Whole Flaxseed: More Health Benefits Than Oil

by Ed Blonz, Ph.D. | The Charlotte Observer | 03.28.2006

Q. In response to an inquiry on flaxseed in a recent column, you suggested a Canadian Web site for more information. I started there and continued on to a few other sites. I then bought some flaxseed, ground it with my coffee grinder, and have been adding it to my diet on a daily basis. I still have two questions that I have not been able to find definitive answers to and was hoping that you might be able to help. First, what is the recommended daily amount for a healthy 53-year-old male? I found anything from 1 tablespoon to 3 tablespoons as a guideline. I want to take enough to get the benefits without taking too much. More importantly, a physician reported on a Web site that men should avoid flaxseed, based on a University of Virginia Medical School study that found that "flax seed oil may promote the growth of prostate tumors in someone with prostate cancer." Is this a concern? Does it apply to ground flaxseed? Is the risk worth the health benefits? Any information that you can offer would be greatly appreciated. Thank you.

It is important to appreciate that fats and oils represent nature's most concentrated source of energy. It is the storage material of choice in the plant world, ideal when there is a need to pack a lot of energy into a small space. The seed is the prime example, as it can be light in weight and small in size yet contain sufficient fat energy to fuel growth until the seed sprouts and the plant is ready to make energy on its own.

Plants have various types of protection to make sure the fat remains viable when needed. One technique in nature is to encase the fat in its own protective compartment. Perhaps more important for our purposes, however, is the way that plants tend to produce protective substances to help ensure that the needed fats will be undamaged and available as a fuel for the seed.

Flaxseed oil is highly unsaturated; about 60 percent of the fatty acids in flax are polyunsaturated. Of concern with prostate cancer is alpha-linolenic acid, an omega-3 polyunsaturated fatty acid that is plentiful in flax. A study in the July 2004 edition of the American Journal of Clinical Nutrition found a significant relationship between the intake of ALA and the risk of prostate cancer. By contrast, EPA and DHA, omega-3 fatty acids found in fish, were associated with a protective effect.

When flaxseed oil is removed from the seed and separated from its phytochemical bodyguards, the chances of the oil breaking down and causing health problems increases. With whole flaxseed, you get the entire package of fats, fiber and the variety of phytochemical compounds and antioxidants, known as lignans, that are present naturally in flax. These are not normally present in flaxseed oil. Whole flaxseed has not been associated with an increased risk of cancer. In fact, there is evidence that this whole food has cancer-fighting abilities.

The message here is that we need to make sure that the fats we eat are well protected by having them as a part of a whole food. Then we can be sure to have the greens, vegetables and fruits that bring along their own variety of healthful components.

When eating flaxseed, cracking or grinding makes sense, as the fibrous protective coats of intact seeds tend to pass through undigested. One tablespoon of ground flaxseed contains about 1.6 grams of omega-3 fatty acids, which is in the range recommended for adults by the Institute of Medicine. (If not used immediately, ground flaxseed should be refrigerated and sealed tightly.)

In the end, if you have concerns about prostate cancer or any other cancer, be sure to discuss your choices with your physician or the dietitian with whom you doctor works.

Copyright 2006 The Charlotte Observer