Higher PUFA levels may delay ageing process

Increased levels of plasma polyunsaturated fatty acids (PUFAs), including n-3 PUFAs (docosahexaenoic [DHA] and the non-DHA components) and n-6 PUFAs (linoleic acid [LA] but not the non-LA components), appear to promote healthy ageing, potentially slowing down the biological ageing process, suggests a recent study.

A total of 15,333 participants aged ≥64 years who were free of major chronic diseases (MCDs) at baseline were included in this prospective cohort study. Relative levels of different FAs (% total FAs) in the plasma served as exposures. Healthy ageing, the primary outcome, was defined as survival to age 80 without developing MCDs during follow-up.

The investigators calculated the odds ratio (OR) and 95 percent confidence interval (CI) of healthy ageing associated with specific FAs using multivariable logistic regression models. They also performed causal mediation analyses on biomarkers associated with age acceleration or other biological pathways.

Of the participants, 9,291 achieved healthy ageing, which showed no association with saturated or monounsaturated FAs. In contrast, the likelihood of attaining healthy ageing was greater among individuals with relatively higher levels of PUFAs (OR, 1.32, 95 percent CI, 1.04‒1.68; p_trend<0.001), including n-3 and n-6 PUFAs.

Similarly, DHA, non-DHA n-3 PUFAs, and LA (but not non-LA n-6 PUFAs) showed a positive association with healthy ageing.

On the other hand, a higher ratio of n-6/n-3 PUFAs correlated with a lower likelihood of achieving healthy ageing (OR, 0.88, 95 percent CI, 0.79‒0.97). Several biomarkers significantly mediated these associations, with age acceleration being accountable for 16.1 percent and 37.4 percent of the relationships of n-3 PUFAs and n-6/n-3 PUFAs ratio with healthy ageing, respectively.