Plant-based fats outperform dairy fats in reducing heart disease and diabetes risks

By Tarun Sai LomteReviewed by Susha Cheriyedath, M.Sc.Sep 2 2024

Research Briefing: Blood lipid profiling indicates that dietary fat quality is associated with cardiometabolic risk. Image Credit: Oksana Mizina / Shutterstock

Groundbreaking lipid profiling uncovers how plant-based fats dramatically enhance heart and metabolic health, paving the way for precise dietary interventions.

A recent research briefing published in the journal Nature Medicine reported associations between dietary fat quality and cardiometabolic risk.

The World Health Organization (WHO) ranks the evidence for the health benefits of substituting specific nutrients for others (e.g., mono- and poly-unsaturated fats for saturated fat) as low to moderate. According to the WHO, the current dietary guidelines advocating for reduced consumption of saturated fats are based on evidence of moderate certainty but remain a topic of ongoing debate.

Besides, the main drawbacks of existing intervention trials assessing different dietary fat types are shorter durations and reliance on indirect measures, e.g., cholesterol, instead of clinical endpoints (incident type 2 diabetes or cardiovascular events). Furthermore, observational studies evaluating the health outcomes of lower saturated fat intake are prone to confounding and often do not report the effects of specific nutrient substitutions.

The study and findings

In the present briefing, researchers utilized extensive blood fat composition profiling in different types of studies and observed associations between dietary fat quality and cardiometabolic risks. They combined data from dietary intervention studies that precisely controlled the types and sources of dietary fats with long-term observational studies that monitored disease occurrence over extended periods.

The researchers conducted extensive blood lipid profiling and developed/validated a multi-lipid score (MLS). The score reflected the effects of an intervention on the concentrations of 45 lipid metabolites, serving as a surrogate for metabolic adaptation to dietary fat changes. This approach allowed them to evaluate the implications of altering dietary fat quality on cardiometabolic health more precisely. The team leveraged the MLS to assess the implications of changes in the quality of dietary fats on cardiometabolic health in population studies.

Further, subgroup-specific effects were analyzed in a long-term intervention trial. The differences in MLS, which aligned with the impact of substituting saturated dairy fat with plant-based unsaturated fat, were associated with a significantly lower incidence of type 2 diabetes (in a dietary intervention trial) and cardiovascular disease (in prospective cohort studies).

Persons with initially worse MLS exhibited a stronger decrease in diabetes risk when on a Mediterranean diet rich in plant-based unsaturated fats than those with favorable MLS. This finding highlights the importance of the initial metabolic state in determining the effectiveness of dietary interventions. Substituting saturated fats from dairy products, e.g., butter, with plant-based unsaturated fats could result in substantially reduced cardiometabolic risks.

Conclusions

The study contributes important evidence supporting the current guidelines on the optimal source and quality of dietary fat but also underscores ongoing debates and limitations in the existing evidence base.  The researchers addressed previous limitations of evidence underlying these guidelines by integrating randomized controlled trials and observational studies. The findings highlight the cardiometabolic benefits of replacing saturated fat from dairy products with unsaturated fat from plant products.

The authors said, “The enthusiasm our work has generated encourages us to apply omics profiles for integrating data from cohorts and trials to other nutrition research questions.” However, they cautioned that their multi-study strategy is not without limitations.

While this multi-study approach addressed previous research biases, the team did not perform independent studies to establish thresholds for decision-making, examine cost-effectiveness, and validate absolute effect sizes on all metabolites. However, they cautioned that their multi-study strategy is not without limitations.

Additionally, the observed associations need validation in diverse racial and ethnic groups, as the study populations were primarily of European descent. Overall, the findings open avenues for more precise targeted interventions of dietary fat quality through lipid profiling. However, the application of lipidomics scores for dietary risk prevention requires further validation in future randomized controlled trials, particularly in more diverse populations.