Lignan is a chemical found in the cell walls of plants. Plants contain several different families of natural substances among which are compounds with weak estrogenic or antiestrogenic activity in humans. These substances, termed phytoestrogens, include certain isoflavonoids, flavonoids, stilbenes, and lignans. The best-studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans. Their perceived health beneficial properties extend beyond hormone-dependent breast cancer, osteoporosis, and prostate cancer to include brain function, cardiovascular disease, immune function, inflammation, and reproduction.

Food Source
Plant lignans come from sources such as flax seed, whole grain cereals, rye, legumes, seeds and nuts, berries, vegetables and fruits. Several hundred individual lignans have been discovered but the main research has focused those from flaxseed (Linum usitatissimum). The main lignan from flaxseed is secoisolariciresinol diglucoside (SDG). When SDG is ingested it is metabolised by microflora in the human gut into the mammalian lignans, enterodiol and enterolactone. These two metabolites are then absorbed from the gut and transported to the liver where they undergo further reactions before entering circulation. The appropriate lignan dosage has yet to be determined, but a range of 10 mg to 30 mg daily dose of SDG may be sufficient to deliver health benefits. Lignans are also present in high concentration in Norwegian spruce bark (Picea abies).
   Have you considered adding flax seeds to your soups? They make a tasty and crunchy addition. Wait a few minutes after you add the seeds so that they have time to absorb the water and soften up. Flax seeds are wonderful stool softeners and help reduce constipation.

Lignan extract supplement
You will find lignan extract being sold for the purposes of healthy cholesterol maintenance and cardiovascular health. Plant lignans are converted to enterolignans that have antioxidant and weak estrogen-like activities, and therefore they may lower cardiovascular disease and cancer risks. It's easy to consume lignans through foods. I don't see the need to take lignan supplements. Just add flax seeds to your soup or use ground flax seeds in cooking. Eat more whole grain cereals and whole grain bread rather than consuming white bread.

Anti-inflammatory
Cancer Causes Control. 2014. Urinary lignans and inflammatory markers in the US National Health and Nutrition Examination Survey (NHANES). Mammalian lignans were inversely associated with markers of chronic inflammation

Breast cancer
Women who eat healthy amounts of plant foods rich in lignans reduce their risk of developing breast cancer.

Postmenopausal women who eat foods rich in estrogen-like plant chemicals called lignans have a modestly decreased risk of developing breast cancer. In an analysis of 21 studies published in the past 13 years, it was found that postmenopausal women who reported the highest intakes of dietary lignans were 14 percent less likely to develop breast cancer than those with low intakes. Phytoestrogens are plant-based compounds that are structurally similar to estrogen and may have weak estrogen-like, as well as anti-estrogen, activity in the body. Some studies have linked high phytoestrogen intake to a lower risk of breast cancer. Lignans are one of the three main types of phytoestrogen. Flaxseed and sesame are particularly high in them, and the compounds are also found in whole grains, berries and some other fruits, a number of vegetables such as broccoli and kale, and green tea. American Journal of Clinical Nutrition, 2010.

Prostate gland
Lignan binds to testosterone in the body — and in many prostate-cancer patients, testosterone is what fuels tumor growth. Researchers have often suspected that lignan might stop prostate tumor cells from multiplying out of control. Mice, genetically programmed to develop prostate cancer, have far less disease when their diets contain flaxseed.

Lignan and fibroids
Lignan and isoflavone excretion in relation to uterine fibroids: a case-control study of young to middle-aged women in the United States.
American Journal of Clinical Nutrition 2006.
The objective of this case-control study was to evaluate the relation between uterine fibroid risk and phytoestrogen exposure. Two overnight urine collections (48 h apart) from 170 uterine fibroid cases and 173 controls were analyzed for isoflavonoids (ie, daidzein, genistein, equol, and O-desmethylangolensin) and lignans (enterodiol and enterolactone). Results: Unadjusted isoflavone excretion did not differ significantly between cases and controls, but cases excreted significantly less lignans than did controls. The trend for a reduced risk of uterine fibroids with increasing quartiles of lignan excretion was significant. Conclusions: Our findings suggest a modest inverse association between lignan excretion and uterine fibroid risk. Whether this relation represents an effect of lignans per se or of other constituents of lignan-containing foods on the development of uterine fibroids remains to be determined. No association was found between isoflavone excretion and uterine fibroids; however, the intake of soy foods, the primary source of isoflavones, was low in this population.

