Water intake, hydration status and 2-year changes in cognitive performance: a prospective cohort study

Background Water intake and hydration status have been suggested to impact cognition; however, longitudinal evidence is limited and often inconsistent. This study aimed to longitudinally assess the association between hydration status and water intake based on current recommendations, with changes in cognition in an older Spanish population at high cardiovascular disease risk. Methods A prospective analysis was conducted of a cohort of 1957 adults (aged 55–75) with overweight/obesity (BMI between ≥ 27 and < 40 kg/m2) and metabolic syndrome from the PREDIMED-Plus study. Participants had completed bloodwork and validated, semiquantitative beverage and food frequency questionnaires at baseline, as well as an extensive neuropsychological battery of 8 validated tests at baseline and 2 years of follow-up. Hydration status was determined by serum osmolarity calculation and categorized as < 295 mmol/L (hydrated), 295–299.9 mmol/L (impending dehydration), and ≥ 300 mmol/L (dehydrated). Water intake was assessed as total drinking water intake and total water intake from food and beverages and according to EFSA recommendations. Global cognitive function was determined as a composite z-score summarizing individual participant results from all neuropsychological tests. Multivariable linear regression models were fitted to assess the associations between baseline hydration status and fluid intake, continuously and categorically, with 2-year changes in cognitive performance. Results The mean baseline daily total water intake was 2871 ± 676 mL/day (2889 ± 677 mL/day in men; 2854 ± 674 mL/day in women), and 80.2% of participants met the ESFA reference values for an adequate intake. Serum osmolarity (mean 298 ± 24 mmol/L, range 263 to 347 mmol/L) indicated that 56% of participants were physiologically dehydrated. Lower physiological hydration status (i.e., greater serum osmolarity) was associated with a greater decline in global cognitive function z-score over a 2-year period (β: − 0.010; 95% CI − 0.017 to − 0.004, p-value = 0.002). No
CIBER Fisiopatologia de la Obesidad y Nutricion (CIBEROBN)
Instituto de Salud Carlos III (ISCIII), through the Fondo de Investigacion para la Salud (FIS)
European Commission PI13/00673 PI13/00492 PI13/00272 PI13/01123 PI13/00462 PI13/00233 PI13/02184 PI13/00728 PI13/01090 PI13/01056 PI14/01722 PI14/00636 PI14/00618 PI14/00696 PI14/01206 PI14/01919 PI14/00853 PI14/01374 PI14/00972 PI14/00728 PI14/01471 PI16/00473 PI16/00662
Especial Action Project entitled: Implementacion y evaluacion de una intervencion intensiva sobre la actividad fisica Cohorte PREDIMEDPlus grant
European Research Council (ERC) European Commission 340918
La Caixa Foundation 2013ACUP00194
Center for Forestry Research & Experimentation (CIEF) PROMETEO 17/2017
Juan de la Cierva-Incorporacion research grant of the Spanish Ministry of Economy, Industry and Competitiveness IJC2019-042420-I
European Social Fund (ESF)
EU-H2020 Grants Eat2beNICE/H2020-SFS-2016-2
Horizon 2020 PRIME study (Prevention and Remediation of Insulin Multimorbidity in Europe 847879
Canadian Institutes of Health Research (CIHR) MFE-171207
University of Rovira I Virgili 2020PMF-PIPF-37
Spanish Government FPU 17/01925
Conselleria de Innovacion, Ciencia y Sociedad Digital APOSTD/2020/164
Center for Forestry Research & Experimentation (CIEF)
European Social Fund (ESF) European Commission
Juan de la Cierva postdoctoral grant from Ministerio de Ciencia, Innovacion y Universidades
Hydration for Health 2022-08514
The European Regional Development Fund PI16/01873 PI16/01094 PI16/00501 PI16/00533 PI16/00381 PI16/00366 PI16/01522 PI16/01120 PI17/00764 PI17/01183 PI17/00855 PI17/01347 PI17/00525 PI17/01827 PI17/00532 PI17/00215 PI17/01441 PI17/00508 PI17/01732 PI17/00926
European Commission PI19/00957 PI19/00386 PI19/00309 PI19/01032 PI19/00576 PI19/00017 PI19/01226 PI19/00781 PI19/01560 PI19/01332 PI20/01802 PI20/00138 PI20/01532 PI20/00456 PI20/00339 PI20/00557 PI20/00886 PI20/01158
Junta de Andalucia PI0458/2013 PS0358/2016 PI0137/2018