Listen to your Heart Beat: Omega-3 Fatty Acids and Muscle Function
A human hearts beat 100,000 times per day, 35 million times per year, and more than 2.5 billion times during the average lifetime. It pushes about 5.6 liters (6 quarts) of blood around the body three times every minute. An amazing amount of work. Most people understand that omega-3 long-chain polyunsaturated fatty acids (LCPFUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have heart health benefits. The mechanism of action is presumed to be related to LCPUFA effects on blood lipid concentrations. There may be more to the EPA and DHA story than changes in lipid fractions.
The heart is a muscle. Reinders and colleagues studied the relationship between plasma phospholipid LCPUFA and measures of muscle size (leg and hand) and strength. Data were collected from volunteers (66-96y) participating the in the Age, Gene/Environment Susceptibility – Reykjavik Study. Most participants had quite high EPA and DHA concentrations which may explain the inconsistent observations when comparing high vs low tertiles. Why? Nutrient – function relationships exist when nutrient intakes are suboptimal to deficient. Nevertheless, positive associations were observed between total omega-3 LCPUFA and thigh muscle strength, knee extension strength, and handgrip strength.
In the US, the FDA approved an omega-3 fatty acids and coronary heart disease (CHD) health claim as part of a diet low in saturated fat and cholesterol. The claim reflects scientific evidence that lowering blood cholesterol may reduce CHD risk and reducing consumption of saturated fats by replacement will help achieve this goal.
So omega-3 fatty acids, EPA and DHA, may benefit the heart muscle, not just the calcification and plaque accumulation within its blood vessels. More research is needed to confirm this association of plasma phospholipid omega-3 LCPUFAs with muscle size and strength.
In the meantime, take this quiz to see if you know the best fish sources of EPA and DHA. And Happy Hallowe’en!
Reinders I, Song X, Visser M, Eiriksdottir G, Gudnason V, Sigurdsson S, Aspelund T, Siggeirsdottier K, Brouwer IA, Harris TB, Murphy RA. Plasma phospholipid PUFAs are associated with greater muscle and knee extension strength but not with changes in muscle parameters in older adults. 2014 J Nutr doi: 10.3945/jn.114.200337
Omega-3 Fatty Acids & Coronary Heart Disease. FDA, Docket No. 2003Q-0401. Summary of Qualified Health Claims Subject to Enforcement Discretion. Accessed Oct 31, 2014
Scientific Opinion on the substantiation of a health claim related to “low fat and low trans spreadable fat rich in unsaturated and omega-3 fatty acids”and reduction of LDL-cholesterol concentrations pursuant to Article 14 of Regulation (EC) No 1924/2006. 2011 EFSA J doi: 10.2903/j.efsa.2011.2168