Abstract
Diet ranks among the most modifiable determinants of cardiovascular disease risk, yet the evidence base is vast, conflicting, and burdened by observational confounding. This narrative review synthesizes evidence on controversial dietary components and established heart-healthy dietary patterns. Moderate egg intake is acceptable within a high-quality dietary pattern; preparation method meaningfully modifies risk. Habitual moderate coffee consumption is neutral to modestly cardioprotective; unfiltered preparations elevate low-density lipoprotein cholesterol (LDL-C) through diterpene retention. No safe cardiovascular benefit threshold for alcohol can be established; binge drinking is consistently harmful. Low-carbohydrate and ketogenic diets improve select metabolic parameters but raise concern for sustained LDL-C and apolipoprotein B elevation, particularly with animal-derived macronutrient substitution. Omega-3 supplementation reduces coronary heart disease and myocardial infarction risk dose-dependently; atrial fibrillation risk is confined to high-dose formulations in high-risk populations. The Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets carry the most robust evidence for cardiovascular risk reduction; the Portfolio diet provides effective non-pharmacologic lipid lowering. Overall dietary pattern quality predicts cardiovascular risk more reliably than any single food or nutrient.