We already knew omega-3s -- those essential fatty acids necessary to maintain normal body function found in salmon and tuna-- were good for you. But a new study has found another benefit to taking omega-3 supplements: slowing down a biological process associated with aging.
Small segments of DNA located in white blood cells were preserved in those who altered their fatty acid intake by using omega-3 supplements, researchers found. Those DNA pieces are known as telomeres, which can shorten over time thanks to aging and disease. Telomere lengthening was seen in the immune system cells of study participants who "substantially improved the ratio of omega-3s to other fatty acids in their diet," according to a press release for the study.
More than 100 overweight or obese adults (average age 51) who live fairly sedentary lifestyles participated in the study. Some were given a placebo, while others took either 2.5 grams or 1.25 grams of active omega-3 polyunsaturated fatty acids. Researchers also considered the participant's intake of omega-6 fatty acids -- the type of polyunsaturated fat typically found in vegetable oils. (Americans tend to have diets rich in omega-6s but low in omega-3s.)
Of those who took one of the two dosages of omega-3 supplements, a definite lengthening in the telomeres was apparent when compared to the telomeres in the placebo group, the release stated. But when researchers took the ratio between omega-6s and omega-3s into consideration, "a lower ratio was clearly associated with lengthened telomeres."
"While the ratio of omega-6 to omega-3 fatty acids [in the typical American diet] 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 release said. (This finding may add to the back and forth on whether or not the ratio of omega-6s to omega-3s actually matter.)
Researchers said they find the connection between omega-3 supplements and telomere length exciting because "it suggests the possibility that a nutritional supplement might actually make a difference in aging," said Jan Kiecolt-Glaser, the study's lead author and professor of psychiatry and psychology at Ohio State University.
Telomeres play a vital role in the human aging process. These bits of DNA are found at the end of our chromosomes and are often likened to the ends of shoelace strings -- they keep the double helix strands of our DNA from unraveling and help our cells divide. Yet the more they divide, the shorter they get, and when telomeres get too short it can lead to cell inactivity or death. In fact people 60 and older with shorter telomeres are "three times more likely to die from heart disease and eight times more likely to die from infectious disease," according to the University of Utah's Genetics Science Learning Centers.
A past study using mice "engineered to age faster" found that lengthening the rodent's telomeres reversed the aging process, ABC News reported. After gene therapy, researchers noticed that the mice's fur went from grey back to its original dark brown and its brain size -- which had decreased by 75 percent much like the brain's of Alzheimer's patients -- returned to normal.