Lignans

Lignans are a group of chemical compounds found in plants. Lignans are one of the major classes of phytoestrogens, which are estrogen-like chemicals and also act as antioxidants. The other classes of phytoestrogens are the Isoflavones and coumestans.

Special Precautions of Lignans

• Lignan precursors in foods are not known to have any adverse effects.
• Flaxseeds, which are rich in lignan precursors as well as fiber, may increase stool frequency or cause diarrhea in doses of 45-50 g/day in adults.
• The University of Maryland Medical Center recommends speaking to your doctor before increasing your phytoestrogen intake if you have any hormone-related conditions, such as ovarian cancer, uterine fibroids, endometriosis or pregnancy. Phytoestrogens have the potential to negatively affect these conditions.
• The safety of lignan supplements in pregnant or lactating women has not been established. Therefore, lignan supplements should be avoided by women who are pregnant, breast-feeding, or trying to conceive.

The benefits of Lignans are

• Anticancer – Various studies have found an association between higher intake of plant lignans and a reduced risk of breast, endometrial, ovarian and prostate cancers.
• Studies show that breast cancer is lower in countries where the intake of phytoestrogens is high...implying that these compounds may reduce breast cancer risk," says Dr. Velentzis. "Isoflavones and lignans are the most common phytoestrogens in the diet." Dr. Velentzis says your best way to fight breast cancer is to increase your lignan intake.
• Heart health – Diets rich in plant foods have consistently been shown to help reduce your risk of cardiovascular disease. Research suggests that lignans are one of the many nutrients and phytochemicals in plants that contribute to their cardioprotective effects.
• Weight control – A 2009 study of postmenopausal women showed that those who had a higher dietary lignan intake also had less body fat and lower blood sugar levels.
• Lignans are also good antioxidants scavenging free radicals that may play a role in some diseases.

Food sources

Lignans are found in many foods. And researchers at Oregon State University (OSU) offer some guidance on the best places to get them. They say the best source is often found in seeds. You can find it in rich quantities in pumpkin seeds, poppy, flaxseed and sunflower seeds. The next best source is found in vegetables including broccoli, kale, cabbage and Brussels sprouts. Or...if you prefer fruit...you can also get rich quantities in strawberries and apricots. Flaxseed and Sesame Seeds contain higher levels of lignans than most other foods. The principal lignan precursor found in flaxseed is secoisolariciresinol diglucoside. Other sources of lignans include cereals (rye, wheat, oat and barley - rye being the richest source), soybeans, Cruciferous Vegetables such as broccoli and cabbage, and some fruits, particularly apricots and strawberries.
Secoisolariciresinol and matairesinol were the first plant lignans identified in foods. Pinoresinol and lariciresinol are more recently identified plant lignans that contribute substantially to the total dietary lignan intakes. Typically, Lariciresinol and pinoresinol contribute about 75% to the total lignan intake whereas secoisolariciresinol and matairesinol contribute only about 25%.This distribution may change as the contributions of syringaresinol and hydroxymatairesinol have not properly been quantified in foods. If your diet primarily consists of unrefined, high-fiber plant foods, you’re likely getting a good amount of lignans. It’s recommended you get 23-30 grams of fiber per day to provide an optimal amount of plant lignans. Although, very few people on a Western diet actually eat this amount of fiber. In the United States, the average daily intake of fiber is only 15 grams. Another issue that may affect your uptake of lignans is digestive health. If your digestion is impaired for any reason, you may not be breaking down the lignans you eat well enough to convert them into phytoestrogens. Healing your gut will help with this situation.

Sources of lignans:

Source	Amount per 100 g
Flaxseed	300,000 µg (0.3 g)
Sesame Seeds	29,000 µg (29 mg)
Brassica vegetables	185 - 2321 µg
Grains	7 - 764 µg
Red Wine	91 µg