Consumption of omega-3 is widely known for a lower risk of diseases like cardiovascular disease, cancer, even memory loss. Now scientists know blood level of omega-3 could be a good predictor of mortality.
Since the discovery of omega-3 in 1929, scientists have conducted extensive research linking omega-3 supplementation and a lower risk of cardiovascular disease, some specific forms of cancer, depression, and cognitive decline to increased life span (Champigny et al., 2018).
Though the association between omega-3 consumption and a lower risk of all-cause mortality in humans appears inconclusive in some research (Rizos et al., 2017), a recent study reveals blood levels of omega-3 fatty acids can be good a predictor of mortality. A 1% increase in omega-3s in the blood is associated with a change in mortality risk similar to quitting smoking. Also, maintaining a higher level of omega-3s in the blood increases life expectancy by almost five years. The study results are recently published in the American Journal of Clinical Nutrition (McBurney et al., 2021).
Omega-3 was first discovered by George Burr and Mildred Burr in 1929 (Burr et al., 1973). Since then, this compound has attracted a range of scientific topics about its chemistry, natural sources, health effects, and mechanism of action.
On August 9, 2021, searching the PubMed database with the keyword ‘omega-3’ reveals over 33,000 research articles, two-third of which were published in the last decade, primarily focusing on the health benefits of omega-3 or omega-3 rich food consumption in reducing the risk of cardiovascular disease, cancer, depression, and cognitive decline.
Chemically the omega−3 fatty acids are polyunsaturated fatty acids (PUFAs) characteristic of a double bond between 3rd and 4th carbon atoms from the terminal methyl group.
The three main physiologically important omega-3 are α-linolenic acid (ALA), and eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Among omega-3s, ALA, usually found in plant oils, is essential to the human body and can only be obtained through diet or supplementation. However, the other two, EPA and DHA, commonly found in fish oils, our body can make using ALA by creating additional double bonds along its carbon chain and extending it.
When we age, the body’s ability to make the longer-chain omega−3 fatty acids from ALA lowers. If the demand is not replenished via supplementation, the body may fall at risk of disease, increasing mortality.
Recently, researchers at Hospital del Mar Medical Research Institute (IMIM), and The Fatty Acid Research Institute in the United States, in collaboration with several universities in the United States and Canada, showed that omega-3 fatty acids levels in the blood are as good a predictor of mortality from any cause as smoking. In the study, the scientists collected data from Framingham Offspring Cohort, a long-term study group monitoring residents of a town in Massachusetts, in the United States, since 1971.
Monitoring 2,200 people over eleven years
The study monitored all 2240 people over the age of 65 for an average of 11 years. The researchers analyzed blood fatty acid levels to compare RBC fatty acid levels with common cardiovascular disease (CVD) risk factors to predict mortality.
They systematically evaluated the association of 8 common risk factors (age, sex, total cholesterol, HDL cholesterol, hypertension treatment, blood pressure, smoking, and diabetes) and 28 FA metrics with all-cause mortality.
The study found that omega-3, along with three other fatty acids, fulfill their target. Interestingly, two of those four fatty acids they found were traditionally associated with increased CVD risk.
“This reaffirms what we have seen lately; not all saturated fatty acids are necessarily bad,” says Dr Sala-Vila. Indeed, not all fatty acid levels in the blood can be modified by diet, as with omega-3 fatty acids.
These results may show that a personalized dietary recommendation is necessary based on the blood levels of different fatty acids.
Dr Sala-Vila further added, “What we have found is not insignificant. It reinforces the idea that small changes in diet in the right direction can have a much more powerful effect than we think, and it is never too late or too early to make these changes.”
Replication of the results is needed in other study populations to validate this FA fingerprint as a predictor of all-cause mortality.
The researchers are now planning to analyze the same bio-markers in similar population groups but of European origin to determine if the results obtained in the current study can also be extrapolated outside of the United States.
The American Heart Association recommends consuming oily fish such as salmon, anchovies, or sardines twice a week because of the beneficial effects of omega-3 fatty acids.
Burr, G. O. and M. M. Burr (1973). “Nutrition classics from The Journal of Biological Chemistry 82:345-67, 1929. A new deficiency disease produced by the rigid exclusion of fat from the diet.” Nutr Rev 31(8): 248-249. 10.1111/j.1753-4887.1973.tb06008.x.
Champigny, C. M., R. P. J. Cormier, et al. (2018). “Omega-3 Monoacylglyceride Effects on Longevity, Mitochondrial Metabolism and Oxidative Stress: Insights from Drosophila melanogaster.” Mar Drugs 16(11). 10.3390/md16110453.
McBurney, M. I., N. L. Tintle, et al. (2021). “Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort.” The American Journal of Clinical Nutrition. 10.1093/ajcn/nqab195.
Rizos, E. C. and M. S. Elisaf (2017). “Does Supplementation with Omega-3 PUFAs Add to the Prevention of Cardiovascular Disease?” Curr Cardiol Rep 19(6): 47. 10.1007/s11886-017-0856-8.