Sodium intake above recommended amount raises mortality risks in vulnerable populations

Key takeaways:

• A 1,000 mg increase in daily salt intake increased the risk for CHD death by 8% in Black individuals.
• Researchers suggested providing healthy diet resources and educating people about the harms of sodium.

Daily sodium intake above the recommended amount increased the risk for mortality from CVD and heart failure among historically underrepresented and underserved populations, a study showed.

According to Hyung-Suk Yoon, PhD, MPH, an assistant professor at the University of Florida, and colleagues, the 2020 to 2025 Dietary Guidelines for Americans recommend an intake of less than 2,300 mg of sodium per day, although most Americans exceed this amount by more than 1,000 mg.

“Epidemiologic evidence to date supports the mortality burden due to excessive sodium intake,” they wrote. “Nevertheless, this burden remains overlooked in marginalized populations, especially Black Americans and individuals with low socioeconomic status who consume more high-sodium foods than others.”

The researchers evaluated associations between sodium intake and several mortality outcomes — including all-cause, CVD, coronary heart disease (CHD), stroke and heart failure — using a sample from the Southern Community Cohort Study, which is composed of adults aged 49 to 79 years from 12 Southeastern states.

Among those in the cohort (n = 64,329), 71.8% were Black, 60.9% were women and 82.8% reported an annual household income of less than $25,000.

During a median follow-up of 13.8 years, there were 17,811 deaths, including 5,701 CVD deaths .

Overall, 81.2% and 79.5% of Black and white individuals exceeded the dietary recommendations, respectively.

Yoon and colleagues found that a 1,000 mg increase in daily sodium intake above the recommended amount among Black individuals was associated with a:

• 3% increased risk for death from all causes (HR = 1.03; 95% CI, 1.01-1.05);
• 7% increased risk for death from CVD (HR = 1.07; 95% CI, 1.03-1.1); and an
• 8% increased risk for death from CHD (HR = 1.08; 95% CI, 1.02-1.14).

Meanwhile, among white individuals, a 1,000 mg increase in daily sodium intake was associated with a:

• 8% increased risk for death from CVD (HR = 1.08; 95% CI, 1.02-1.14);
• 13% increased risk for death from CHD (HR = 1.13; 95% CI, 1.03-1.23); and a
• 55% increased risk for death from heart failure (HR = 1.55; 95% CI, 1.2-2.01).

The researchers also found that sodium intake above the recommended amount possibly accounted for 10% of total CVD deaths, 13% of total CHD deaths and 30% of heart failure deaths in the study population.

However, they noted that the observational study design prevented them from establishing a causal link between excessive sodium intake and cardiometabolic deaths. Additionally, sodium intake was measured only at baseline.

Yoon and colleagues explained that economic barriers such as food insecurity “are significant determinants of poor diet quality, including excessive sodium intake.”

“Providing accessible healthy diet resources and increasing knowledge on the potential harms associated with high sodium intake would be the first steps in reducing racial, ethnic, and socioeconomic disparities in everyday diets and health outcomes,” they wrote.