The benefits of flaxseed have been described for decades. Flaxseed has a very hard husk and contains several oils. If you eat flaxseeds whole, they will pass through undigested. In practice, the seed is crushed and the oil is harvested. Fish oil is a better source of DHA and EPA, and unless you are allergic to fish, they are the better source. The most important component of the flaxseed is the husk. It is rich in lignin, which has the unique property of binding toxic substances, such as LDL cholesterol and lipoprotein-a, reducing atherosclerotic heart disease, and through a different mechanism, reducing prostate and breast cancer. Many patients with years of irritable bowel syndrome have found relief with milled flax.
The way to maximize lignan exposure is to mill the flaxseed. How one mills can make a significant difference. Historically, the milled seeds contained about 10% to 15% oil, were purchased fresh, and then sold refrigerated or freeze-dried, and kept refrigerated until consumed. Left on the counter, exposed to sun and air, milled flaxseed becomes rancid in 2 to 3 weeks.
I recently found milled flaxseed that doesn’t require refrigeration. It has 5 to 7% oil content and neither smells or tastes like it’s forebear. Researching the topic, I discovered there are four ways to commercially mill flaxseed. More intense milling results in higher temperatures, smaller particles, and more oil extraction. No one has published an article comparing how this processing affects the binding capacity of hot-milled flax, but I think agricultural science has again found a way to produce a less nutritious product from a better one.
Until I see evidence that this new flaxseed is superior to the old, I would advise sticking with the old. Colder milled flax is proven to reduce cholesterol, LDL cholesterol, lipoprotein a, and block receptors that are implicated in prostate and breast cancer. It is the only substance known to bind lipoprotein-a, which the American Heart Association has declared to be a significant independent risk for heart disease. Since I found the suspect flaxseed at Whole Foods, I can only advise you to read labels carefully. Otherwise, Swanson Vitamins has an inexpensive freeze-dried milled flaxseed.