Telomeres - the protective tips of the cells’ chromosomal ‘shoelaces’ – tend to shorten with age. A new trial at Ohio State found that supplemental omega-3 fatty acids supported both reduced inflammation and telomere ‘lengthening’ in subjects' immune cells. A strong suggestion that “inflammation is what’s driving the changes in the telomeres.”
Taking enough omega-3 fatty acid supplements to change the balance of oils in the diet could slow a key biological process linked to aging, new research from Ohio State suggests.
The study - published Sep 23 by Brain, Behavior, and Immunity(1) - showed that most overweight and sedentary but healthy middle-aged and older adults who took omega-3 supplements for four months altered a ratio of their fatty acid consumption in a way that helped preserve tiny segments of DNA in their white blood cells. (Increasing the omega-3 part of the omega-6 to omega-3 ratio.)
These DNA segments, called telomeres, are known to shorten over time in many types of cells as a consequence of aging. They’re a ‘hot topic’ in science, and their tendency to shorten is associated with many age related problems such as heart disease.
According to lead author Jan Kiecolt-Glaser, PhD, a psycho-neuro-immunologist at Ohio State:
• Lengthening of telomeres in immune system cells was more prevalent in people who substantially improved the ratio of omega-3s to other fatty acids in their diet.
• Omega-3 supplementation also reduced oxidative stress, caused by excessive free radicals in the blood, by about 15% compared to effects seen in the placebo group.
Thus, says Dr. Kiecolt-Glaser:
“The telomere finding is provocative in that it suggests the possibility that a nutritional supplement might actually make a difference in aging.”
Inflammation… Oxidative Stress… Telomere Aging… Disease
In another recent publication from this study ("Omega-3 supplementation lowers inflammation in healthy middle-aged & older adults"), Dr. Kiecolt-Glaser and colleagues reported that omega-3 fatty acid supplements lowered inflammation in this same group of adults. “Inflammation in particular is at the heart of so many health problems. Anything that reduces inflammation has a lot of potentially good spinoffs among older adults,” they say.
Study participants took either 2.5 grams or 1.25 grams of active omega-3 polyunsaturated fatty acids, which are considered “good fats” that, when consumed in proper quantities, are associated with a variety of health benefits. Participants on the placebo group took pills containing a mix of oils representing a typical American’s daily intake.
The researchers say this combination of effects suggests that omega-3 supplements could represent a rare single nutritional intervention that has potential to lower the risk for a host of diseases associated with aging, such as:
• Coronary heart disease,
• Type 2 diabetes,
• And Alzheimer’s disease.
The omega-3 supplements were calibrated to contain a ratio of the two cold-water fish oil fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), of seven to one.
Previous research has suggested that EPA has more anti-inflammatory properties than DHA. However, says Ohio State nutritionist Martha Belury, a co-author of the study:
• Omega-3 supplementation alone doesn’t tell the whole story of how this dietary change can affect health.
• Also important is the ratio of omega-6 fatty acids to omega-3 fatty acids that are present in a person’s blood.
Omega-6 fatty acids come from vegetable oils, and since the 1960s, research has suggested that these oils, too, can help protect the cardiovascular system. However, the typical American diet tends to be heavy on omega-6 fatty acids and comparatively low in omega-3s that are naturally found in cold-water fish such as salmon and tuna.
While the ratio of omega-6 to omega-3 fatty acids in American diets averages about 15-to-1, researchers tend to agree that for maximum benefit, this ratio should be lowered to 4-to-1, or even 2-to-1.
The long chains – or bigger molecules – that make up EPA and DHA fatty acids are believed to be the secret to their effectiveness, Dr. Belury says.
Both groups of participants who took omega-3 supplements showed, on average, lengthening of telomeres compared to overall telomere effects in the placebo group. The relationship could have been attributed to chance, but when the researchers analyzed the participants’ omega-6 to omega-3 ratio in relationship to telomere lengthening, a lower ratio was clearly associated with lengthened telomeres.
“The idea we were looking at with the ratio of omega-6 to omega-3 fatty acids was an increase in the denominator to make the ratio smaller. In the United States, we need to focus on the omega-3 part because we don’t get enough of those,” Dr. Belury notes.
Measuring Oxidative Stress
The researchers also measured levels of compounds called F2-isoprostanes to determine levels of oxidative stress, which is linked to a number of conditions that include heart disease and neurodegenerative disorders.
Both omega-3 groups together showed an average overall 15% reduction in oxidative stress compared to effects seen in the placebo group.
When the scientists revisited their earlier inflammation findings, they also found that decreases in an inflammatory marker in the blood called interleukin-6 (IL-6) were associated with telomere lengthening. In their earlier paper on omega-3s and inflammation, they reported that:
• Omega-3 supplements lowered IL-6 by 10% to 12%, depending on the dose.
• By comparison, those taking a placebo saw an overall 36% increase in IL-6 by the end of the study.
“This finding strongly suggests that inflammation is what’s driving the changes in the telomeres,” Dr. Kiecolt-Glaser says.
She notes that the study group, though overweight (bmi 22.5 to 40) and sedentary, was disease-free and reported very little stress. None was taking medications to control mood, cholesterol or blood pressure. Therefore, “People who are less healthy than this group, and especially those who experience chronic stress, may gain even more benefits from omega-3 supplementation,” she says.
Among several co-authors located at the University of California, San Francisco, two are co-founders of Telome Health Inc., a telomere measurement company.
This work was supported in part by grants from the National Institutes of Health.
Source: Based on Ohio State University news release, Oct 1, 2012
1. Reference: “Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial,” Kiecolt-Glaser JK, et al. Ohio State University College of Medicine and College of Public Health; University of California San Francisco, USA.