[Increased mortality on a daily salt intake below six grammes]

Area of Science:

• Cardiovascular Health
• Public Health Policy
• Nutritional Science

Background:

• Randomized controlled trials (RCTs) in healthy individuals demonstrate that reduced dietary salt intake (SR) has a negligible effect on blood pressure (BP), typically less than 1 mmHg.
• Current public health strategies often rely on computer modeling that extrapolates BP effects from hypertensive individuals to simulate mortality benefits of SR.
• This approach contrasts with observational studies indicating that low salt intake is associated with a significant increase in mortality (approximately 15%) in both healthy and hypertensive populations.

Purpose of the Study:

• To evaluate the discrepancy between simulated mortality benefits of salt reduction and real-world observational data.
• To assess the public health implications of current salt reduction recommendations based on conflicting evidence.

Main Methods:

• Analysis of existing randomized controlled trials (RCTs) on salt intake and blood pressure in healthy individuals.
• Comparison of simulated mortality data derived from blood pressure changes with findings from observational studies on salt intake and mortality.
• Review of public health modeling assumptions regarding the impact of salt reduction.

Main Results:

• RCTs show minimal blood pressure reduction (<1 mmHg) in healthy individuals with reduced salt intake.
• Observational studies consistently report a 15% increased mortality risk associated with low salt intake in both healthy and hypertensive individuals.
• Computer modeling for public health often overestimates the benefits of salt reduction by using data from hypertensive populations.

Conclusions:

• The minimal blood pressure effects of salt reduction in healthy individuals do not support its widespread implementation as a public health priority.
• Observed increases in mortality linked to low salt intake challenge the validity of current public health simulations.
• Public health strategies concerning salt intake require re-evaluation based on comprehensive evidence from both experimental and observational studies.