Weight gain or loss
Am J Epidemiol. 2015. A Prospective Investigation of the Association Between Urinary Excretion of Dietary Lignan Metabolites and Weight Change in US Women. Results from animal studies have consistently suggested that lignans play a role in the regulation of in body weight, but evidence from human studies has been limited. We examined the associations between urinary excretion of enterolactone and enterodiol, the major intestinal microbial metabolites of dietary lignans, and 10-year prospective weight change using data from 2 well-characterized cohort studies of US women: the Nurses' Health Study (2000-2010) and Nurses' Health Study II (1997-2007). Our data suggest that higher urinary excretion of lignan metabolites, especially enterodiol, is associated with modestly slower weight gain.

Types of Lignans
There are a number including enterolactone, enterodiol, yangambin, lariciresinol, pinoresinol, matairesinol and secoisolariciresinol.

Lignans Metabolism
Isoflavones and lignans are metabolized by colonic bacteria to more biologically active metabolites. Isoflavonoids and lignans can be quantified in various body fluids. Typically, high concentrations of isoflavonoids in urine and serum are associated with soy consumption, and high concentrations of lignans are associated primarily with intake of whole grains and other fiber-containing plant foods. Lignan excretion is associated positively with dietary fiber intake. The complex interactions between the colonic environment and the external and internal factors that modulate it contribute to significant variation in serum and urinary phytoestrogen levels among individuals.
    Many foods have lignans including sesame seeds. Sesame lignans have anti-inflammatory properties.

Lignan in flax
Flaxseed is one of the richest sources of lignan precursors. Flaxseed has gained attention in the area of cardiovascular disease primarily because it is one of the richest known sources of both alpha-linolenic acid (ALA) and the phytoestrogen, lignans, as well as being a good source of soluble fiber. Human studies have shown that flaxseed can modestly reduce serum total and low-density lipoprotein cholesterol concentrations, reduce postprandial glucose absorption, decrease some markers of inflammation, and raise serum levels of the omega-3 fatty acids, ALA and eicosapentaenoic acid. Data on the antiplatelet, antioxidant, and hypotensive effects of flaxseed, however, are inconclusive. There are products sold that claim high lignan flax seed oil.

Rye Bran Lignans
Rye bran contains a high content not only of dietary fiber, but also of plant lignans and other bioactive compounds. Blood concentrations of lignans such as enterolactone have been used as biomarkers of intake of lignan -rich plant food. Some studies show a correlation between high fiber intake and cancers of the upper digestive tract. A number of prospective epidemiological studies have clearly shown a protective effect of wholegrain cereals against myocardial infarctions. A corresponding protective effect against diabetes and ischaemic stroke ( brain infarct) has also been demonstrated. It seems reasonable to assume that these protective effects are associated with one or more factors in the dietary fiber complex.

Acatris Flax Lignan Product Proven Bioavailable - Press release by Acatris, Inc
Minneapolis, 2006 – A recent human clinical pilot study conducted by the Kanda Ishin Clinic in Tokyo, Japan has shown that flax lignans from Acatris’ LinumLife product are bioavailable. This research demonstrates that supplements and products containing the LinumLife EXTRA ingredient are absorbed into the blood stream. Flaxseed, specifically its lignans, are promoted to have beneficial effects on acne, reduce hair loss in men and women, encourage breast health, relieve postmenopausal symptoms, promote cardiovascular health and support prostate health in men, but clinical research is needed to prove these claims. “SDG, the main flax lignan has been part of the human diet for centuries,” said Jocelyn Mathern, RD and technical specialist for Acatris, Inc. “This study demonstrates that LinumLife is absorbed by the body and increases serum levels of enterolactone and enterodiol, mammalian lignans which are linked with health benefits.” Based on research, consumers need a minimum of 50 mg a day of SDG to reap the health benefits attributed to flax lignan ingredients. Acatris, the flax lignan leader, set the gold standard for minimum amount needed for therapeutic benefit and research on the health benefits of flax lignans. Lignans are a group of phytochemicals found in many plants. Each type of lignan has a different structure and different health properties. “The number of products containing flax lignans has grown tremendously in the last few years, including products focusing on women’s health, prostate health and breast health,” said Mathern. “These products help bring this phyto-nutrient - which is often missing in people’s diets due to modern food refinement - to consumers looking for targeted health benefits.” Acatris is working to keep up with consumer interest in flax lignans. As more research is completed on flax lignans, the facts on this “super seed” and its many health benefits will continue to feed a healthy marketplace appetite. Acatris Inc.’s LinumLife EXTRA is produced through a patented production process. A dosage of 250 mg of LinumLife EXTRA provides 50 mg lignans.

