The headlines for a recently published study on aging might have you running for the omega-3 supplement aisle:
Omega-3s in Fish Oils Tied to Healthy Aging screams the New York Times, among others
So what’s the rest of the story? First, this is one of the better studies I’ve seen, because the results are based on actual blood levels of omega-3 fatty acids, not just on people’s frequently hazy or inaccurate recalls of what they’ve been eating for the past few years. You can’t argue with blood levels. Additionally, the researchers were particularly focused on omega-3 fats from fish, so fish intake was assessed.
Over 2600 older adults (average age 74) were followed for 14 years. Medical history, diet (particularly fish intake), lifestyle and blood measurements were assessed periodically throughout the study.
The researchers compared the omega-3 blood levels to what they defined as “healthy aging” — the absence of:
- cardiovascular disease
- lung disease
- chronic kidney disease
- cognitive dysfunction
- physical dysfunction that adversely impacts daily life
The results indicated that higher blood levels of long chain omega-3 fats (EPA, DHA and DPA) were linked to greater likelihood of healthy aging. This was described as “an 18% lower risk for unhealthy aging”; in other words, not a huge amount. Only 11% of the people who completed the study experienced that definition of healthy aging.
Here’s one other pretty significant finding: blood levels of alpha linolenic acid (ALA), the 18-carbon omega-3 fat found in plant foods was not linked to healthy aging. Only the long chain omega-3s which we get primarily from fish were linked to benefits. This is rather important, because many people avoid fish, such as vegans and vegetarians. While they might consume ALA from plant foods like flax or walnuts, it might not be so beneficial.
The other issue for this study is the absence of omega-3 supplements. The study was focused only on omega-3 from fish. You have to eat significant amounts of fish to maintain higher blood levels of omega-3. If people don’t eat fish, supplements are certainly a reasonable alternative. I think it would be more helpful to establish some blood level that was linked to healthy aging, and suggest omega-3 intakes that would support those levels. Keeping in mind, that plant-based omega-3 supplements, such as flax, do not contain the long chain omega-3 fats that showed beneficial effects in this study.
So yes, omega-3 fat intake is linked to healthy aging. But the study didn’t show that omega-3 fats are uniquely responsible for healthy aging, nor that higher intakes prevent chronic diseases of aging. Just that people with the highest intakes from fish were less likely to experience unhealthy aging. Despite the limitations, I like this study. It gives us more solid reason to include omega-3 fatty acids in our diets. While you might see it as a reason to eat more high fat fish, I don’t see why omega-3 supplements wouldn’t be a reasonable alternative.