A new study is revealing a surprising connection between obesity and the amount of gray and white matter in the brain. The researchers using MRI technology found a correlation between higher amounts of fat and lower brain volumes in certain areas.
Using MRI technology
"MRI has shown to be an irreplaceable tool for understanding the link between neuroanatomical differences of the brain and behavior," said study lead author Ilona A. Dekkers, M.D., from Leiden University Medical Center in Leiden, the Netherlands.
"Our study shows that very large data collection of MRI data can lead to improved insight into exactly which brain structures are involved in all sorts of health outcomes, such as obesity."
A growing body of research has associated obesity with dementia and accelerated cognitive decline. To evaluate this relationship further, the researchers analyzed brain imaging results from more than 12,000 participants in the UK Biobank study.
MRI techniques were used to evaluate both the neuron-rich gray matter and the white matter.
"We found that having higher levels of fat distributed over the body is associated with smaller volumes of important structures of the brain, including gray matter structures that are located in the center of the brain," Dr. Dekkers said.
Different for men and women
"Interestingly, we observed that these associations are different for men and women, suggesting that gender is an important modifier of the link between fat percentage and the size of specific brain structures."
Men had a lower gray matter volume overall while women only showed a significant negative association with the globus pallidus. For both men and women, however, higher total body fat percentage correlated with microscopic changes to the brain's white matter.
Still, the researchers emphasized that more work needs to be done to establish a true relationship between body fat and brain shrinkage as correlation does not necessarily mean causation. The study also did not look at different types of fats which Dr. Dekkers says may play a role in brain changes.
"For future research, it would be of great interest whether differences in body fat distribution are related to differences in brain morphological structure, as visceral fat is a known risk factor for metabolic disease and is linked to systemic low-grade inflammation," said the study's senior author, Hildo Lamb, M.D., Ph.D., director of the Cardio Vascular Imaging Group of Leiden University Medical Center.
The study is published in the journal Radiology.