# Obesity accelerates brain ageing: a multimodal imaging study

## TL;DR

Obesity may speed up brain aging, with effects most noticeable in midlife, suggesting early interventions could help prevent brain-related issues later in life.

## Contribution

This study provides empirical evidence that obesity accelerates brain aging using multimodal neuroimaging and machine learning.

## Key findings

- Obese individuals showed greater brain age delta compared to normal-weight individuals in grey matter and functional connectivity.
- The brain aging effect was most pronounced in midlife for grey matter and after age 60 for functional connectivity.
- Early intervention on obesity may help maintain brain health and reduce late-life brain-related risks.

## Abstract

Obesity is a global health concern, and it is thought to accelerate the normal ageing process. Obesity has also been linked to neurodegenerative processes, possibly as a manifestation of accelerated brain-ageing. In this cross-sectional study we combined multimodal neuroimaging data and machine learning techniques to assess the discrepancy between brain-based predicted age and chronological age, known as brain age delta, in obese participants and in normal-weighted individuals using a tight matching for age, gender and education across groups. Data were taken from the publicly available dataset ‘The Cambridge Centre for Ageing and Neuroscience (Cam-CAN)’ covering the adult lifespan (18–90 years old). Overall, brain age delta was greater in obese individuals for grey matter (GM) and functional connectivity (intra- and inter-network connectivity) measures. When considering the age-range, the difference between groups peaked in mid-age (40–60 years old) for GM, while for intra-network connectivity it was more marked in late age (60–90 years old). Overall, our results provide evidence to the hypothesis that obesity accelerates the brain ageing process, with the earliest effect already evident in the 40–60 age range. Earlier intervention on obesity might contribute to maintain a healthy brain potentially reducing the risk of developing late-life brain-related pathologies.

The impact of obesity on brain ageing was investigated using multimodal neuroimaging and machine learning. Accelerated brain ageing was observed in obese relative to normal-weight individuals, peaking in midlife for grey matter and after 60 for functional connectivity measures. Early interventions for obese to maintain brain health is warranted.

Graphical Abstract