Since starting this blog last year I have often mentioned the omega 3 fatty acids and explained how they are vital for our health. Research suggests that these essential fats play a role in the prevention of several diseases ranging from heart disease to cancer, stroke, diabetes, arthritis, asthma, osteoporosis, mood disorders (including depression), eye diseases and many more, including most conditions with a link to inflammation.
In June I wrote about the importance of fatty acids for health and discussed how the typical western diets now are completely different from the diets of our ancestors and how our intakes of the essential omega 3 fats are generally considered to be too low by many scientists.
A very recent study (1) reviewed the evidence for the importance of omega 3 fatty acids for prevention of cardiovascular disease (heart disease and stroke). The results confirm that omega 3 fats are important in preventing primary cardiovascular disease i.e. preventing cardiovascular diseases in healthy individuals, as well as secondary cardiovascular disease i.e. cardiac events and mortality in patients with existing heart disease. The authors of the study say that the most compelling evidence for omega 3 fats in cardiovascular disease comes from 4 well designed controlled trials of almost 40,000 participants. In the trials the long chain omega 3 fat eicosapentaenoic acid (EPA) was used with or without docosahexaenoic acid (DHA), another long chain omega 3 fatty acid (1).
EPA and DHA are the long chain omega 3 fatty acids found most abundantly in oily fish such as mackerel, salmon, trout and herring. They are also found in much smaller amounts in algae. The shorter chain omega 3 fatty acid alpha-linolenic is found most abundantly in flaxseeds and walnuts, the body can bioconvert this short chain omega 3 into the longer chain forms but the process is inefficient. Taking in EPA and DHA in their long chain forms is a much more reliable way of providing these long chain fats to the body.
The authors of the review study (1) say that individuals without cardiovascular disease should aim to have an EPA and DHA intake of at least 500mg per day and people with known coronary heart disease should get at least 800mg-1000mg of these fatty acids per day. The authors conclude that “Further studies are needed to determine optimal dosing and the relative ratio of DHA and EPA -3 PUFA that provides maximal cardioprotection in those at risk of cardiovascular disease as well in the treatment of atherosclerotic, arrhythmic, and primary myocardial disorders”.
In a press release (2) the lead author said: “This isn’t just hype; we now have tremendous and compelling evidence from very large studies, some dating back 20 and 30 years, that demonstrate the protective benefits of omega-3 fish oil in multiple aspects of preventive cardiology”
It is thought that the long chain omega 3 fats, EPA and DHA, work by incorporating into cell membranes. This in turn may be helping to improve the heart’s electrical activity, vascular tone and blood pressure. The long chain fats also act as anti-inflammatory agents in the body. Cardiovascular disease is considered to be an inflammatory condition.
The results of this(1) and other studies suggest that eating 2-4 portions of oily fish is advisable for health. If you do not eat oily fish regularly you may wish to seriously consider a fish oil supplement that provides 250-350mg of EPA and 250-350mg DHA daily. There are now vegan and vegetarian EPA and DHA supplements available that are produced from algae. They are quite expensive and have not yet been used in clinical trials but may well be worth taking since vegans and vegetarians are often lacking in omega 3 fats. Flaxseed oil providing 500-1000mg alpha-linolenic acid a day can also be considered. The body can convert this into EPA and DHA, as I have said before the process is not efficient, however some preliminary studies have shown that alpha-linolenic acid may also have heart protective effects.
(1)Lavie CJ et al. 2009. Omega-3 Polyunsaturated Fatty Acids and Cardiovascular Diseases. J Am Coll Cardiol, 2009; 54:585-594
(2) http://www.sciencedaily.com/releases/2009/08/090803173250.htm. American College of Cardiology (2009, August 3). Mounting Evidence Of Fish Oil’s Heart Health Benefits. ScienceDaily. Retrieved August 4, 2009, from http://www.sciencedaily.com¬ /releases/2009/08/090803173250.htm
Written by Ani Kowal