Improved diet and reduced waist-to-hip ratio associated with better cognitive and mental health: JAMA

The main results were measures of cognitive performance, resting-state functional MRI for assessing hippocampus functional connectivity, and diffusion tensor imaging for assessing white matter structural connectivity. Cognitive tests and brain imaging were conducted at a mean (SD) age of 70 (5) years.

There were a total of 664 individuals in the final WHR sample and 512 participants in the final diet quality sample. Higher hippocampus functional connections to the occipital lobe and cerebellum, as well as greater white matter integrity as indicated by higher fractional anisotropy and lower diffusivity, were linked to improved food quality in midlife and from midlife to late age.

Higher midlife WHR was linked to reduced FA and higher MD and radial diffusivity in the corticospinal tract, which includes the cingulum and inferior longitudinal fasciculus and makes up 4.9% of the white matter skeleton. Diffusion acted as a partial mediating factor in the relationships among midlife WHR, working memory, and executive function.

Overall, it was discovered that midlife measurements of diet and abdomen fat (WHR intercepts) were linked to later-life hippocampus function and white matter connections. White matter diffusivity acted as a partial mediating factor in the link between higher WHR in midlife and worse working memory and executive function in later life.

Reference:

Jensen, D. E. A., Ebmeier, K. P., Akbaraly, T., Jansen, M. G., Singh-Manoux, A., Kivimäki, M., Zsoldos, E., Klein-Flügge, M. C., & Suri, S. (2025). Association of diet and waist-to-hip ratio with brain connectivity and memory in aging. JAMA Network Open, 8(3), e250171. https://doi.org/10.1001/jamanetworkopen.2025.0171