Association of omega-3 and omega-6 fatty acid intake with leukocyte telomere length in US males

Background: Omega-3 (n–3) and omega-6 (n–6) fatty acids may contribute to oxidative stress and inflammation, which are related to telomere shortening. Evidence supporting an association between intake of n–3 or n–6 fatty acids and leukocyte telomere length (LTL) in males has been limited. Objectives: We conducted a cross-sectional study to examine the associations of total or individual n–3 or total n–6 fatty acid intake with LTL in US males. Methods: We included 2,494 US males with LTL measurement from 4 nested case–control studies within the Health Professionals Follow-Up Study. Individuals with previous histories of cancers, diabetes, and cardiovascular diseases at or before blood collection were excluded. Blood collection was performed between 1993 and 1995, and relevant information including n–3 and n–6 intake was collected in 1994 by questionnaire. The LTL was log-transformed and Z scores of the LTL were calculated for statistical analyses by standardizing the LTL in comparison with the mean within each selected nested case–control study. Results: We found that consumption of DHA (22:6n–3) was positively associated with LTL. In the multivariable-adjusted model, compared with individuals who had the lowest intake of DHA (i.e., first quartile group), the percentage differences (95% CIs) of LTL were −3.7 (−13.7, 7.5), 7.0 (−4.3, 19.7), and 8.2 (−3.5, 21.3) for individuals in the second, third, and fourth quartiles of consumption, respectively (P-trend = 0.0498). We did not find significant associations between total n–3 or total n–6 fatty acid intakes and LTL. In addition, we found that males who consumed canned tuna had longer LTL than those who did not; in the multivariable-adjusted model, the percentage difference of LTL was 10.5 (95% CI: 1.3, 20.4) (P = 0.02). Conclusions: Our results suggest that higher intakes of DHA and canned tuna consumption are associated with longer LTL.