By: Catherine Ebeling, RN, BSN
"Fats" used to be all grouped together in one category. But this is no longer true. Fats have become a confusing array of food components including "good fats", "bad fats", saturated fats, unsaturated fats, monosaturated fats, polyunsaturated fats and on and on. Part of this big fat picture are the omega 3 fats and omega 6 fats which are a part of the polyunsaturated fat family.
By now we are well aware of the benefits of omega 3 fats, and studies show that a diet rich in omega 3 fatty acids has a number of significant health benefits, including protection and prevention of:
• Coronary heart disease
• Hypertension
• Type 2 diabetes
• Renal disease
• Rheumatoid arthritis
• Ulcerative colitis
• Crohn's disease
• Chronic obstructive pulmonary disease
• Alzheimer's disease
• ADD/ADHD
• Depression and Aggression
• Cancer
• Immune system
The interesting thing about these health findings is that it is specific components in omega 3's that protect against many of these health conditions. And all omega 3 fats are not the same.
What are the important components that make up omega 3 fats that are necessary to our good health?
Omega 3 fats can contain three primary components, depending on the source - plant or animal. Those components are Alpha Linolenic Acid or ALA, EicosaPentaeonic Acid or EPA, and DocosaHexaeonic Acid or DHA.
Plant sources of omega 3 fatty acids include flaxseed and flaxseed oil, walnuts, and greens. Plant sources of omega 3's contain mostly ALA or Alpha Linolenic Acid.
Animal sources of omega 3 fatty acids come primarily from fatty wild caught fish, grass fed meats, grass fed cheeses, butter and also eggs - especially those from true free range chickens who are allowed to eat their natural diet - and all contain primarily EPA and DHA.
What is the difference between plant sources of omega 3's and animal sources?
Well, not all omega 3's are created equal. There are long-chain and short-chain versions of omega 3's. The shorter chain versions come from the vegetable and plant sources such as walnuts, flaxseed, and leafy green vegetables.
But, the human body actually requires the long chain forms of omega 3's, like the kind that come from animal sources, so the vegetable source omega 3s are of relatively limited nutritional value, because they must be converted into a usable form of omega 3.
While some plant source omega 3's may be converted to the longer chains DHA and EPA, the process is inefficient, only about 5% to approximately 20% or so are actually converted. And, not everyone is able to do so at the same rate. This may have to do with an individual's diet and their particular ratio of omega 6 fats to omega 3 fats intake. The process of conversion also declines with age.
In order to make sufficient amounts of EPA and DHA, one needs to consume at least 5 or 6 times more plant source ALA than if you relied on grass fed meats and fatty fish.
Additionally a higher intake of omega 6 fats actually competes with this conversion of omega 3 ALA into DHA and EPA. Women actually have a slightly higher ALA conversion efficiency than men, meaning that for them, ingesting omega 3 fats from flax and other plant sources may be somewhat more beneficial for their health.
Grass fed meat, and wild caught fatty fish, on the other hand, contain little ALA, but are rich in the more easily utilized EPA and DHA. Eating animal source omega 3 fats means that your body doesn't have to work so hard converting fatty acids. Grass fed meat and wild caught fatty fish are the most accessible and concentrated source of this prized nutrient.
Omega 3 fats are essential to our health and our children's health. While plant source omega 3's are somewhat beneficial, the best source of omega 3 essential fatty acids come from grass fed meats and wild caught fatty fish such as salmon, cod, halibut, sardines, and krill.
Animal source omega 3 fats contain the two most important components, DHA and EPA that are vital to our physical, mental and emotional health. Check labels carefully if purchasing foods (especially processed foods) that claim to have extra omega 3 fats added and look at the source of that fat. Many companies claim the benefits of omega 3's, but use plant source omega 3 fats.
Now you know...it does make a difference.
Sources:
Dr. Joseph Mercola, "Flax is Not the Best Omega-3 Fat", April 3, 2002. Mercola.com.
Dr. Artemis P. Simopoulos, "Essential fatty acids in health and chronic disease", Am. J. Clinical Nutrition, September 1999; 70: 560 - 569
Burr, G.O., Burr, M.M. and Miller, E. "On the nature and role of the fatty acids essential in nutrition" J. Biol. Chem. 86 (587). http://www.jbc.org/cgi/reprint/97/1/1.pdf.
Gerster H, "Can adults adequately convert alpha-linolenic acid to eicosapentaenoic acid and docosahexaenoic acid?". Int. J. Vitam. Nutr. Res. 68 (3): 159-173.
Brenna JT ,"Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man.". Curr. Opin. Clin. Nutr. Metab. Care 5 (2): 127-132. March 2002.
Burdge GC, Calder PC, "Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults.". Reprod. Nutr. Dev. 45 (5): 581-597.