Supplementing fish oils appears to offer some protection against cardiovascular disease, but whether this effect is caused by dulling the stress-responsive system is unclear.
In a large prospective study of nearly half a million people, higher fish intake was linked to decreased all-cause mortality. One factor linked to biological aging is the length of telomeres, which are strands of DNA at the ends of chromosomes, and there is good evidence that telomeres shortening is linked to increased mortality and as with people who consume higher amounts of omega-3 fatty acids, there is less risk of telomeres shortening. In addition, increased physiological stress is a risk factor for many physical and mental illnesses, and there is again evidence that omega-3 fatty acids weaken the pro-inflammatory response to psychological stress to some extent. Taken together, these results suggest that supplementing with omega-3 fatty acids can positively affect markers of stress reactivity. This was the hypothesis tested by a team from the Behavioral Medicine Research Institute at Ohio State University College of Medicine in Ohio, United States, who studied the response of a group of people to a social stress test. The team divided the participants into three groups, who received either 2.5 g / day, 1.25 g / day omega-3 or placebo for 4 months. At the beginning of the study, all participants had to undergo the stress test, in which a 5-minute speech was given without the use of aids or notes. Both saliva and blood samples were taken before the stress test and 0.75, 1.25, 1.75 and 2 hours after, and the test was repeated at the end of the study. Parameters assessed included cortisol, telomerase (an enzyme that maintains and restores telomeres), and several markers that promote inflammation, interleukins 6, 10, and 12, and tumor necrosis factor (TNF). Participants also had to rate their anxiety levels before and after the test.
A total of 138 people (63% female) with an average age of 51.1 years and 72% white descent were recruited. Among those who took omega-3 2.5 g / day, their salvia cortisol levels were 19% lower during the last stress test than those who were given placebo (p = 0.01), although this difference was for the 1.25 g / day group was not significant. Similarly, the high-dose supplement group had 33% lower interleukin-6 levels compared to placebo (p = 0.007). However, there were no differences from the other interleukin levels or TNF. While the telomerase levels remained unchanged in both supplement groups, the levels fell by 24% between 45 and 120 minutes after the stress test.
The authors commented on how 2.5 g / day omega-3 fatty acid supplementation blocked the stress-related decline in telomerase levels and, in a dose-dependent manner, lowered both cortisol and proinflammatory interleukin-6 levels. They suggested that omega-3 supplements have a unique stress-buffering effect on cellular aging biomarkers, and concluded that their data, while preliminary, could, if replicated, limit the effects of repeated stress.
Madison AA et al. Omega-3 supplementation and stress reactivity of biomarkers for cell aging: an additional sub-study of a randomized, controlled study in middle-aged adults. Mol Psychiatry 2021.