Effects on blood pressure of a decrease in sodium use in institutional food preparation: the Exeter-Andover Project

Area of Science:

• Nutrition Science
• Cardiovascular Health
• Public Health

Background:

• High sodium intake is a risk factor for hypertension.
• Essential hypertension often develops during youth.
• Dietary habits established in adolescence can persist into adulthood.

Purpose of the Study:

• To assess the impact of reduced sodium intake on blood pressure in adolescents.
• To evaluate the feasibility of implementing dietary changes in school settings.
• To determine the potential of modest sodium reduction in preventing future hypertension.

Main Methods:

• A controlled intervention study was conducted in two boarding high schools.
• Sodium intake was reduced by 15-20% through modifications in food procurement and preparation.
• Blood pressure was monitored in students (n=341 control, n=309 intervention) over one-year periods with schools alternating roles.

Main Results:

• Dietary intervention resulted in a statistically significant reduction in systolic blood pressure (-1.7 mmHg) and diastolic blood pressure (-1.5 mmHg).
• The observed changes in blood pressure were significant (p=0.003 for systolic, p=0.002 for diastolic).
• No changes in students' usual eating habits were required.

Conclusions:

• Modest and achievable reductions in dietary sodium can effectively lower blood pressure in adolescents.
• Implementing such dietary changes in schools is a viable strategy for public health.
• Sustained reduction in sodium intake may significantly decrease the future risk of essential hypertension among young individuals.