High vs Low Salt Diet for High Blood Pressure

Recruiting in Palo Alto (17 mi)

+1 other location

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Waitlist Available

Sponsor: Vanderbilt University Medical Center

No Placebo Group

Trial Summary

What is the purpose of this trial?This trial will have participants follow different salt diets to see how their blood pressure changes. It focuses on middle-aged people from a previous study. Researchers believe that salt intake affects blood pressure through inflammation and want to understand this better.

Eligibility Criteria

This trial is for adults who have normal blood pressure or high blood pressure that's either untreated or controlled with up to three medications. Participants must not be on certain drugs like steroids, avoid anti-inflammatory meds, and can't have conditions like heart failure or severe allergies to food.

Inclusion Criteria

Potentially eligible individuals must consent to and be willing to adhere to the study protocol.

I am not on anti-HTN meds or I control my high blood pressure with up to 3 meds.

Exclusion Criteria

I am taking medication to manage my blood pressure.

I take 4 or more blood pressure medications, including a diuretic, but my blood pressure is still high.

Medical contraindications to foods, e.g. celiac disease, nut allergy, egg allergy, etc.

+7 more

Participant Groups

The CARDIA-Salt Sensitivity of Blood Pressure study tests how a person's blood pressure changes when they switch between diets with different salt levels. It aims to understand the body's inflammatory response to salt and its effect on blood pressure in middle-aged individuals.

2Treatment groups

Experimental Treatment

Group I: Low Salt Diet then High Salt DietExperimental Treatment2 Interventions

The low-salt diet is comprised of 7 days of freshly prepared frozen meals, snacks, and Na+ free water. All low-salt meals will be prepared in each site's Metabolic Kitchen, with standardization of diets across sites. The low-salt diet includes: 20 mEq Na+ (±2 mEq) (460 mg/day), 100 mEq potassium (±2 mEq), and 1,000 mg calcium (±50 mg). The high-salt diet will be achieved through the supplementation of each participant's usual diet with Na+ bullion packets (2 packets per day). This will increase Na+ intake by approximately 2,200 mg (≈100 mEq Na+) to a total greater than 5,000 mg Na+ per day based on prior estimates of Na+ intake (see section C1.2). In addition, 1,000 mg of calcium carbonate (provided via Tums tablets) will be taken daily on the high Na+ diet to reduce the potential impact of changes in calcium intake on blood pressure.

Group II: High Salt Diet then Low Salt DietExperimental Treatment2 Interventions

The high-salt diet will be achieved through the supplementation of each participant's usual diet with Na+ bullion packets (2 packets per day). This will increase Na+ intake by approximately 2,200 mg (≈100 mEq Na+) to a total greater than 5,000 mg Na+ per day based on prior estimates of Na+ intake (see section C1.2). In addition, 1,000 mg of calcium carbonate (provided via Tums tablets) will be taken daily on the high Na+ diet to reduce the potential impact of changes in calcium intake on blood pressure. The low-salt diet is comprised of 7 days of freshly prepared frozen meals, snacks, and Na+ free water. All low-salt meals will be prepared in each site's Metabolic Kitchen, with standardization of diets across sites. The low-salt diet includes: 20 mEq Na+ (±2 mEq) (460 mg/day), 100 mEq potassium (±2 mEq), and 1,000 mg calcium (±50 mg).