Oat-Protein-Based Diet Lowers Blood Pressure and Prevents Cardiac Remodeling and Dysfunction in Spontaneously Hypertensive Rats

Background/Objectives: Hypertension and its associated complications, such as cardiac remodeling and dysfunction, continue to impose a significant burden on global healthcare. Nutritional interventions have been recognized as playing a crucial role in addressing this devastating condition termed a ‘silent killer’. Plant-based proteins could potentially be utilized as a non-pharmacological strategy to combat hypertension and its related risk factors. In this study, we investigated the efficacy of an oat protein diet in managing hypertension and cardiac abnormalities. Methods: Four-week-old male spontaneously hypertensive rats (SHRs) and Wistar–Kyoto (WKY) rats were fed a regular diet with casein as a protein source or an oat-protein-based diet for 16 weeks. Twenty-week-old male SHRs showed high blood pressure (BP), cardiac remodeling, cardiac dysfunction, higher levels of markers of oxidative stress [malondialdehyde (MDA)] and inflammation [tumor necrosis factor-α (TNF-α)], as well as lower levels of a marker of vascular function (nitric oxide). Results: The oat protein diet was able to significantly lower high BP, prevent cardiac remodeling and dysfunction, improve the levels of nitric oxide, and reduce the levels of TNF-α. Oat protein, after in vitro gastrointestinal digestion, also exhibited angiotensin-converting enzyme inhibition and significantly higher antioxidant activity than casein when assessed with the 2,2-diphenyl-1-picrylhydrazyl and the iron-chelating assays in vitro. Conclusions: oat protein lowers BP and prevents cardiac remodeling and dysfunction partly via improving the levels of nitric oxide and TNF-αin SHRs. Its high antioxidant potential could contribute to the observed cardiovascular effects.