The promising evidence surrounding the dietary benefits of consuming food with high lignan content revolves around the low incidence of breast, colon and prostate cancers found with those people who regularly eat food with high lignan content. Research findings are concluding that the chemical release of these plant hormones in the body, are able to block the action of certain cancer-causing substances.

Researchers believe these plant hormones mimic the body’s own estrogen type of cells and can block the formation of hormone-based tumors or growths. Unlike the hormones produced in the body, these plant hormones do not stimulate cancerous cells to grow. In fact, lignans boost production of a substance that fastens onto human estrogen and carries it out of the body. They are also considered to be anti-oxidants; therefore, researchers believe lignans can protect healthy cells from cancer causing agents known as free radicals. Research findings continue to show promise in this area.

Flax seed is certainly considered to be a veritable storehouse of lignans when compared with other foods. Many plant foods have some lignans, yet flax seed has proven to be the super-food in this area, with boasting anywhere from 75 to 800 times the amount of lignan content as other grain and vegetable sources. In fact, to get the lignans that are in just 1/8 cup of flax seed, you would need to eat about 60 cups of fresh broccoli, or 100 slices of whole-wheat bread.

Our unique mechanical process has produced an amazing Concentrated Flax Hull Lignan product. The result is 90% natural pure flax hulls yielding the highest concentration of SDG lignans available in the world. These flax hulls contain about 45-60 mg of SDG per gram of finished product. This is approximately 7-8 times more concentrated than ground flaxseed, is shelf stable, therefore more effective than flax seed alone. Our competitors cannot come close to the concentration of flax hull lignans that are found in our lignan product.

Other sources of lignans such as rye, buckwheat, millet, soy, and barley, yield 2-5 micrograms of lignans per gram (mcg/g) of grain. Flaxseed yields an extraordinary 800 mcg/g of lignans.

Lignans were first discovered in flaxseeds in the mid 1950's. The first interests in SDG's arose in the mid 1980's. The lignan compounds have shown such extraordinary potential that they have been studied by the National Cancer Institute for their cancer preventative properties. The SDG lignan not only has anti-cancer properties, it has anti-viral, anti-bacterial, and anti-fungal properties. It is also a powerful anti-oxidant. Most of the SDG’s tested for their anti-oxidant activity have shown themselves to be 5 times greater in activity than Vitamin E.

Other Lignan Products

Products claiming "High Lignan Flax Seed Oil" tested by the University of North Dakota have been found to contain practically no lignans at all. That is expected because the lignans are not in the oil; they are in the hull of the seed.

"20% lignan particulates" does not mean it contains 20% lignans, but it means 20% of the product is made up of pieces of the flax fiber shell which does contain the lignans. Since fiber meal contains 1.6% lignans, such a product would contain about 0.35% lignans. If the product is a liquid these particles will settle to the bottom and no lignans will be consumed until you are the end of the bottle unless it is always shaken well before it is poured.

Another product says "up to 30% more lignans than the whole flax seed." This is essentially a product consisting mostly of the defatted flax fiber without the oil. There is no concentration or extract of lignans. Such a product would thus contain about 1.5% lignans, which was the highest level of lignans available until recently.

1. Adlercreutz H., et al. "Excretion of the lignans enterolactone and enterodiol and of equol in omnivorous and vegetarian postmenopausal women and in women with breast cancer"

2. Bakke, J.E., and H.J. Kloesterman, "A new diglucoside from flaxseed". Proceedings of the North Dakota Academy of Science, 1956; 10:1 8-22

3. Adlercreutz, H., Mazur, W. "Phyto-estrogens and Western Diseases" Ann. Med., 19897,29(2):95-120 Prasad, K.

4: "Antioxidant Activity of Secoisolariciresinol Diglycoside derived Metabolites, Secoisolariciresinol, Enterodiol, and Enterolactone" Int. Journal of Oncology, 2000 Oct. 9:220-225

Flaxseed and Cancer Cells

In vitro (test tube) and animal studies have suggested that the lignans in flaxseed may reduce breast carcinogenesis and metastasis (ability of cancer cells to migrate to other parts of the body) (1, 2). Women who develop breast cancer generally have a 10-20% higher concentration of the estrogen hormone estradiol (3). This suggests that the reported anti-estrogenic activity of flaxseed-derived lignans may be health protective in women who have high circulating levels of this hormone. Also, it has been suggested that a high intake of dietary fiber, such as that found in flaxseed, may reduce the risk of cancer by increasing the excretion of carcinogenic bile salts from the colon (4). A randomized, controlled clinical trial of 10g/day ground flaxseed in postmenopausal women showed an increase of the urinary ratio of 2-hydroxyestrogen (2-OH) to 16-á-hydroxyestrogen (16-á-OH) estrogen metabolites, as well as an increase in 2-OH metabolites alone; both of these ratio alterations are considered to be protective against breast cancer (5). Another randomized controlled clinical trial reported a significant, dose-dependent reduction of serum 17â-estradiol in postmenopausal women who supplemented with 5-10 grams per day of flaxseed (3). Since epidemiological studies show approximately 10% increases in 17â-estradiol in breast cancer patients, these findings may indicate a protective effect (3).

