Kiecolt-Glaser · Brain, behavior, and immunity 2013 · randomized controlled trial · n=106

Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial.

Cited 261 times in the scientific literature.

Level 2 - randomized trial

Individual randomized controlled trial

PubMed 23010452 · doi:10.1016/j.bbi.2012.09.004 · record verified 2026-08-30

What was done

In a double-blind randomized controlled trial lasting four months, 106 healthy, sedentary, overweight middle-aged and older adults were assigned to one of three groups: (1) 2.5 g/day omega-3 (n-3) polyunsaturated fatty acids (PUFAs), (2) 1.25 g/day n-3 PUFAs, or (3) placebo capsules reflecting typical dietary fatty acid proportions. Researchers measured leukocyte telomere length, telomerase activity, oxidative stress via serum F2-isoprostanes, and continuous changes in plasma n-6:n-3 PUFA ratios.

What was found

Omega-3 supplementation significantly reduced oxidative stress (p=0.02), with estimated geometric mean log-F2-isoprostanes 15% lower in the combined supplement groups compared to placebo. Direct between-group comparisons for telomerase and leukocyte telomere length showed no statistically significant differences. However, continuous analysis showed that leukocyte telomere length increased significantly as plasma n-6:n-3 PUFA ratios decreased (p=0.02).

Why it matters

The trial provides randomized evidence that omega-3 supplementation lowers oxidative stress in overweight older adults, and suggests that shifting the systemic fatty acid balance toward higher omega-3s may slow cellular aging markers.

Limits

The sample size was modest (n=106) and the intervention period of four months is relatively short for evaluating telomere dynamics. Group-level differences in telomere length and telomerase were non-significant; the telomere finding relied on continuous plasma n-6:n-3 ratio shifts rather than randomized group assignment alone. The study only included sedentary, overweight middle-aged and older adults, limiting generalizability to other populations.

Cited by