by Craig Weatherby
Many plant foods contain compounds called lignans.
Lke vitamin E and the major antioxidants in plant foods, lignans belong to the class of beneficial phyto-chemicals called polyphenols.
A substantial portion of the (admittedly mixed) epidemiological evidence indicates that lignans, like soy isoflavones, may help protect some women’s breast health at some life stages… though the jury is still out (Boccardo F et al. 2006).
Human bodies turn lignans into an estrogen-like compound called enterolactone, which, like the estrogenic isoflavones in soy and many other foods, may protect some classes of women against cancer.
Flaxseed is the most abundant source of lignans by far, sesame seeds come in second, followed by berries, brassica-family vegetables (broccoli, kohlrabi, cabbage, Brussels sprouts, cauliflower), fruits, whole grains, extra virgin olive oil, tea, and red wine (Mazur WM et al. 2000; Owen RW et al. 2000; Milder IE et al. 2005).
Now the results of a small study give women concerned with weight control another good excuse to pack their diets with lignan-rich plant foods.
Lignans may deter diabetes and weight gain
Researchers from Laval University in Quebec recruited 115 post-menopausal women, and used diet questionnaires to estimate the women’s intake of lignans. The women (average age 56.8) also had blood taken to determine their blood levels of enterolactone.
As we said, the body converts lignans to enterolactone, so this digestive breakdown product is a reliable marker for lignan consumption.
The women with relatively high estimated lignan intake had lower body-fat mass numbers and body mass indices (BMI), compared to women with the lowest average intakes.
And, compared to the women with the lowest average blood levels, the women with the highest blood levels of enterolactone had 8.5 kg (18.7 lbs) less body fat, better blood sugar control, and significantly lower blood glucose levels.
As the Quebecois team wrote, “In conclusion, women with the highest enterolactone concentrations had a better metabolic profile including higher insulin sensitivity and lower adiposity [percent body fat] measures.” (Morisset AS, et al 2009)
These findings are exciting because having a lower body fat percentage and greater insulin sensitivity helps prevent metabolic syndrome and its frequent result... diabetes.
While the study does not establish a causal link between lignans and a preferable metabolic profile for women - the link could be due to other dietary or lifestyle factors shared by the lignan-loving women - its results suggest further investigation into the subject.
- Boccardo F, Puntoni M, Guglielmini P, Rubagotti A. Enterolactone as a risk factor for breast cancer: a review of the published evidence. Clin Chim Acta. 2006 Mar;365(1-2):58-67. Epub 2005 Sep 15. Review.
- Fink BN, Steck SE, Wolff MS, Britton JA, Kabat GC, Gaudet MM, Abrahamson PE, Bell P, Schroeder JC, Teitelbaum SL, Neugut AI, Gammon MD. Dietary Flavonoid Intake and Breast Cancer Survival among Women on Long Island. Cancer Epidemiol Biomarkers Prev. 2007 Nov;16(11):2285-92.
- Fink BN, Steck SE, Wolff MS, Britton JA, Kabat GC, Schroeder JC, Teitelbaum SL, Neugut AI, Gammon MD. Dietary flavonoid intake and breast cancer risk among women on Long Islan. Am J Epidemiol. 2007 Mar 1;165(5):514-23. Epub 2006 Dec 11.
- Mazur WM, Uehara M, Wähälä K, Adlercreutz H. Phyto-oestrogen content of berries, and plasma concentrations and urinary excretion of enterolactone after a single strawberry-meal in human subjects. Br J Nutr. 2000 Apr;83(4):381-7.
- Milder IE, Arts IC, van de Putte B, Venema DP, Hollman PC. Lignan contents of Dutch plant foods: a database including lariciresinol, pinoresinol, secoisolariciresinol and matairesinol. Br J Nutr. 2005 Mar;93(3):393-402.
- Morisset AS, et al. Impact of a lignan-rich diet on adiposity and insulin sensitivity in post-menopausal women. British Journal of Nutrition. Published online ahead of print, First View, doi:10.1017/S0007114508162092
- Owen RW, Mier W, Giacosa A, Hull WE, Spiegelhalder B, Bartsch H. Phenolic compounds and squalene in olive oils: the concentration and antioxidant potential of total phenols, simple phenols, secoiridoids, lignansand squalene. Food Chem Toxicol. 2000 Aug;38(8):647-59.