Can Obesity Shrink Your Brain?

Summary:

According to new research, obesity could shrink your brain and potentially lower your cognitive skills as you get older.
The brain can be directly affected by the accumulation of significant body fat over time.
Being overweight or obese can increase the risk of dementia and cause the changes to gradually take place in the brain many years before symptoms appear.

Study of Obesity and Brain Shrinkage

Carrying excess weight is bad for your heart, increases your risk of chronic diseases like diabetes, and can shorten your lifespan. But have you ever thought that obesity could shrink your brain? Probably not, but according to new research, it can do just that – and potentially lower your cognitive skills as you get older.

The study, which was carried out at Leiden University Hospital in the Netherlands, found that obese people seem to shrink more in brain tissue than people of normal weight, and that the changes often occur in middle age. These results are based on a survey of more than 12,000 men and women living in the UK. All subjects were between 45 and 76 years old.

An MRI brain scan was performed on each participant to provide detailed information about the structure and volume of their gray and white matter. In addition, their body fat levels were assessed using bioelectrical impedance, a body composition analysis method that sends weak electrical currents through the body to determine an approximate percentage of body fat.

Both the male and female volunteers with larger body fat stores had microscopic structural differences in the white matter of their brains compared to their peers with less body fat. The white matter is full of fibers that connect different areas of the brain.

Influence of gender on studies

However, the differences also depended on gender. The men with higher body fat tended to have a lower overall volume of gray matter, and the most affected areas of the gray matter of the brain were the caudate nucleus, globus pallidus, hippocampus, nucleus accumbens, putamen, and thalamus . These regions are primarily either associated with body movement functions or are reward centers. Interestingly, in female subjects with a higher body fat percentage, only a connection with a reduction in volume in the globus pallidus area of the gray matter was established. The Globus Pallidus is responsible for regulating our voluntary movements.

The research was not designed to prove cause and effect, just to determine a connection. And there are certain limitations as the subjects' cognitive abilities were not assessed. Hence, we have no idea whether these changes in structure and volume necessarily affect memory or other mental faculties.

Obesity & Brain Damage

That being said, the research offers compelling evidence that the brain can be directly affected by the accumulation of significant body fat over time. Furthermore, this isn't the first time obesity has been linked to potentially harmful brain changes. A 2019 study at Loughborough University in England showed that middle-aged men and women with high waist-to-hip ratios had a lower volume of gray matter in the brain than people with thinner waists due to belly fat. To go a step further, research has been conducted into linking overweight or obesity to an increased risk of developing early Alzheimer's disease. Numerous studies have shown that gray matter shrinkage over time is linked to an increased risk of dementia.

Ultimately, the current research appears to be another piece of the puzzle that comes together as we figure out what contributes to dementia. It seems increasingly clear that being overweight or obese can increase the risk of dementia and that the changes take place gradually in the brain many years before symptoms appear.

So, if you are overweight, now is the time to make important lifestyle improvements to prevent irreversible cognitive decline in your later years, as well as a host of other health problems. Eating fewer calories, making more nutritious choices, devoting some time each day to exercise, and reducing stress can go a long way in keeping your weight within the normal range and staying healthy in the future.