When flaxseeds are consumed, their plant lignans, secoisolariciresinol diglycoside (SDG) and matairesinol diglycoside (MDG), are converted in the body to the mammalian lignans, enterodiol and enterolactone; women with a history of breast cancer have significantly lower levels of enterodiol and enterolactone than women without cancer (6, 7). Additionally, lignans can exert anti-estrogenic effects when circulating levels of estrogen are raised, and lifetime estrogen exposure has been linked to risk of breast cancer. The combination of these findings suggests that plant lignans may reduce the risk of estrogen-related breast cancer (6, 7). In addition to the effects of lignans, the fiber found in flaxseeds may help to remove estrogen, as well as other potentially carcinogenic compounds, from the body (8, 4).

Clinical research has suggested that flaxseeds may beneficially alter levels of compounds that are used as markers for risk of breast cancer development. An increased ratio of the estrogen metabolites 2-hydroxyestrogen (2-OH) to 16-alpha-hydroxyestrogen (16-á-OH) has been suggested to be preventive against breast cancer. In clinical trials, 5-10 grams of daily ground flaxseed consumption has been shown to increase the 2-OH: 16-á-OH ratio (8, 5. High levels of serum17â-estradiol may be another biomarker for increased breast cancer risk, as epidemiological studies have shown an approximately 10% increase in serum 17â-estradiol in breast cancer patients; a randomized, controlled, clinical trial in postmenopausal women supplemented with 5-10 grams per day of ground flaxseed for 7 weeks reported a significant, dose-dependent reduction of serum 17â-estradiol (7).

Flaxseeds have also been beneficial in treating breast cancer in animals. A reduction in breast tumor growth, as well as reductions in levels of compounds involved in tumor growth and metastasis (cancer cells spreading throughout the body), have been shown to occur after supplementing with flaxseeds and/or plant lignan extracts (2, 9). Additionally, breast cancer cells treated with purified enterodiol and enterolactone have been shown to have a reduced ability to metastasize (1). This effect of flaxseed is similar to that of the breast cancer drug, Tamoxifen. The positive effects of flaxseed in these studies have been shown both in breast cancers that express estrogen receptors and in those that do not, suggesting that these effects may be mediated through estrogen-like lignan activity and also by some other, still to be determined, physiological mechanism.(1).

The information presented here is for informative and educational purposes only and is not intended as curative or prescriptive advice.

Bibliography

1. Chen J, Thompson LU. Lignans and tamoxifen, alone or in combination, reduce human breast cancer cell adhesion, invasion and migration in vitro. Breast Cancer Res Treat 2003;80(2):163-70.

2. Dabrosin C, Chen J, Wang L, Thompson LU. Flaxseed inhibits metastasis and decreases extracellular vascular endothelial growth factor in human breast cancer xenografts. Cancer Lett 2002;185(1):31-7.

3. Hutchins AM, Martini MC, Olson BA, Thomas W, Slavin JL. Flaxseed consumption influences endogenous hormone concentrations in postmenopausal women. Nutr Cancer 2001;39(1):58-65.

4. Adlercreutz H. Does fiber-rich food containing animal lignan precursors protect against both colon and breast cancer? An extension of the "fiber hypothesis". Gastroenterology 1984; 86(4):761-4.

5. Haggans CJ, Hutchins AM, Olson BA, Thomas W, Martini, MC, Slavin JL. Effect of flaxseed consumption on urinary estrogen metabolites in postmenopausal women. Nutr Cancer 1999; 33(2):188-95.

6. Adlercreutz H, Fotsis T, Heikkinen R, Dwyer JT, Woods M, Goldin BR et al. Excretion of the lignans enterolactone and enterodiol and of equol in omnivorous and vegetarian postmenopausal women and in women with breast cancer. Lancet 1982;2(8311):1295-9.

7. 58-65.

8. Haggans CJ, Travelli EJ, Thomas W, Martini MC, Slavin JL. The effect of flaxseed and wheat bran consumption on urinary estrogen metabolites in premenopausal women. Cancer Epidemiol Biomarkers Prev 2000;9(7):719-25.

9. Thompson LU, Rickard SE, Orcheson LJ, Seidl MM. Flaxseed and its lignan and oil components reduce mammary tumor growth at a late stage of carcinogenesis. Carcinogenesis 1996;17(6):1373-6.