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By David Blyweiss, M.D.
By now, I’m sure you are all aware of the benefits omega-3 fatty acids provide. But, just to recap, these healthy fats promote healthy brains and hearts, fewer cardiac arrhythmias, reduced joint pain and glowing skin. They can also boost your mood, lower inflammation and slash triglyceride levels. Best of all, these multi-tasking fats are readily available in significant concentration in fatty fish, and flaxseed. But which source is best?
While both are excellent sources of omega-3s, they are not created equal. Omega-3s are actually made up of three types of fatty acids that are quite different from each other. Two are found in fish and one in flax, and they each behave differently in the body.
Flaxseeds and flaxseed oil contain an omega-3 called alpha-linolenic acid (ALA). Fish and fish oil contain two very different omega-3s, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The vast majority of the research on the health benefits of omega-3s has been done on DHA and EPA. They are the true superstars in the world of omega-3s. The health benefits of ALA are less clear, although a large randomized dietary intervention study called the Alpha Omega Trial is currently testing the effects of ALA and EPA/DHA on heart disease.
Even though the results of this trial won’t be in until late 2010, here’s what we do know about ALA and flaxseed oil: The body can convert the ALA in flaxseed into the more “valuable” fatty acids, DHA and EPA. It does this by the action of enzymes known as elongases and desaturases. But the big question is how much actually gets converted. The answer—not much.
The general consensus is that only about nine percent of ALA is actually converted into the more potent types of omega-3s. This is important because DHA is one of the most important fats for the brain, making up to two thirds of it. Both EPA and DHA keep cell membranes fluid, which is one of the reasons that fish oil—which contains both EPA and DHA—is so protective of the heart.
This can be a real dilemma for vegetarians who typically consume far more omega-6 fatty acids than omega-3s. A vegetarian who is getting all of their omega-3s from plant foods or flaxseed oil should be very careful to reduce the amount of omega-6 fats in their diet while boosting the amount of flaxseed oil they consume. A healthy and realistic ratio of omega-6s to omega-3s in the human diet is about 4:1 (the ideal is actually 1:1). The problem is that most Americans consume a ratio of around 20:1 or higher.
Since omega-6s are pro-inflammatory and omega-3s are anti-inflammatory, this ratio isn’t healthy—whether you are a vegetarian or not.
That said, flaxseed oil still has valuable properties of its own. Flax contains plant chemicals called lignans, which have profound anticancer effects.
Taking one tablespoons of whole or ground flaxseeds daily has also been proven effective for maintaining regularity and lowering cholesterol. Studies also suggest that the oil may help ease the symptoms of BPH. But if you are thinking of replacing fish oil with flaxseed oil for brain or heart health, don’t bother. It just won’t have the same effect.
To get the most benefit from your omega-3s, I recommend taking 3 to 4 grams of a high quality fish oil supplement every day in divided doses. To help prevent the fish oil from repeating, store them in the freezer and take them with a meal. But don’t stop there. It’s also smart to add fish to your diet at least twice a week. Just make sure you choose a variety of fish that is rich in omega-3s like salmon, tuna, sardines, anchovies, halibut or herring.
References:
Barden AE. Flaxseed oil supplementation increases plasma F1-phytoprostanes in healthy men. Journal of Nutrition. 2009;139:1890-1895.
Wall R. Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids. Nutrition Review. 2010;68:280-289.
Young GS. Effect of randomized supplementation with high dose olive, flax or fish oil on serum phospholipid fatty acid levels in adults with attention deficit hyperactivity disorder. Reproduction, Nutrition, Development. 2005 Sep-Oct;45(5):549-58. |
