The greater the number of inches in the waist, follows a worrying list of health problems. Now new research provides strong evidence linking extra body mass, especially fat around the belly, to a worrying decrease in brain volume.
How this extra fat affects our brain function is unclear, but with previous research linking obesity to neurological conditions, it doesn’t seem very positive.
Starting from the BMI
BMI is determined by dividing a person’s weight by the square of their height. People with a BMI greater than 30.0 are considered obese. The waist-to-hip ratio is determined by dividing the waist circumference by the hip circumference. People with larger bellies compared to their hips have higher proportions. Men over 0.90 and women over 0.85 are considered centrally obese.
“Existing research has linked brain shrinkage to memory impairment and an increased risk of dementia, but research on whether extra body fat is protective or detrimental to brain size has been inconclusive,” explains Mark Hamer of Loughborough University. in Leicestershire (England) and leader of the work. ” Our research looked at a large group of people and found that obesity, specifically in the belly, could be related to brain shrinkage .”
The study evaluated 9,652 people with an average age of 55 years. Of that group, 19% were determined to be obese. The researchers measured BMI, waist-to-hip ratio, and overall body fat, and surveyed the participants about their health. The researchers then used magnetic resonance imaging to determine the brain volumes of white and gray matter in different regions of the brain.
Gray matter contains most of the nerve cells in the brain and includes regions of the brain involved in self-control, muscle control, and sensory perception. White matter contains bundles of nerve fibers that connect various regions of the brain.
After adjusting for other factors that can affect brain volume, such as age, physical activity, smoking, and high blood pressure, the researchers found that although a high BMI was only related to slightly lower brain volumes, those with a high BMI and a large waist, had lower gray matter brain volumes than participants who did not have a high waist-to-hip ratio.
Specifically, the researchers found that 1,291 people who had a high BMI and a high waist-to-hip ratio had the lowest average gray matter brain volume (786 cubic centimeters), compared to 3,025 healthy-weight people who had average brain volume. of gray matter of gray matter of 798 cubic centimeters. 514 people with a high BMI but without a high waist-to-hip ratio had an average gray matter brain volume of 793 cubic centimeters. They found no significant differences in brain volume of white matter.
“While our study found that obesity, especially in the environment, was associated with lower brain volumes of gray matter, it is unclear whether abnormalities in brain structure lead to obesity or whether obesity leads to these changes in the brain, “Hamer said. “We also found links between obesity and shrinkage in specific regions of the brain. This will require more research, but it may be possible that one day regularly measuring BMI and waist-to-hip ratio will help determine brain health.”
A limitation of the study was that only 5% of those invited to participate in the study participated, and those who participated tended to be healthier than those who did not, so the results may not reflect the population as a whole.
Reference: Neurology
