Dietary Quality Along a Plant-Based Continuum: The Role of Added Salt, Oil, and Sugar in Chronic Disease Risk

Chronic noncommunicable diseases, including cardiovascular disease (CVD), type 2 diabetes (T2D), and cancer, constitute leading causes of global mortality, with suboptimal diet identified as a primary modifiable risk factor. Plant-based dietary patterns (PBDPs) can be conceptualized along a continuum of quality, with whole-food PBDPs consistently linked to lower risks of CVD, T2D, and all-cause mortality, though much of this evidence derives from studies of vegan or healthy plant-based dietary index patterns rather than whole-plant-food diets directly. Evidence further indicates that minimizing or eliminating added salt, oil, and sugar (SOS) within whole-food PBDPs may provide additional cardiometabolic benefits, primarily by favorably modifying three graded intermediate biomarkers: low-density lipoprotein cholesterol (LDL-C), blood pressure (BP), and adiposity. Dietary sodium increases BP in a linear, dose-dependent manner and enhances food palatability, potentially promoting passive overconsumption and increased adiposity. Although added oil is preferable to saturated fat for LDL-C reduction, preliminary evidence suggests that adding olive oil to an already oil-restricted whole-food PBDP may reduce its LDL-C and body-weight benefits; these findings are hypothesis-generating and require confirmation in larger, longer-term trials. Whole-food fat sources such as nuts and seeds may offer cardiovascular benefits at least equivalent to those of oils, without this attenuating effect. Added sugar promotes excess caloric intake, contributing to increased adiposity, and may impair insulin sensitivity; these effects are most clearly and consistently established for sugar-sweetened beverages (SSBs), whereas the evidence for solid added sugars is weaker and may depend more on excess energy intake and broader dietary context. This narrative review synthesizes evidence from systematic reviews, meta-analyses, Mendelian randomization studies, and key clinical trials to evaluate whether whole-food PBDPs minimizing or eliminating SOS may provide incremental benefit for chronic disease risk reduction and management compared to whole-food PBDPs that include these additives. Direct long-term randomized evidence comparing SOS-restricted to SOS-inclusive whole-food PBDPs remains limited, and the possible incremental benefit of SOS restriction within an already health-promoting dietary pattern warrants further investigation. Complete SOS elimination has not yet been shown to provide incremental benefit beyond a high-quality PBDP, and any benefit is likely greatest in individuals with hypertension, obesity, elevated cardiometabolic risk, or high baseline SOS intake.