top three malignancies in women, often regardless of smoking history.
The study enrolled a total of 3509 participants (men and women). They were each required to fill out a food frequency questionnaire that gathered data on 12 commonly consumed phytoestrogens. Follow-up data assessed incidence of lung cancer. Other variables taken into account were history of smoking cigarettes and hormone replacement therapy.
The study found that increased intake of phytoestrogen decreased the risk of developing lung cancer. The phytoestrogens with the highest intake were phytosterols, isoflavones, lignans, and phytoestrogens. The risk was reduced the greatest for participants with the highest quartile (25%) intake of phytoestrogens. Risk of developing lung cancer was decreased by 21-46% depending on which phytoestrogen was consumed in the greatest quantities.
The analysis also differentiated for the different sex. In men phytosterols alone decreased the risk by 24% and isoflavones by 44% in the highest quartile intake. For women total intake caused a decrease in risk of developing lung cancer by 34%, and no single phytoestrogen produced significant differences in risk. These results applied to both never and current smokers. Hormone replacement therapy (HRT) in women increased the protective effect, with HRT and high lignan intake reducing the risk by 50%.
The results of this study further support the protective anti-cancer effect of phytoestrogens. The study does not elucidate on the mechanism, perhaps follow-up studies can address that in better detail.
Posted by Kristopher Foster on March 13, 2006 10:57 PM
