There’s a difference between living a long life and living a long healthy life — not just surviving, but thriving in old age without any major illness or disability.
New research suggests eating more seafood could play a role in making that happen. Among older people, having a higher blood level of omega-3 fatty acids found in fish was associated with a lower risk of unhealthy aging, a study published Wednesday in The BMJ found.
“We should think about how to increase that level in our body,” lead author Heidi TM Lai, a postdoctoral fellow at the Friedman School of Nutrition Science and Policy at Tufts University, told TODAY.
“We’re living longer burdened with disease so as researchers, we want to start to focus on the quality of life and not just longevity.”
Omega-3s are a type of healthy fat humans must get from food. The study findings suggest it’s a good idea for older adults to get more omega-3s in their diet, specifically through seafood, the authors wrote. The best sources include cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines.
The researchers analyzed the omega-3 blood levels of 2,622 adults using data from the Cardiovascular Health Study of older Americans. Members of the group were 74 years old on average when the data was first collected in 1992 and 1993. The blood tests were repeated six and 13 years later.
The tests measured the participants’ levels of four types of omega-3s: three that people get from seafood, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA); and one that’s found in plants, alpha linolenic acid (ALA). The seafood-derived fatty acids are known as long chain omega-3s.
Over the years, 89 percent of the study participants experienced unhealthy aging, developing chronic diseases or showing physical or mental declines. But 11 percent enjoyed healthy longevity — they had no heart disease, cancer, physical limitations, cognitive issues or any problems with daily living.
When researchers crunched the data, it turned out that having higher blood levels of the long chain omega-3s found in seafood — but not the kind derived from plants — was associated with an 18 percent lower risk of unhealthy aging, the study found.
The people who had the highest levels of omega-3s ate one more serving of fish per week than the lowest-level group.
“The takeaway is that this study supports national dietary guidelines to consume more seafood,” Lai said. “If you’re aged 65 and above, this would be a good idea.”
Some caveats to remember: First, omega-3 levels can be influenced by both diet and metabolism, so some genetic factors are at play; second, this was an observational study, so researchers can't say eating more seafood resulted in better health in aging, Lai noted. A companion editorial published in The BMJ cautioned against using the findings "to inform public health policy or nutritional guidelines."
The research was also not designed to analyze the efficacy of fish oil supplements, so Lai declined to comment on that issue. Fish oil is the most popular non-vitamin dietary supplement taken by U.S. adults, according to the National Health Interview Survey.
Omega-3 supplements don’t reduce the risk of heart disease and the evidence is inconclusive or doesn’t show they’re beneficial for other conditions, but people who eat seafood one to four times a week are less likely to die of heart problems, the National Center for Complementary and Integrative Health noted.
In the study, people with the highest omega-3 blood levels ate two servings of seafood a week, or one serving more per week than people with the lowest omega-3 blood levels.
Want to know your levels? Ask your doctor about it if it’s something you’re concerned about, Lai said.
Paul Greenberg, author of “The Omega Principle: Seafood and the Quest for a Long Life and a Healthier Planet,” had his blood tested after a year of eating fish at every meal for a year. He had around 11 percent omega-3 levels his blood — most Americans are below 5 percent. A finding above 8 percent is desirable.
“Somebody said to me that I had the blood of a Sicilian fisherman circa the 1890s,” Greenberg told TODAY.