New research links red blood cell levels of omega-3s, the fatty acids plentiful in fish, to nearly five more years of life expectancy, according to a report in the American Journal of Clinical Nutrition (McBurney et al., 2021, O’Neill, 2021).
That is roughly what we see among the Japanese, who have higher omega-3 blood levels than Americans, and live on average almost five years longer, the authors note.
Smoking cigarettes, on the other hand, has about the same impact, but in the other direction, increasing your risk of dying younger.
The bigger picture: measures of fatty acids may add up to as strong a predictor of life expectancy as standard markers of heart health like blood pressure, they said (McBurney et al., 2021).
What the scientists did
The most powerful scientific conclusions about nutrition come from large, long-duration studies. Back in 1948, government scientists recruited residents of Framingham, Mass., and began asking them about their habits and health every two years. Over time, this research identified risk factors that increased the risk of dying from heart disease or stroke, most notably smoking, diabetes, and certain blood pressure and cholesterol levels.
In 1971, children of the original cohort members (and their spouses), 5,124 people in all, were assembled into a new group that has now been assessed seven times (Framingham study, 2021).
In 2018, researchers found that people in the second Framingham group who had the highest blood levels of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were a third less likely to die for any reason during the follow-up period, between the ages of 66 and 73, than people who had the lowest levels (Harris et al., 2018).
In the new research, scientists drew again upon data from the second Framingham group, this time a subset of seniors: 2,240 people over the age of 65, followed for 11 years (McBurney et al., 2021).
Both teams included scientists from the Fatty Acid Research Institute, a nonprofit founded by William Harris, a co-author of more than 300 scientific papers on fatty acids and health, who has received five National Institute of Health grants to study omega-3s. Scientists in the later research were also associated with institutions in Barcelona, Spain; Guelph, Canada, and Boston and Sioux City.
You might say that as a group, they really know about the benefits of fatty acids! Yet the conclusion surprised even them.
For this study, the team looked at 27 fatty acids found in samples of red blood cells and ran statistical tests comparing how they related to survival. It turned out that EPA and DHA combined with three other fatty acids predicted life expectancy as reliably as the well-known Framingham risk factors. The combined measure was like a “fatty acid fingerprint,” they wrote.
“The finding that any [fatty acid]-based metric would have predictive power similar to that of these well-established standard risk factors was unexpected, and it suggests that [this combination of fatty acids]—via unknown mechanisms—somehow reflects [a real-life] milieu that consolidates into 1 measure the impact on the body of all these standard risk factors,” they wrote.
The apparently helpful saturated fats were myristic acid, which we can get from dairy and coconut, palmitoleic acid, most plentiful in macadamia nut oil, and behenic acid, found in canola and peanut oil.
“This reaffirms what we have been seeing lately,” said Aleix Sala-Vila, a postdoctoral researcher in the Hospital del Mar Medical Research Institute, in Barcelona, Spain, “not all saturated fatty acids are necessarily bad” (0’Neill, 2021). It’s possible, for example, that myristic acid helps prevent Type 2 diabetes or heart disease.
The value of omega-3s is well-known. For two decades, the American Heart Association has recommended that people who already have a cardiovascular disease consume omega-3s from fish or fish oil to cut their risk of heart attack or stroke (Kelley-Hedgepeth, 2021).
It’s important to remember that diet isn’t the whole story. Even for fatty acids we get from food, your genes play a role, affecting how well you metabolize them. In this second Framingham group, diet seems to explain 40 percent of the variation scientists find in omega-3 levels in red blood cells, the authors note.
Seriously, my blood says how long I’ll live?
Now, you may be wondering if a researcher could draw your blood and then announce how long you’ll live. For better or worse, the answer is “No.” Individuals vary a lot from these group findings. Heavy smokers have lived well past a hundred (and no that’s not a good reason to smoke!) (Dovey, 2018).
However, in future, blood tests may help us identify risks earlier and fine-tune our diets to nudge things in the right direction. “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,” Sala-Vila said (0’Neill, 2021).
In other words, eat seafood.