The Health Benefits of Lignans

by Aviva Natural Health Solutions August 17, 2009

Dr. Kristie Leong

There's more and more evidence emerging that compounds found in plants play a role in disease prevention. The natural chemicals that plants produce to protect themselves against bacteria, fungi, and direct sunlight have been shown to have benefits in humans by acting as anti-oxidants, anti-inflammatories, and immune stimulators. Among the thousands of phytonutrients already described is a type of chemical compound found in known as lignans. What are the benefits of lignans and why do you need more of them in your diet?

Lignans are natural plant chemicals that are classified as phytoestrogens, meaning they have weak estrogen-like effects in the human body. When they bind to estrogen receptors, they don't stimulate the receptor as much as the stronger estrogens produced by the ovaries. At the same time when they bind, they block the effects of more potent estrogens which is a good thing when it comes to the risk of hormonally dependent cancers.

One area where the health benefits of lignans has received a great deal of attention relates to breast health. When foods rich in lignans are eaten, they're broken down into other lignans by the bacteria in the gut. Once broken down, they enter the circulation. Because they have a structure similar to estrogen, they have a natural affinity for estrogen receptors on the breasts, yet they don't stimulate breast cells as much as natural estrogen. Because breast cells aren't stimulated to grow by these natural phytoestrogens, there's less risk of developing a cancer.

This all sounds good in a theoretical sense, but are the health benefits of lignans real? One study showed a fifty-eight percent reduction in breast cancer risk associated with intake of lignan rich foods. Another study showed that a lignan rich diet reduced mortality in postmenopausal women diagnosed with breast cancer by seventy percent, although it had little effect on premenopausal breast cancer survival. Postmenopausal women who ate the highest levels of lignans also had their overall risk of mortality cut in half, suggesting that lignans have some protective effect against cardiovascular disease too. Other health benefits of lignans include the potential to reduce the risk of prostate cancer which has shown promise in animal studies.

To get the health benefits of lignans, what do you need to eat? One of the best sources is flaxseed, although it needs to be ground to be digested. The seeds have a tough surface covering that needs to be penetrated in order to release the lignans. Ground flaxseed can be added to cereals, salads, and soups. Other good sources are sesame seeds and cruciferous vegetables such as broccoli and cauliflower.

The bottom line? There is some evidence supporting the health benefits of lignans, although larger, randomized clinical trials are needed. Until then, it's safe for most people to add ground flaxseed to their diet. Most sources recommend two tablespoons a day which also provides a health dose of fiber. Talk to your doctor if you have a history of breast or prostate cancer before adding lignans to your diet.