Omega-3 fatty acids, those found in coldwater fish, are good for us for lots of reasons. We already know that. New research has discovered that another benefit of these fats may be the slowing down of a biological process that occurs with aging.

Over 100 overweight or obese, but otherwise healthy, middle-aged adults took either 2.5 grams or 1.25 grams of omega-3 supplements while others were given a placebo. The participants’ intake of omega-6 fatty acids was studied as well because Americans tend to have diets low in omega-3s but rich in omega-6 fatty acids.

Telomeres lengthened in immune system cells among the people who took the omega-3 supplements and consequently improved the ratio of omega-3s to other fatty acids in their diet.

Among those who took either dose of the omega-3 supplements, tiny segments of DNA were preserved in the white blood cells. These segments, called telomeres, shorten with age in certain types of cells.

Telomeres became longer in immune system cells of people who took the omega-3 supplements and consequently improved the ratio of omega-3s to other fatty acids in their diet. In analyzing the results of the study, the researchers, from the Ohio State University, found that lower ratios of omega-6 to omega-3 fatty acids were associated with the lengthening of the telomeres.

Telomeres play an important role in the aging process. They are bits of DNA found at the end of chromosomes. Often likened to the plastic ends of shoelace strings, telomeres keep DNA from unraveling and help cells divide. However, the more cells divide, the shorter the telomere gets, until the cell can no longer divide. The result is chromosome ends that fray and stick to each other. Genetic information becomes scrambled, and cells malfunction, causing cancer, other diseases, or death.

The typical American diet tends to include substantially more omega-6s, found in vegetable oils, than omega-3s. The researchers believe this ratio, which is currently about 15 to 1 should be lowered to 4 to 1 or even 2 to 1. Eating more fish containing omega-3s or taking supplements is the only way to achieve this.

The connection between telomere lengthening and omega-3 supplements is exciting, according to the researchers, because it suggests that a nutritional supplement could make a difference in aging.

The study was published online in Brain, Behavior, and Immunity and is scheduled for later print publication.