Disclosures: The authors report no relevant financial disclosures.
Higher frequencies of adding salt to food were associated with premature mortality and lower life expectancy, according to study findings published in the European Heart Journal.
“The evidence in relation to sodium/salt intakes and mortality is still controversial,” Lu Qi, MD, PhD, FAHA, HCA Regents Distinguished Chair and professor in the department of epidemiology at Tulane University School of Public Health and Tropical Medicine, told Healio. “This study may motivate further investigations, which may provide evidence to affect the recommendation of adding salt.”
In a population-based cohort study, Qi and colleagues observed the UK Biobank in which participants were recruited in a baseline survey from 22 assessment centers throughout England, Wales and Scotland from 2006 to 2010.
Compared with participants with lower frequency of adding salt to foods, participants with higher frequency were more likely to be men, to be “non-white,” and to have a higher BMI and Townsend deprivation index. They were also less likely to have a healthy lifestyle. They had a higher prevalence of diabetes and CVD but a lower prevalence of hypertension and chronic kidney disease, according to the study. Higher frequency was also associated with higher intake of red meat and processed meat but lower intake of vegetables, fruits and fish, according to the authors.
Of 501,379 participants, 18,474 premature deaths were documented during a median of 9 years follow-up.
All-cause premature mortality among participants increased with frequency of adding salt. Compared with those who never or rarely added salt, elevated risk for premature mortality was present in the following groups: those who sometimes added salt (adjusted HR = 1.02; 95% CI , 0.99-1.06; P < .001), those who usually added it (aHR = 1.07; 95% CI, 1.02-1.11; P < .001) and those who always added it (aHR = 1.28; 95% CI, 1.2-1.35; P < .001).
Higher intake of fruits and vegetables, however, significantly modified the association of higher frequency of adding salt and all-cause premature mortality (P = .02), according to the study.
“We were surprised that high intake of fruits and vegetables may attenuate the adverse relation between adding salt and mortality,” Qi said.
Life expectancy for participants decreased with frequency of adding salt. For participants aged 50 years, women who always added salt had an average of 1.5 years lower life expectancy (95% CI, 0.72-2.3), whereas men who always added salt had 2.28 years lower (95% CI, 1.66-2.9) compared with the never/rarely group. At age 60 years, women who always added salt had an average of 1.37 years lower (95% CI, 0.66-2.09) and men who always added salt had an average of 2.04 years lower (95% CI, 1.48-2.59) life expectancy compared with those who never or rarely added salt.
“Reduction of the frequency of adding salt to foods can lower risk of premature mortality and increase life expectancy,” Qi said. “Clinical trials are needed to validate our findings.”
For more information:
Lu Qi, MD, PhD, FAHA, can be reached at firstname.lastname@example.org.