Study of 8,252 adults links cumulative BMI to faster cognitive decline

In a study analyzing data from 8,252 cognitively healthy participants tracked between 1996 and 2020 in the United States, researchers linked elevated cumulative body mass index to accelerated cognitive deterioration, according to findings published in the Journal of Neurology springer.comJournal of Neurologyspringer.comOpen source ↗. The cohort had a mean baseline age of 58.6 years, consisted of 58.3% women, and underwent an average follow-up of 17.5 years within the Health and Retirement Study framework.

Cumulative Metrics and Cognitive Assessment

The authors assessed cognitive health using a standardized composite score encompassing memory and executive function tests. Rather than relying on isolated measurements, they calculated cumulative BMI as the area under the curve over time, deriving the cumulative average BMI (caBMI) across the observation timeline. Linear mixed models adjusted for sociodemographic characteristics and baseline health status demonstrated that higher long-term weight burdens correlate with worsening mental performance over time.

Statistical analysis showed that a 100-unit increase in caBMI was significantly associated with faster decline rates across all tracked cognitive domains: global cognition decreased by -0.0030 standard deviations per year (95% CI: -0.0036 to -0.0024), executive function decreased by -0.0029 SD/year (95% CI: -0.0038 to -0.0021), and memory decreased by -0.0017 SD/year (95% CI: -0.0023 to -0.0011), with all associations showing p < 0.001.

Time Window and Age Differences

Longitudinal modeling identified year eight of follow-up as the specific time point showing the strongest association between caBMI and accelerated decline in global cognition, memory, and executive function springer.comJournal of Neurologyspringer.comOpen source ↗. Subgroup analyses further revealed that the association between caBMI and greater cognitive decline was particularly pronounced in participants aged 65 years and older. The researchers concluded that monitoring longitudinal weight trajectories provides critical predictive insight for cognitive health evaluations.