Excessive dietary salt intake can harm cognition in older adults, according to a prospective, population-based cohort study in the Shandong area of the People’s Republic of China.
Led by Weike Liu, MM, of Wenzhou Medical University, researchers measured the urinary sodium concentration of 2,041 randomly selected individuals aged 60 and older for seven consecutive days, then classified them into four salt intake groups: low (six or fewer grams daily), mild (more than six to nine grams daily), moderate (more than nine but fewer than 12 grams daily), and high (12 or more grams daily).
Scores on the Mini-Mental State Examination, Montreal Cognitive Assessment, and Dementia Rating Scale decreased in all four salt intake groups, the researchers said. However, the decrease was significantly greater in the- high-intake group compared with the other groups. The moderate group also had a significant decrease compared with the low-intake and mild-intake groups.
Over the 11-year follow-up period, 319 individuals (13.74 per 1,000 person-years) developed cognitive impairment: 21 (5.34) in the low-intake group, 63 (9.52) in the mild-intake group, 100 (14.94) in the moderate-intake group, and 135 (22.61) in the high-intake group, the researchers said.
Compared with individuals in the low salt intake group, the risk of cognitive impairment was 75% greater in the mild-intake group, 180% greater in the moderate-intake group, and 330% greater in the high-intake group, the researchers found. There was a 59% increased risk of cognitive impairment for each standard deviation rise in salt intake across the entire follow-up period.
Excessive salt intake increased dementia risk even after they adjusted for other risk factors, such as hypertension and the presence of the apolipoprotein E (APOE) genotype, the researchers said.
Source: Liu W, et al. Excessive Dietary Salt Intake Exacerbates Cognitive Impairment Progression and Increases Dementia Risk in Older Adults [published online: November 6, 2022]. J Am Med Dir Assoc. DOI: https://doi.org/10.1016/j.jamda.2022.10.001.