A high body mass index (BMI) has a negative impact on brain health. Among other things, a high BMI is associated with smaller brain volume and larger lesions of the white matter, which plays an important role in the smooth functioning of the brain and the entire nervous system.
A recent study examined the effects of cumulative BMI on so-called neuroimaging characteristics of brain health in adult participants. The results are published in the English-language journal “Health Data Science”.
High BMI, lower brain volume
The researchers examined the association between BMI and brain health in adults aged 25 to 83 using two samples that combined BMI data from 681,275 people and neuroimaging data from 33,224 people.
The experts found that a high BMI was associated with smaller brain volume and a larger volume of white matter hyperintensity, particularly in adults younger than 45 or older than 60 years.
The white matter is associated with various cognitive functions, such as memory and attention, the researchers explain.
“High cumulative BMI has detrimental effects on brain health, especially in younger adults under 45 years of age, where it corresponds to about 12 years of brain aging,” emphasizes study author Han Lv in a new press release.
How high should the BMI be?
The results suggest that a healthy BMI is beneficial for brain health and especially for brain aging. “It is recommended to maintain a BMI below 26.2 kg/m² to improve brain health,” adds the doctor.
A generalized linear model was used to evaluate the association between cumulative BMI and various neuroimaging features, the team reports. These included brain macrostructure, white matter integrity and brain microstructure.
In addition, a Mendelian randomization analysis was performed to identify possible causal relationships, the experts add.
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Healthy BMI for a healthy brain
The results show, according to the researchers, that a high BMI is associated with a lower volume of gray matter and an increased so-called fractional anisotropy in certain brain regions.
“This research provides important insights into the relationship between BMI and brain health and highlights the need for public health strategies to control BMI to achieve better neurological outcomes,” adds study author Lv.
The study shows that a healthy body weight and a normal BMI are not only important for the body, but also have a significant impact on brain health. (as)