High BMI linked to reduced brain volume and increased white matter lesions, study finds

A recent study published in Health Data Science, a Science Partner Journal, revealed the significant impact of high cumulative body mass index (BMI) on brain health

The research, led by Associate Professor Han Lv from Beijing Friendship Hospital, Capital Medical University, found that high BMI is associated with smaller brain volume, larger white matter lesions, and abnormal microstructural integrity.

The health burden of overweight and obesity has substantially increased over the last two decades. Characterized by high body mass index (BMI), overweight and obesity are associated with poorer brain health, resulting in accelerated cognitive decline and dementia.

Several cross-sectional studies that acquired BMI and neuroimaging data simultaneously have found that individuals with high BMI had smaller brain volumes and altered white matter (WM) integrity. Several previous studies have analysed the effect of BMI on features of the brain, but the number of neuroimaging features was limited.

In the study, researchers analysed data from a 16-year population-based cohort to investigate the effects of cumulative BMI on neuroimaging features in adults aged 25 to 83 years and discovered that high BMI was linked to smaller brain volume and larger volumes of white matter hyperintensity (WMH), particularly in adults younger than 45 and those older than 60.

The study utilized a generalized linear model to evaluate the association between cumulative BMI and various neuroimaging features, including brain macrostructure, white matter integrity, and brain microstructure.

The results indicated that high BMI is causally linked to smaller grey matter volume and increased fractional anisotropy, a useful measure of connectivity in the brain, in certain brain regions, highlighting the importance of maintaining a healthy BMI throughout adulthood to preserve brain health.

“High cumulative BMI is detrimental to brain health, especially for younger adults under 45 years, where it corresponds to approximately 12 years of brain aging. Maintaining a BMI below 26.2 kg/m² is suggested for better brain health. This research provides crucial insights into the relationship between BMI and brain health, emphasizing the need for public health strategies to control BMI for better neurological outcomes,” concluded Associate Professor Han.

Reference: Han Lv, Na Zeng, Mengyi Li, Jing Sun, Ning Wu, Mingze Xu, Qian Chen, Xinyu Zhao, Shuohua Chen, Wenjuan Liu, et al. Association between Body Mass Index and Brain Health in Adults: A 16-Year Population-Based Cohort and Mendelian Randomization Study. Health Data Sci. 2024;4:0087.DOI:10.34133/hds.0087