A Clinician's Guide for Trending Cardiovascular Nutritional Controversies in 2026

Although the broad outlines of a healthy diet are clear, controversy has arisen surrounding certain foods and nutrients. This review updates contemporary nutrition controversies and the extent to which they may promote or protect against cardiovascular disease (CVD). In this review, beef tallow, ultraprocessed foods, full-fat dairy, seed oils, medium chain triglyceride oils, seafood, and alternative sweeteners are considered. Three groupings included: 1) evidence of harm with a recommendation to limit or avoid; 2) lacking in evidence for harm or benefit; and 3) evidence of benefit. The evidence of harm category included beef tallow, due to association with increased low-density lipoprotein cholesterol, ultraprocessed foods associated with worsened cardiometabolic health, and artificial sweeteners owing to correlations with increased CVD. Within the category lacking in evidence were full-fat dairy, medium chain triglyceride, monk fruit, and stevia. Finally, evidence of benefit included seed oils and seafood based on improved CVD outcomes.