Monounsaturated fatty acids from plant or animal sources and risk of type 2 diabetes in three large prospective cohorts of men and women

Abstract

Aims/hypothesis

Existing evidence on the relationship between intake of monounsaturated fatty acids (MUFAs) and type 2 diabetes is conflicting. Few studies have examined whether MUFAs from plant or animal sources (MUFA-Ps and MUFA-As, respectively) exhibit differential associations with type 2 diabetes. We examined associations of intakes of total MUFAs, MUFA-Ps and MUFA-As with type 2 diabetes risk.

Methods

We used data from 51,290 women in the Nurses’ Health Study (1990–2016), 61,703 women in the Nurses’ Health Study II (1991–2017) and 29,497 men in the Health Professionals Follow-up Study (1990–2016). Using food frequency questionnaires and food composition tables, we calculated MUFA-P and MUFA-A intakes every 4 years and modelled their associations with type 2 diabetes using Cox regression models.

Results

During 3,268,512 person-years of follow-up, we documented 13,211 incident type 2 diabetes cases. After multivariate adjustment, total MUFA intake was associated with higher type 2 diabetes risk, with HR for Q5 vs Q1 of 1.10 (95% CI 1.01, 1.22). MUFA-Ps and MUFA-As demonstrated divergent associations, with HRs of 0.87 (95% CI 0.81, 0.94) and 1.34 (1.23, 1.45), respectively. In substitution analyses, HRs were 0.92 (95% CI 0.86, 0.99) for replacing 2% of energy from trans fatty acids or 0.72 (0.66, 0.78) and 0.82 (0.77, 0.88) for replacing 5% from MUFA-As and 5% from the sum of saturated fatty acids and MUFA-As with MUFA-Ps, respectively. Substituting MUFA-As for saturated fatty acids and refined carbohydrates was associated with a 43% and 33% higher risk, respectively.

Conclusions/interpretation

Higher intake of MUFA-Ps was associated with lower type 2 diabetes risk, whereas increased intake of MUFA-As was associated with higher risk. Replacing saturated fatty acids, trans fatty acids and MUFA-As with MUFA-Ps may be beneficial for type 2 diabetes prevention.

Graphical Abstract