Researchers are already well-aware how the size of the brain determines its general health and functionality. However, they lack knowledge about the factors that affect the size of the brain itself.
Existing studies have linked the shrinkage of the brain with an increased memory decline and an enhanced risk of acquiring dementia. However, the research on the effects of extra body fat on the brain size is not sufficient and the results remain to be inconclusive.
One recent study focusing on how the body fat affects brain size has been published in the journal named Neurology. This study has utilized a large sample size as compared to other studies on a similar topic.
The study took 9,652 people from the UK biobank with most of the people around 55 years of age on an average.
In order to measure the body fat in participants, the scientists used a number of parameters such as waist-to-hip ratio, body mass index (BMI), and the overall fat.
The BMI was calculated by dividing the weight of the person by the square of height. For waist-to-hip ratio, the circumference of the waist was divided with the hip circumference. A higher ratio represented a bigger stomach in reference to the hips.
Experts say that people with BMI over 30 are obese. Central obesity, also known as obesity around the abdomen, is slightly different. For this type of obesity, a male with a waits-to-hip ratio of more than 0.9 and a female with above 0.85 are said to have central obesity.
The team measured the size of the brain with the help of MRI scans and investigated the volume of grey and white matter. Moreover, the scientists also checked some other factors that may affect the volume of the brain such as age, level of physical activity, smoking habit, and high blood pressure.
Changes in Gray Matter
The results of the study indicated different links between the body fat and the size of the brain. People having a higher waist-to-hip ratio, as well as BMI, were found to have the lowest brain volume. Those who only had a high BMI were having a slightly reduced brain volume as compared to completely normal people.
While the researches recorded notable differences in the volume of white matter, they were unable to find a link between obesity and a decrease in the sizes of various brain regions that control reward and motivation.
The Cause and Effects
After careful investigations and evaluation, the lead scientists along with the team have regarded obesity, especially the one surrounding the abdomen has a strong association with shrinkage of the brain.
However, the scientists were unable to determine whether obesity can cause a change in the volume of the brain or if any abnormalities occurring in the brain cause obesity.
The researchers of the study have admitted that their study included only a limited number of people and most of them were healthier as compared to the people who did not participate.
So it is not sure if these results can be applied to the general population and more extensive research is required.