According to a new study from Australia increased intakes of omega-3 fatty acids may be linked to a younger biological age in older people with mild cognitive impairment.
In the randomized controlled trial, 33 participants over the age of 65 with mild cognitive impairment received either omega-3 fatty acid supplements containing mainly eicosapentaenoic acid (1.67 g EPA + 0.16 g DHA/day), docosahexaenoic acid (1.55 g DHA + 0.40 g EPA/day) or the omega-6 fatty acid linoleic acid (LA, 2.2 g/day) for six months (1). The length of the telomeric ends of chromosomes in samples of the partici- pants’ red blood cells was measured and compared. The study results showed that increased levels of DHA in red blood cells was significantly associated with reduced telomere shortening in the group with increased DHA intakes. The group receiving LA exhibited the greatest shortening of telomere length, compared with the DHA and EPA groups.
The researchers commented that these findings confirm earlier study results indicating potential relationships between high blood levels of marine omega-3 fatty acids and a low rate of telomere shortening, a potential increase of average telomere length and elevated omega-3 fatty acid intakes, and high blood levels of omega-3 fatty acids and a reduced cellular aging in people with coronary heart disease (2, 3).
The ends of chromosomes, called telomeres, are made up of a DNA sequence that protects the chromo- somes from fusing with each other or rearranging during cell division. The aging of normal, healthy cells is linked to a telomerase shortening mechanism, which limits cells to a fixed number of divisions. With each replication the telomeres shorten, and when they are totally consumed, the cells are destroyed (apoptosis). Previous studies have reported that telomeres are highly susceptible to damage by oxidative stress. Damage of the telomeres is thought to be one of the most critical events that initiate genome instability leading to accelerated aging, cognitive decline and neurodegenerative disease (e.g., Alzheimer’s disease).