Study Finds Swapping Butter for Plant-Based Oils May Lower Heart Disease and Diabetes Risk

Switching from a diet high in saturated animal fats to one rich in plant-based unsaturated fats can significantly alter blood fat composition.

Recent research published in Nature Medicine revealed that diets abundant in plant-based unsaturated fats, as opposed to saturated animal fats, are linked to lower rates of type 2 diabetes and cardiovascular disease.

The World Health Organization advises that lowering saturated fat intake can decrease LDL cholesterol and improve heart health. Replacing saturated fats with polyunsaturated or monounsaturated fats from plant-based sources may reduce coronary heart disease risk.

The Dietary Guidelines recommend that less than 10 percent of daily calories come from saturated fats, yet 70-75 percent of adults exceed this limit.

Foods like deli sandwiches, and burgers are major sources of saturated fats and often lack nutrient density. The guidelines suggest swapping saturated fats for unsaturated fats, such as using nuts, seeds, or avocado instead of cheese, and choosing cooking oils high in polyunsaturated and monounsaturated fats instead of butter.

For the study, researchers analyzed blood fats and examined data from a subset of 113 participants from the DIVAS trial, a dietary intervention randomized control trial.

One group consumed a diet high in saturated animal fats for 16 weeks, while the other two groups consumed diets higher in monounsaturated or polyunsaturated plant-based fats. Participants also provided blood samples. Using blood lipid data from the DIVAS trial, researchers developed a scoring system to summarize the effects of replacing saturated fats with unsaturated fats on 45 lipid metabolite concentrations. This scoring system, the MLS score, assessed the impact of dietary fat quality on blood lipids and health outcomes.

The analysis revealed that participants with higher MLS or rMLS scores, indicating a diet rich in beneficial fats, had a significantly reduced risk of developing cardiometabolic diseases compared to their peers. Specifically, a higher MLS score was associated with a six-fold stronger reduction in heart disease risk (32% vs. 5%) and a five-fold stronger reduction in type 2 diabetes risk (26% vs. 5%).

“Fats and the foods containing them greatly impact heart health. Plant-based fats are typically found in nutrient-rich foods high in micronutrients, antioxidants, and anti-inflammatory compounds. In contrast, animal-based saturated fats and proteins increase inflammation, raising the risk of heart disease, stroke, type 2 diabetes, and certain cancers. The healthiest plant-based oils are monounsaturated, such as olive, avocado, peanut, and grapeseed oils. Other healthy unsaturated oils include walnut, flax, and hemp oils,” said the authors.

Reference: Eichelmann, F., Prada, M., Sellem, L. et al. Lipidome changes due to improved dietary fat quality inform cardiometabolic risk reduction and precision nutrition. Nat Med (2024). https://doi.org/10.1038/s41591-024-03124-1