Postmenopausal women who consume diets rich in a plant chemicals called lignans have a lower risk of breast cancer. A review of 21 studies from the German Cancer Research Center in Neherberg, Germany found that postmenopausal women with high lignan intakes in their diets were 14% less likely to develop breast cancer when compared to women who consumed diets low in lignans. Other studies have shown that diets high in lignans also reduce risk of ovarian cancer and endometrial cancer. (The endometrium is the lining of the uterus.) So, we can see that a high lignan diet impacts the estrogen related cancers in women.
Lignans are a type of plant estrogen and a fat soluble antioxidant that is found in high concentrations in flax seeds, sesame seeds and in smaller amounts of fruits, vegetables such as kale and broccoli, whole grains and legumes such as soybeans. Plant lignans are the principal source of phytoestrogens in the diets of people who do not typically consume soy foods.
Flaxseed is by far the richest dietary source of plant lignans, and lignan bioavailability can be improved by crushing or milling flaxseed. Lignans are not associated with the oil fraction of foods, so flaxseed oils do not typically provide lignans unless ground flaxseed has been added to the oil.
Researchers at the University of Alabama School of Medicine found that lignan rich soy helps postmenopausal women lose weight.
Here is a chart of the top Lignan containing foods:
Although lignans are “plant estrogens” they actually block the effects of a woman’s own more powerful estrogen, thus reducing overall estrogenic effects. And lignans also exert an anti-estrogenic effect, a protective effect on the breast, ovarian and uterine tissues while have a positive effect on bone density in women at risk for bone loss, osteoporosis and hip fracture.
Lignans prevent free radical formation and oxidative stress leading to cell damage. Lignans scavenge free radicals that have already formed. Black sesame seeds contain higher levels of antioxidants than the more common brown sesame seeds. Black sesame seeds can be found in Asian grocery stores.
Lignans also reduce risk of cardiovascular disease which kills more women overall than does cancer. One study showed that adding just 40 grams (two heaping tablespoons) of flax seed meal daily lowered high risk LDL cholesterol by 10%. Flax seeds are also high on Omega 3, 6 and 9 fatty acids which have positive effects on both cardiovascular risk and cancer risk. Similar more recent studies have shown the value of sesame lignans as well.
Clearly, adding lignan rich foods to the diet on a regular basis will reduce the risk of the primary diseases that threaten women’s health.
Add whole flax seeds, ground flax seed meal, sesame seeds and whole sesame butter ( not tahini) to your diet on a regular basis. Add soybeans and soy products. Add kale and broccoli also rich in cancer protective sulphoraphanes, as well as deeply colored apricots, strawberries, all high in protective carotenoids and plant antioxidants. Not only will you reap the benefits of ligans and fatty acids, but you will also be getting Vitamin E and added fiber. When we include a variety of plant based superfoods we get more than one gift from each plant. That is the beauty in the design of nature.
How do you use flax seeds and sesame in your diet? Do you have some special soy or kale dishes?
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Buck, K., Zaineddin, A. et al: Meta analysis of lignans and entrolignans in relation to breast cancer risk. Am, Jl. of Clin. Nut. 2010 May 12
Christie, D., Grant. J, Metabolic effects of soy supplementation in postmenopausal Caucasian and African American Women. Am Jl of Ob&Gyn 2010 April 21
Linus Pauling Institute Reseach Newsletter
Yamashita, K. Comparative effects of flaxseed and sesame seeds Lipids. 2003 Dec;38(12):1249-55.
- Can Eating Soy Affect Breast Cancer Recurrence? (everydayhealth.com)