Abstract
BACKGROUND: Although circulating fatty acids (FAs) are associated with the development of major chronic diseases (MCDs), their relationships with healthy longevity remain unclear.
OBJECTIVES: The study aims to examine the relationships between specific plasma FAs and the odds of healthy aging.
METHODS: This prospective cohort study included 15,333 participants aged 64 y or older who were free of MCDs at baseline. Exposures were relative levels of different FAs (% total FAs) in the plasma. The primary outcome was healthy aging, defined as survival to age 80 without developing MCDs during the follow-up. Multivariable logistic regression models were used to calculate odds ratio (OR) and 95% confidence interval (CI) of healthy aging associated with specific FAs. Causal mediation analyses were conducted on biomarkers related to age acceleration or several other biological pathways.
RESULTS: A total of 9291 participants achieved healthy aging. Saturated or monounsaturated FAs were not associated with healthy aging. Relatively higher levels of polyunsaturated FAs (PUFAs) were associated with higher odds of healthy aging (OR comparing the extreme quartiles: 1.32; 95% CI: 1.04, 1.68; P-trend < 0.001), with similar associations for n-3 PUFAs and n-6 PUFAs. Docosahexaenoic acid (DHA), non-DHA n-3 PUFAs, and linoleic acid (LA), but not non-LA n-6 PUFAs, were positively associated with the odds of healthy aging. A higher ratio of n-6/n-3 PUFAs was associated with lower odds of healthy aging (OR: 0.88; 95% CI: 0.79, 0.97). Six biomarkers were identified as significant mediators for the above associations, with age acceleration explaining 16.1% and 37.4% of the relationships of n-3 PUFAs and n-6/n-3 PUFAs ratio with healthy aging, respectively.
CONCLUSIONS: Relatively higher levels of plasma PUFAs, including n-3 PUFAs (both DHA and the non-DHA components) and n-6 PUFAs (LA but not the non-LA components), are associated with higher odds of healthy aging, potentially through retarding the biological aging processes.