Dietary fat intakes and cardiovascular disease risk in adults with type 2 diabetes: a systematic review and meta-analysis

Purpose Advice regarding the intake of dietary fats is particularly relevant to those with type 2 diabetes, given their increased risk of cardiovascular disease. Methods We have undertaken a systematic review of fat intakes and cardiovascular disease risk in adults with type 2 diabetes using an online search strategy to 24 April 2020, augmented with hand searching. Searches, extraction, and risk of bias assessments were undertaken by two researchers. The quality of evidence was assessed with GRADE protocols. Results We identified five eligible prospective studies of 22,591 participants followed for on average 9.8 years, and one trial of 14 participants with type 2 diabetes. Limited data were available; however, replacement analyses of saturated fat with polyunsaturated fat (RR for 2% energy replacement 0.87 95% CI: 0.77–0.99) or carbohydrate (RR for 5% energy replacement 0.82 95% CI: 0.67–1.00) was associated with reduced cardiovascular disease occurrence. Higher polyunsaturated: saturated fat intake was also associated with reduced cardiovascular disease occurrence (RR 0.75 95% CI: 0.57–0.98). The quality of evidence was low to very-low. Conclusion Although only limited data were available, replacement of saturated fats with other macronutrients, such as polyunsaturated fats, was associated with reduced cardiovascular disease occurrence. Supporting evidence from research in the general population increases confidence in these findings. Until more data are available to better comment on dietary fat intakes in cardiovascular disease risk of those with type 2 diabetes, it appears appropriate that saturated fats be replaced in the diet with other macronutrients, such as polyunsaturated fats.