Monounsaturated Fatty Acids in Cardiovascular Disease: Intake, Individual Types, and Content in Adipose Tissue as a Biomarker of Endogenous Exposure

Abstract

Unhealthy dietary patterns are a major modifiable risk factor for atherosclerotic cardiovascular disease (ASCVD). International guidelines recommend reducing saturated fatty acid intake while increasing polyunsaturated and monounsaturated fatty acids (MUFAs) to mitigate cardiovascular risk. However, evidence regarding MUFAs and risk of ASCVD remains conflicting, with recent studies raising concern about a potential higher risk associated with MUFA intake. The aim of this narrative review is to provide an overview of current knowledge and gaps in the literature regarding MUFAs and the risk of ASCVD with a focus on intake, individual types, and content in adipose tissue as a biomarker of endogenous exposure. Main findings reveal that most studies have inappropriately combined all MUFAs together, despite individual MUFA types having different biological effects and showing varying correlations between dietary intake and adipose tissue content. Adipose tissue composition may serve as a biomarker of long-term MUFA exposure, reflecting cumulative intake over one to two years while minimizing biases inherent in dietary assessments. However, tissue levels reflect both dietary intake and endogenous synthesis, complicating interpretation. Importantly, the source of MUFAs appears critical, with plant-derived MUFAs potentially offering advantages over animal-derived sources. In conclusion, we suggest that future research should focus on individual MUFA types rather than treating them as a homogeneous group, investigate their specific dietary sources and associations with ASCVD risk, and use adipose tissue biomarkers to improve exposure assessment and clarify causal relationships while considering overall dietary patterns.

Keywords: adipose tissue; atherosclerotic cardiovascular disease; diet; dietary patterns; endogenous exposure of MUFA; monounsaturated fatty acids.

Figure 1

Intake of selected foods according to the intake of MUFA (A) and adipose tissue content of MUFA (B) in the highest and lowest quintiles, respectively. Intake of foods and MUFA intake was energy-adjusted using the residual method. The radar plots show the underlying dietary pattern according to levels of MUFA indexed to the overall median. The radar plots are based on data from 3559 individuals in the Diet, Cancer, and Health cohort [43].

Figure 2

A simplified overview of the endogenous production and metabolism of MUFAs. Abbreviations: MUFAs = Monounsaturated fatty acids, PUFA = Polyunsaturated fatty acids, SCD1 = stearoyl-CoA desaturase 1, ELOVL5 = fatty acid elongase 5, Δ6D = Δ-6-desaturase.