Lifestyle Factors Associated with Circulating Very Long-Chain Saturated Fatty Acids in Humans: A Systematic Review of Observational Studies

Year Published: 2022

Kira Zhi HuaLai1Nagam A.Yehia1†ZhilaSemnani-Azad12†Sonia BlancoMejia13Beatrice A.Boucher1VasantiMalik12Richard P.Bazinet1Anthony J.Hanley

A total of 12 studies consisting of mostly cross-sectional analyses were included in this review. The majority of the studies documented the associations of dietary intake with total plasma or red blood cell VLCSFAs, in which a range of macronutrients and food groups were examined. Two cross-sectional analyses showed a consistent positive association between total fat and peanut intake and 22:0 and 24:0 and an inverse association between alcohol intake and 20:0 and 22:0. Furthermore, a moderate positive association between physical activity and 22:0 and 24:0 were observed. Lastly, there were conflicting results on the effects of smoking on VLCSFA. Most of the studies had a low risk of bias; however, the findings of this review are limited by the bi-variate analyses presented in the majority of the included studies; hence, the impact of confounding is unclear. In

Key Findings: A total of 12 studies consisting of mostly cross-sectional analyses were included in this review. The majority of the studies documented the associations of dietary intake with total plasma or red blood cell VLCSFAs, in which a range of macronutrients and food groups were examined. Two cross-sectional analyses showed a consistent positive association between total fat and peanut intake and 22:0 and 24:0 and an inverse association between alcohol intake and 20:0 and 22:0. Furthermore, a moderate positive association between physical activity and 22:0 and 24:0 were observed. Lastly, there were conflicting results on the effects of smoking on VLCSFA. Most of the studies had a low risk of bias; however, the findings of this review are limited by the bi-variate analyses presented in the majority of the included studies; hence, the impact of confounding is unclear. In conclusion, although the current observational literature examining lifestyle determinants of VLCSFA is limited, existing evidence suggests that circulating 22:0 and 24:0 may be influenced by higher total and saturated fat consumption and nut intake.