Thursday, October 28, 2010

Is Flaxseed Oil Heart-Healthy?

Question: Do you believe flaxseed oil helps the heart? My husband was on fish oil and had four stents placed in his heart. In six months, two of the stents were closing. He started on flaxseed oil, and the stents cleared within six months. We've remained on flaxseed oil (high-lignan, cold-pressed, organic) for nine years and the heart has remained stable.

Dr. Hibberd's Answer:

Flaxseed oil is heart healthy, but our current data emphasizes the superiority of fish sources of omega-3. Flaxseed oil contains omega-3 fatty acids in the form of ALA. ALA has to be converted by the body to produce EPA and DHA. Fish oil contains DHA and EPA.

There is no longer any debate that omega-3 fatty acids are cardio-protective. We now have a prescription version of omega-3 supplements intended for cardiac and at-risk patients that increases HDL (good) cholesterol by up to 9 percent and decreases triglycerides (bad fats) by up to 45 percent but has an overall neutral effect on the LDL (bad) cholesterol.

The debate between flaxseed oil and fish oil begins with the fact that there are three main types of omega-3 fatty acids: DHA, EPA, and ALA. They are similar in structure, but each has different benefits.

Our bodies need DHA. Our brain needs DHA. DHA provides us with the vascular protection seen with omega-3 supplementation. Fish products provide EPA and DHA without requiring metabolic conversion that is so often interrupted by elements of our modern diets. You will find that although ALA is a precursor for EPA, its necessary transformation to EPA and then to the beneficial DHA has many roadblocks.

Fish is the preferred source of DHA simply because it is readily bio-available without multiple steps of metabolic conversion that are often inefficient and inadvertently blocked by our diets or other supplements we might take.

Our bodies will usually convert large amounts of ALA (alpha-linoleic acid) rapidly into smaller amounts of EPA (eicosapentaenoic acid), and then our bodies will in turn convert this into even smaller amounts of protective DHA (docosahexaenoic acid). These conversion steps will be slowed, and in some cases minimized, by certain foods and additives in our diets.

Most hydrogenated oils contain trans-fatty acids (seen in margarines, chips, cookies, popcorn). Diets rich in these will interrupt or eliminate the ALA to EPA to DHA conversion, reducing the full potential benefit.

We also need the correct balance of omega-3 to omega-6 fatty acids. For the typical person, we recommend a ration of two to four times more omega-6 fatty acids to the amount of omega-3 fatty acids in our diet. Too much omega-6 also reduces and may block the conversion of ALA to DHA and EPA.

Unfortunately, most of our diets have 15 to 25 times more omega-6 fatty acids than omega-3 fatty acids because of the prevalence of vegetable oils such as sunflower and corn oil. As you can see, this also cuts down on the conversion from ALA to EPA and DHA. You will need 11 grams of ALA to produce one gram of EPA and DHA, without considering the negative effect other items in your diet may have on this conversion.

In summary: Eat cold-water fish two to three times a week. Fish is a very good source of protein and omega-3 fatty acids. Fish oil may not be the best supplement unless you are careful with its purity.

Be alert that all fish oil products are not the same. Some may have additional unwanted toxins, especially if sources are known to have higher levels of mercury or other toxins. This happens most often when they do not come from a cold-water source. In addition, some fish oils come from the by-products of the processed fish meal which has often been oxidized by the heat and air exposure of the fish-processing process, in some cases making it rancid. Consumer beware!

Also, Infants and small children should generally not use fish oil supplements, especially cod liver oil. Cod liver oil should be avoided as a source of omega-3 fatty acids because fish-liver oil contains toxic amounts of vitamin A at the higher dosages.

Foods high in ALA (walnuts and flaxseed oil) are useful adjuncts for anyone desiring a healthy diet, and may be consumed in conjunction with a diet containing cold-water fish and/or well-standardized prescription-grade fish oil supplements.

It sounds like your husband has a combination that is palatable to him, and any changes are best probably made in consultation with his cardiologist. Most of us should probably follow the recommended guidelines of adding omega-3 in the form of fish products or supplements to achieve maximum protection.

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