Genomics, Environmental Factors and Social Determinants of Cardiovascular Disease in African Americans Study (GENE-FORECAST): Sodium Intervention Trial (SIT)

Background: Hypertension is a risk factor for heart disease. Low-sodium diets rich in fruits, vegetables, and other healthy foods are a good way to reduce blood pressure in people with hypertension. Researchers want to learn more about why African Americans seem to have the greatest benefit from certain dietary interventions. Objective: To better understand the body's response to adding more salt to the diet. Eligibility: U.S.-born African American adults ages 21 to 65 who are in good general health and took part in the GENE-FORECAST. Design: Participants will be screened with a medical history and physical exam. If needed, they will take a pregnancy test. These tests will be repeated during the study. Each day for 2 weeks, participants will take 3 capsules that contain either placebo or salt. Then they will take no pills for 3 weeks. Then they will take placebo or salt capsules for 2 more weeks. Participants will talk about the foods and drinks they have consumed over the past 24 hours. They will take a survey about their physical activity and sleep. Participants will complete taste tasks to obtain their responses to sweetness or saltiness. Sucrose and salt detection thresholds and preferences will be assessed. Participants will give blood and urine samples. Saliva samples will be collected from their mouth by passive drool or by spitting into a sterile tube. Skin samples will be collected from behind their ears and the inner part of their elbow, using sterile swabs. Participants will get kits to collect stool samples at home. Participants will have 4 study visits over 7 weeks.