The impact of dietary acid load on super-agers with exceptional cognitive abilities: a propensity score analysis of national health and nutrition examination survey (NHANES) 2011–2014

Objectives 'Super-agers,' individuals over 80 with memory abilities comparable to those 20–30 years younger. The relationship between super-agers and dietary acid load (DAL) is an area that warrants further investigation. We aim to examine the link between DAL and super-agers and assess DAL's effects on cognitive functions across different age groups and cognitive domains. Design Employing a cross-sectional analysis of the 2011–2014 National Health and Nutrition Examination Survey (NHANES) data, we utilized propensity score analysis and multivariate-adjusted regression to mitigate confounding factors. Setting Older adults aged 60 and above in the United States. Participants Our primary analysis encompassed 985 older adults, supplemented by a sensitivity analysis with 2,522 participants. Measurements DAL was assessed through potential renal acid load (PRAL), estimated net acid excretion (NAEes), and net endogenous acid production (NEAP) indices. Results Super-agers demonstrate a preference for alkaline diets, shown by their lower DAL indices. After inverse probability of treatment weighting (IPTW), multivariate-adjusted logistic regression reveals that each unit reduction in NAEes and PRAL increases the chances of being a super-ager by 3.9% and 3.0%, respectively. The DAL's impact on cognitive function becomes more pronounced with age. Lower PRAL and NAEes scores are significantly linked to higher situational memory and overall cognitive performance scores in those over 70, with these effects being even more pronounced in participants over 80. Conclusion This research pioneers in demonstrating that super-agers prefer an alkaline diet, highlighting the potential role of alkaline diet in countering cognitive decline associated with aging.