           
|
 
Case Control Study:Phytoestrogens and Breast CancerAccording to the prestigious medical journal, The Lancet, high urinary excretion of lignan is associated with a substantial reduction in breast-cancer risk. "There is a substantial reduction in breast cancer risk among women with high intake of phytoestrogens - particularly the isoflavonic phytoestrogens equol and the lignan enterolactone," note investigators in the October 4, 1997 issue of The Lancet. "These findings could be important in the prevention of breast cancer." In this landmark study published in 1997, 144 women aged 30 to 84 who had been just diagnosed with early breast cancer were interviewed and 72 hour urine collection and blood samples were taken before any treatment started. An additional 144 women volunteers (totaling 288 participants) without breast cancer were matched by age and identical postal area code with each breast cancer patient. The non-breast cancer controls were informed only of participation in a "dietary study" with no mention of breast cancer as the study topic. The volunteers' participation involved completing an identical questionnaire and providing the researchers with the same type urine and blood samples required of the breast cancer cases. The purpose of the study was to measure the urinary excretion of lignans and other phytoestrogens in the urine of breast cancer cases, and make comparisons with women without breast cancer. The essential question was whether a high urinary output of lignans (indicative of high physiologic levels) could be correlated with reduced breast cancer risk. The results of the study indicate a resounding yes. A dramatic 300% reduction in breast cancer risk was determined for the women consuming the highest intake of lignan (as indicated by urinary excretion) compared with women whose consumption of lignan was relatively low. This high degree of risk reduction remained valid after adjustment for all other known or suspected risk factors for breast cancer. In the words of the researchers: "Our findings have implications for the control of breast cancer. Early detection by screening, mammography, and adjuvant systemic therapy both reduce breast cancer mortality, but these techniques do not prevent the occurrence of cancer in the first place. They do little to reduce the enormous emotional and physical suffering the disease causes, nor do they reduce the massive financial cost to the community. Prevention is the only way to reduce this suffering and cost. We are aware of no previously investigated preventative factor that has shown the degree of risk reduction similar to that found for some phytoestrogens in this study; and none had equal potential as a simple intervention as phytoestrogens. A cultural movement towards increasing consumption of phytoestrogen-containing food is taking place, encouraged by magazines and other lay media. Our findings go some way towards providing a rationale for these changes." References: 
|
