Features of lipid metabolism in Arctic residents depending on ethnicity and lifestyle

Introduction: Metabolic adaptations can differ significantly among Arctic residents with different ethnicities, lifestyles and adherence to traditional diets. The objective of this study was to examine the status of saturated fatty acids (SFA) and triglycerides (TG), the variability of body mass index (BMI) among the Russian Arctic residents according to their ethnicity and lifestyle.
Methods: The study involved adult females and males living in the territories of the Russian Arctic. The participants were divided into three groups: indigenous reindeer herders leading a nomadic lifestyle (NIP), indigenous people leading a sedentary lifestyle (SIP) and the Caucasian population (CP). The content of SFAs (C6-C24) and metabolic characteristics was determined using gas chromatographic and spectrophotometric methods. The study also included a quantitative comparison of the consumption of certain categories of food products. To analyze data, we used the descriptive analyses by nonparametric methods, as well as multiple linear regression analysis.
Results: The study found that the Caucasian females had higher triglycerides levels (%u0440<0.001), higher total contents of long-chain SFAs (LCSFAs) (C13-C18) (%u0440=0.002) and that the SIP females had reduced contents of very-long-chain fatty acids (C20-C24) (%u0440=0.039). These changes were not statistically significant in the males, partly due to the almost identical levels of TG, C16:0 and C18:0 in the NIP and the CP. The content of medium-chain SFAs (MCSFAs) (C6-C12) was higher in the SIP (p<0.001 for females; %u0440=0.002 for males). The indigenous males tended to have a lower BMI compared to the Caucasian males, resulting in a lower prevalence of overweight or obesity: 49.3% in the NIP (%u0440=0.006) and 57.4% in the SIP versus 69.3% in the CP. In female participants, these frequencies did not differ - 64%, 65.4% and 66% respectively. The NIP and SIP groups had higher consumption of traditional, carbohydrate-rich, meat products and vegetable oils, the latter of which was positively associated with SFA content.
Conclusions: The study revealed the dependence of the studied parameters of lipid metabolism on ethnicity (indigenous vs. Caucasian) and lifestyle (nomadic vs. sedentary). The population metabolic variability consisted in the increase in the levels of LCSFAs and TG in the CP, reflecting, most likely, an imbalance in the processes of their accumulation and consumption with a predominantly western type of nutrition. Indigenous populations, despite changes in diet towards an increased consumption of carbohydrate-rich products, have preserved an adaptive metabolism with the predominant use of lipids as energy resources. Higher levels of MCSFAs in the SIP, less adherent to a traditional diet, compared to the NIP, may be compensatory, with a growing role of such fatty acids in energy consumption and thermogenesis.
Keywords: Arctic residents, BMI, Nenets, nomadic lifestyle, reindeer herders, saturated fatty acids, traditional diet, triglycerides.