Cells contain a string of DNA with genetic information. At each end of the string are telomeres; protective caps that keep DNA in order as the cell replicates. Each time cells replicate, telomeres shorten, until there is no telomere left and the cell dies. There is a direct link between telomere length and aging.

In this telomere study, 33 older adults with mild cognitive impairment took the omega-3s EPA and DHA, or the omega-6 linoleic acid. Doctors gave a high dose of EPA with a low dose of DHA, or the reverse. The daily doses were 1,670 mg EPA plus 160 mg DHA, 1,550 mg DHA plus 400 mg EPA, or 2,200 mg linoleic acid. Previous studies suggest we should maximize omega-3s in our diet and minimize omega-6s like linoleic acid.

After six months, doctors saw an overall trend toward shorter telomeres, but the omega-6 group had the most shortening. Also, in the high-DHA group, as DHA levels increased, telomere shortening decreased. Doctors said these findings build on recent reports that omega-3s appear to slow the telomere shortening that occurs with age.

Reference: Nutrition; 2014 Apr;30(4):489-491.