The goal of this clinical trial is to determine if a high potassium intake can counteract the harmful effects of excess sodium on endothelial function in older adults with no history of cardiometabolic disease. The main questions it aims to answer are:
1. Can a high potassium intake attenuate dietary sodium-induced endothelial dysfunction in older adults.
2. Do changes in endothelial function in response to alterations in sodium and potassium intake differ by sex.
Participants will participants will consume three controlled diets for 10 days each with a minimum 14-day washout between interventions. The order in which participants consume the diets will be randomized. The study diets will vary in sodium and potassium content. Measures of cardiovascular health (blood pressure, arterial stiffness, endothelial function) will be assessed at the end of each diet.