The association of sodium intake with successful aging, in 3,349 middle-aged and older adults: Results from the ATTICA and MEDIS cross-sectional epidemiological studies

BACKGROUND: The association between sodium intake and successful aging is not elucidated to date. OBJECTIVE: To evaluate the association between sodium intake and successful aging, in people aged >50 years, living in Greece. METHODS: A cross-sectional study was conducted in middle aged and older adult participants of the ATTICA (n = 1,128) and MEDIS (n = 2,221) epidemiological studies. Anthropometric, clinical, socio-demographic and lifestyle characteristics derived through standard procedures and questionnaires. Sodium intake was measured based on the USDA Food Composition database; table salt or salt from processed foods were not evaluated. Successful aging was assessed using the Successful Aging Index (SAI, range 0-10, higher values indicating higher successful aging) comprising of health-related, social, lifestyle and clinical characteristics. RESULTS: Participants with ≥1500 mg/day sodium intake had 20.2% on average lower SAI score compared to those with <1500 mg/day sodium intake; stratification by sex and age revealed that in both females and males high sodium intake (≥1900 mg/day) was also inversely associated with SAI compared to low sodium intake (<1300 mg/day); this association was more evident among older males (high vs. low: >70-males/>70-females, -90% vs. 82.5%, p < 0.001) and overweight/obese participants (high vs. low: overweight/obese/normal weight, -59% vs. -35%, p's < 0.05). CONCLUSIONS: Daily sodium intake of <1500 mg seems to be a key factor for achieving successful aging. Public health nutrition policies should enforce their actions on reducing sodium intake by people of all ages.