Macronutrients and Proteins in Cheese Reduce Acute Dietary Sodium‐induced Endothelial Dysfunction in the Cutaneous Microcirculation

Abstract

Chronic dairy consumption is associated with improved cardiovascular outcomes, but a high dietary sodium (Na) intake induces endothelial dysfunction, evidenced by reduced nitric oxide (NO)‐dependent vasodilation (VD). It is unclear if increased Na intake in dairy products (cheeses) may have a benefit over other Na sources due to the moderating actions of dairy macronutrients and proteins. We hypothesized that acute cheese ingestion would attenuate reductions in NO‐dependent VD observed with an equal dose of non‐dairy Na. On 4 separate days, subjects ingested 3 oz. cheddar cheese (560 mg Na), 2.3 oz pretzels (560 mg Na), 6 oz. cheddar cheese (1120 mg Na), or 4.6 oz pretzels (1120 mg Na). An intradermal microdialysis fiber was placed in the forearm skin of 7 subjects (60±2 years) for local delivery of Ringer's solution. Red cell flux was measured by laser‐Doppler flowmetry (LDF) during standardized local heating protocol (42°C). After cutaneous vascular conductance (CVC = LDF/MAP) plateaued, 20mM L‐NAME was perfused to quantify NO‐dependent VD. Data were normalized as %CVCmax (28mM SNP). The local heating plateau was not different between treatments. NO‐dependent VD was greater following cheese consumption compared to Na alone for both 560 mg Na (53±6 vs. 41±4%; p=0.06) and 1120 mg Na (54±7 vs. 38±4%; p=0.03). Na intake in dairy products (cheese) augmented NO‐dependent VD compared to Na ingestion alone, suggesting that macronutrients and proteins in cheese may reduce acute dietary Na‐induced endothelial dysfunction.