Analysis of data from the Framingham Offspring Cohort collected over 11 years indicated that the omega-3 index was a strong predictor of all-cause mortality in the 2,240 participants who did not have without prevalent cardiovascular disease at the start of the study.
“It is interesting to note that in Japan, where the mean Omega-3 Index is greater than 8%, the expected life span is around five years longer than it is in the United States, where the mean Omega-3 Index is about 5%. Hence, in practice, dietary choices that change the Omega-3 Index may prolong life,” said Michael McBurney, PhD, FCNS-SCN, lead researcher in this study.
“In the final combined model, smoking and the Omega-3 Index seem to be the most easily modified risk factors. Being a current smoker (at age 65) is predicted to subtract more than four years of life (compared with not smoking), a life shortening equivalent to having a low vs. a high Omega-3 Index.”
The Omega-3 Index measures the level of long-chain omega-3 fatty acids, EPA+DHA, in red blood cell membranes expressed as a percent of total fatty acids.
An Omega-3 Index in the range of 8-12% is one indicator of better overall health. As a part of an overall healthy lifestyle, an Omega-3 Index of 8% or higher may help to maintain heart, brain, eye and joint health. An intermediate Omega-3 Index is between 4% and 8%, and a low Omega-3 Index is 4% and below. Most Americans have an Omega-3 Index below 4%.
Dr McBurney and his collaborators at the Fatty Acid Research Institute (FARI) systematically evaluated the association of eight standard risk factors (age, sex, total cholesterol, HDL cholesterol, hypertension treatment, systolic blood pressure, smoking status, and prevalent diabetes) and various fatty acid metrics with all-cause mortality.
The Omega-3 Index was identified among the fatty acid metrics identified as significant predictors of all-cause mortality in at least five of the different models.
According to researchers in this study, the finding that any FA-based metric would have predictive power similar to that of the well-established standard risk factors was unexpected, and it suggests that red blood cell fatty acids —via imperfectly understood mechanisms—somehow reflects an in vivo milieu that consolidates into one measure the impact on the body of all these standard risk factors.
“The information carried in the concentrations of four red blood cell fatty acids was as useful as that carried in lipid levels, blood pressure, smoking, and diabetic status with regard to predicting total mortality,” said Dr. Bill Harris, co-author on this study and co-inventor of the Omega-3 Index.
“This speaks to the power of the Omega-3 Index as a risk factor and should be considered just as important as the other established risk factors, and maybe even more so.”
The researchers said the results need to replicated in other cohorts before the FA fingerprint as a predictor of all-cause mortality is validated.
The study was supported in part by the Institute for the Advancement of Food and Nutrition Sciences (IAFNS) through an International Life Sciences Institute North America Lipid Committee grant.
Commenting independently on the study’s findings, Harry Rice, PhD, VP of regulatory & scientific affairs for the Global Organization for EPA and DHA Omega-3s (GOED), told us: "Since FARI was founded, it has been doing great work - this recent study is no exception.
"Now that it has been demonstrated that the inclusion of three other fatty acids added to the predictive power of the omega-3 index, it will be interesting to see if this holds true when studying other populations. If it does, in the future, will consideration be given to reporting the sum of five fatty acids, instead of two?"
Source: The American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1093/ajcn/nqab195
“Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort”
Authors: M.I. McBurney, et al.