NEW STUDY DISCREDITS FAULTY BMJ STUDY ON OMEGA-3 FATTY ACIDS AND PROPOSES NEW RISK FACTOR FOR HEART DISEASE

By Greg Arnold, DC, CSCS, September 6, 2006, abstracted from “Cardiovascular benefits of omega-3 fatty acids” published online ahead of print in Cardiovascular Research

Perhaps no other supplement has been touted to benefit the heart more than omega-3 fatty acids (O3FA).  With a health claim issued by the Food & Drug Administration finding “consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease” (1), research seemed to be nearly bulletproof that omega-3 fatty acids significantly benefited the heart.

But a study released by the British Medical Journal on April 1, 2006 (2) suggesting that omega-3 fatty acids “do not have a clear effect on total mortality, combined cardiovascular events, or cancer” momentarily cast doubt as to the heart-healthy benefits of O3FA’s.  Fortunately, scientific authorities quickly pointed out the many faults of the study (3, 4).  

Now a new study (5) has confirmed the significant benefits of omega-3 fatty acids, and researchers have proposed a new risk factor for heart health called the omega-3 index.

In the study, researchers discussed the current recommendations of one gram per day of fish oil “for cardiovascular disease prevention, treatment after a myocardial infarction, prevention of sudden death, and secondary prevention of cardiovascular disease”.  They then went on to call the recent British Medical Journal study “methodologically questionable” and cited the four large trials that all supported the one gram per day recommendation (6,7,8,9).

But they went a step further and proposed a new risk factor for heart health called the omega-3 index.  Measured in red blood cells and expressed as a percentage of EPA + DHA (the 2 omega-3 fatty acids found in fish oil) of total fatty acids, they state that an omega-3 index of less than 8% is associated with a 90% decreased risk for sudden cardiac death compared to an omega-3 index of less than 4%.

They go on to state that the omega-3 index “has striking similarities to LDL as a risk factor for coronary artery disease” and is similar to using HbA1c as a risk factor for type 2 diabetes (10).

Whether or not the American Heart Association, European Journal of Cardiology and other national cardiac societies will adopt the omega-3 index as a risk factor for heart disease remains to be seen.  But what has been hopefully put to rest is the question of whether or not omega-3 fatty acids benefit heart health.

Greg Arnold is a Chiropractic Physician practicing in Danville, CA.  You can contact Dr. Arnold directly by emailing him at mailto:ChiroDocPSUalum@msn.com or visiting his website

www.CompleteChiropracticHealthcare.com

References:

1. “Letter Responding to Health Claim Petition dated November 3, 2003: Omega-3 Fatty Acids and Reduced Risk of Coronary Heart Disease” from the U.S. Food and Drug Administration Website http://www.fda.gov/bbs/topics/news/2004/NEW01115.html
2. Hooper L.  Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review.  BMJ 2006; 0: bmj.38755.366331.2Fv1
3. Johanna M Geleijnse.  Risks and benefits of omega 3 fats: Health benefits of omega 3 fats are in doubt.  BMJ, Apr 2006; 332: 915; doi:10.1136/bmj.332.7546.915
4. Twisselmann B.  Risks and benefits of omega 3 fats: Summary of responses.  BMJ, Apr 2006; 332: 915 - 916 ; doi:10.1136/bmj.332.7546.915-b
5. Von Schacky C.  Cardiovascular benefits of omega-3 fatty acids.  Card Res 2006. In Press, Accepted Manuscript, Available online 1 September 2006
6. von Schacky C. The role of omega-3 fatty acids in cardiovascular disease. Curr Atheroscler Rep 2003;5:139-45
7. Harris WS. Extending the cardiovascular benefits of omega-3 Fatty acids. Curr Atheroscler Rep 2005;7:375-80
8. Albright J, et al. Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. J Am Med Assoc 1995; 275:836-7
9. Ma J.  Blood levels of long-chain n-3 fatty acids and the risk of sudden cardiac death. N Engl J Med 2002;346:1113-8
10. Khaw, K.T., et al., Glycated haemoglobin, diabetes, and mortality in men in Norfolk cohort of european prospective investigation of cancer and nutrition (EPIC-Norfolk). Bmj, 2001. 322(7277): p. 15-8.