Hi Dr. Sahelian, Love your site because it's informative. I have a question. Linumlife SDG Lignans in a study shown modestly to help fight hair loss. The makers of 7-HMR Claim, HMR lignan has a superior bioavailability. I'm curious since SDG and 7-HMR lignans are different if their actions are any different.
    There are a number of different lignans and all do not necessarily have the exact same biological activity. As of 2010, a search on Medline did not reveal any peer-reviewed published human clinical studies with HNR lignan supplement, nor Linumlife SDG Lignan supplements.

Lignan Research study
Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer.
Clin Cancer Research. 2005.
This study examined, in a randomized double-blind placebo-controlled clinical trial, the effects of dietary flaxseed on tumor biological markers and urinary lignan excretion in postmenopausal patients with newly diagnosed breast cancer. Patients were randomized to daily intake of either a 25 g flaxseed-containing muffin or a control (placebo) muffin. At the time of diagnosis and again at definitive surgery, tumor tissue was analyzed for the rate of tumor cell proliferation (Ki-67 labeling index, primary end point), apoptosis, c-erbB2 expression, and estrogen and progesterone receptor levels. Twenty-four-hour urine samples were analyzed for lignans, and 3-day diet records were evaluated for macronutrient and caloric intake. Mean treatment times were 39 and 32 days in the placebo and flaxseed groups, respectively. Reductions in Ki-67 labeling index (34) and in c-erbB2 expression (71%) and an increase in apoptosis (30%) were observed in the flaxseed, but not in the placebo group. No significant differences in caloric and macronutrient intake were seen between groups and between pre- and posttreatment periods. A significant increase in mean urinary lignan excretion was observed in the flaxseed group (1,300%1) compared with placebo controls. Dietary flaxseed has the potential to reduce tumor growth in patients with breast cancer.

Enterolignans (enterolactone and enterodiol) are phytoestrogens that are formed by the colonic microflora from plant lignans. They may reduce the risk of certain types of cancer and cardiovascular diseases. Initially, only secoisolariciresinol and matairesinol were considered to be enterolignan precursors, but recently, new precursors such as lariciresinol and pinoresinol were identified.

 7-hydroxymatairesinol
Linnea, the exclusive supplier of HMRlignan, announced in 2006 that new Finnish research has uncovered the naturally occurring existence of 7-hydroxymatairesinol as the dominant lignan in wheat, triticale, barley, corn, amaranth, millet and oat bran. The study entitled, “Identification of 7-hydroxymatairesinol and several other previously unidentified lignans in cereals, oilseeds and nuts--the role of extraction method,” by Smeds, AI, et al. Department of Biochemistry and Pharmacy, Abo Akademi University, details how a new analytical technique was able to reveal, for the first time, the presence of the compound 7-hydroxymatairesinol in a variety of food sources. Prior to the results of this research, the lignan was known to be found in Norway spruce (Picea abies), which still remains the most potent, and hence, economically viable source for manufacture into dietary supplements and functional foods. “The results of this study demonstrate that 7-hydroxymatairesinol is a common lignan in foods, and an important micronutrient in the human diet,” says Robin Ward, Vice President of Marketing, Linnea Inc. Derived from Norway spruce (Picea abies), HMRlignan is a direct enterolactone precursor dietary supplement. It is a proprietary and patent-protected product manufactured and marketed worldwide by Linnea, Switzerland.
   About Linnea - From its headquarters and manufacturing facility in Locarno, Switzerland, Linnea specializes in the manufacture of botanical extracts and phytochemicals, and is a leading supplier to the pharmaceutical, dietary supplement and cosmetic industries. HMRlignan™ is a proprietary, patent protected, product manufactured by Linnea SA. The company’s U.S. office, Linnea Inc., is located in Easton, Pennsylvania.

Questions
Q. In one of your articles you claim that flax seed is the richest source of lignan precursors. This, in fact, is not true. There is a new product on the market right now that contains much more. The product is called Mila (a proprietary mixture of Salvia Hispanica l.) and only 1 scoop (13grams) of Mila? provides 935 mg of Lignans. By comparison, the same serving size of flax contains approximately 33 mg of lignans. Also, Mila is 100% natural and considered a whole raw food by the FDA.  Yes, I am indeed a independent distributor, however, this is not a shameless advert but rather I wanted to clarify.
   A. Thus far I have not found any research regarding the lignan content of Mila. If you have any data on this I would be glad to review.

I notice that someone had questioned whether flax was the highest-yielding source of lignans, and was promoting “proprietary” Salvia hispanica. It is good stuff, and does have higher quantities of lignans than flax (though they haven’t been studied as well). But you might want to mention to your readers, before they go off hunting for “Mila,” the “proprietary Salvia hispanica,” that it is just chia seed. Yes, there are many breeds, just as there are many breeds of tomatoes. But there isn’t an real evidence I can find that “Mila” is superior to the chia you’d use to grow chia pets.