Omega-3s & Heart Rhythms

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Omega-3 May Deter Common Heart-Rhythm Disorder

 

Study in Finnish men indicates that DHA - one of the two the long-chain

omega-3s in fish fat - may help prevent the most common cardiac

arrhythmia

by Craig Weatherby

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Atrial fibrillation (AF) is the most common cardiac arrhythmia (abnormal

heart rhythm), with more than 2.3 million people affected in the U.S. It

involves fibrillating (i.e., quivering) in the muscles of the two upper

chambers (atria) of the heart. AF is a symptom of underlying heart

disease. It often becomes a chronic condition that may result in stroke,

palpitations, fainting, chest pain, or congestive heart failure, and it

leads to a small increase in the risk of death. This cardiac condition

can be treated with drugs ... but they sometimes exacerbate AF or

produce other cardiac arrhythmias. Key Points

- Study links higher omega-3 blood levels to reduced risk of developing

atrial fibrillation (AF): a condition associated with stroke and heart

disease.

- Finnish scientists analysis found that of the two omega-3s in fish

fat, only DHA was associated with reduced AF risk.

- Prior studies are mixed with regard to omega-3 effects on AF; more

research is needed.

  Accordingly, researchers have been looking for ways to prevent AF

from developing in the first place. In some but not all studies, regular

fish consumption has been shown to reduce the risk of AF. (For a fuller

exploration of the evidence, see Omega-3s Yield Heart-Saving Effects

Even in Small Amounts [

http://newsletter.vitalchoice.com/e_article000591823.cfm?x=b7rlyJy,b1pTrCB7,w

and Fish Oil Cant Rescue the Sickest Cardiac Patients Heart Rhythms [

http://newsletter.vitalchoice.com/e_article000609253.cfm?x=b7Cr9j7,b1kJpvRw,w

..) Its been presumed that omega-3s are why eating fish seems to

reduce the risk of cardiac arrhythmias, and there are sound

physiological reasons why that makes sense. Among other possible

effects, omega-3s selectively quiet hyper-excitable heart muscle cells,

which tend to trigger arrhythmias. An epidemiological study from Finland

supports the value of fish fat, and singles out one omega-3 fat in

particular DHA as being the most beneficial. Finnish study links higher

omega-3 DHA blood levels to reduced AF riskResearchers from the

University of Kuopio in Finland wanted to look for any associations

between omega-3 blood levels and the risk of AF (Virtanen JK et al.

2009). They analyzed blood test data and medical records from 2,174 men

aged 42 to 60 who participated in the Kuopio Ischemic Heart Disease Risk

Factor Study from 1984 to 1989. All of the men were free of AF at the

start of the study, and provided blood samples upon their enrollment.

The researchers examined the mens medical records an average of almost

18 years later, looking for any associations between omega-3 blood

levels and a diagnosis of AF. They grouped the men into four categories

(quartiles), based on their blood levels of omega-3s. After comparing

the participants blood data with their medical records, the Finns found

that the men with the highest omega-3 levels when the study began were

35 percent less likely to have been diagnosed with AF by the end of the

study some 18 years later. And the results held a real surprise. DHA

outdoes EPA: Finding further bolsters DHA as key heart allyPeople have

been led to believe that of the two key omega-3s in fish oil EPA and DHA

the most important one for cardiac health is EPA, based on its

anti-inflammatory effects. This assertion is scientifically unfounded in

fact, DHA appears as or more important than EPA but has been exploited

by makers of fish oil products that have been chemically manipulated to

contain ratios of EPA to DHA far higher than those found in fish fat.

Further undermining the common EPA is better claim, the Finns analysis

found no association between EPA blood levels and risk of AF. Instead,

only high blood levels of omega-3 DHA were associated with the very

substantially reduced risk of AF. The positive association between DHA

levels and reduced risk of AF were strengthened further when the

researchers excluded the 233 men whod experienced a heart attack or

congestive heart failure. Interestingly, they found no associations

between AF risk and levels of mercury or short-chain, plant-food-derived

omega-3s. This study is surely not the last word in omega-3s and cardiac

arrhythmias. But it reinforces the recommendation to eat two servings of

fish per week, made by the American Heart Association and other expert

bodies. Sources

- Anand RG, Alkadri M, Lavie CJ, Milani RV. The role of fish oil in

arrhythmia prevention. J Cardiopulm Rehabil Prev. 2008

Mar-Apr;28(2):92-8. Review.

- Cheng JW, Santoni F. 3.Omega-3 fatty acid: a role in the management of

cardiac arrhythmias? J Altern Complement Med. 2008 Oct;14(8):965-74.

Review.

- Lombardi F, Terranova P. Anti-arrhythmic properties of N-3

poly-unsaturated fatty acids (n-3 PUFA). Curr Med Chem.

2007;14(19):2070-80.

- Reiffel JA, McDonald A. Antiarrhythmic effects of omega-3 fatty acids.

Am J Cardiol. 2006 Aug 21;98(4A):50i-60i. Epub 2006 May 26. Review.

- Virtanen JK, Mursu J, Voutilainen S, Tuomainen TP. Serum long-chain

n-3 polyunsaturated fatty acids and risk of hospital diagnosis of atrial

fibrillation in men. Circulation. 2009 Dec 8;120(23):2315-21. Epub 2009

Nov 23.