Fifteen million people suffer strokes worldwide each year. Obesity plays a role in many of those. Brain plasticity, or the brain’s ability to create new neural pathways, is critical to stroke recovery. But does obesity both increase stroke risk and impair the brain’s ability to recover from stroke?
In a first-of-it’s-kind study, researchers at the University of South Australia and Deakin Univeristy have found the answer to this question. Their findings show that obese people are less able to re-wire their brains. This inability to find new neural pathways represents a considerable problem for those recovering from a stroke or a brain injury.
The study findings were published in Brain Sciences, and indicate that obese people may also be less able to learn new tasks and may even have memory issues related to a lack of brain plasticity.
The scientists worked with a group of fifteen obese people between the ages of 18 and 60, along with a control group of 15 people of healthy weight. They tested each participant using transcranial magnetic stimulation.
They applied repeated pulses of electrical stimulation to the brains of each person and measured the strength of the responses. In the obese group, brain responses were minimal. This suggested impaired plasticity. The healthy-weight group showed significant neural activity when tested, indicating normal brain plasticity.
University of South Australia researcher Dr. Brenton Hordacre believes their findings are the first physiological evidence of the connection between human obesity and impaired or reduced brain plasticity.
While the use of body mass index, or BMI, as an accurate test for obesity is often disputed, for research purposes it is used as a means of creating a uniform baseline measure. It is a calculation based on height and weight used to determine body fat. A measure between 25 and 29.9 is considered overweight, while a measure of 30 or more is considered obese.
“Obesity is already associated with a raft of adverse health effects, including a higher risk of cardiovascular disease, metabolic disorders and dementia,” Dr Hordacre says.
“For the first time, we found that obesity was associated with impaired brain function, adding further support for the need to address the obesity epidemic.
“A growing number of people are obese — 650 million according to the World Health Organization — which not only has health consequences but is a serious financial burden for global health systems,” he says.
“These new findings suggest that losing weight is particularly important for healthy brain ageing or for recovery in people who suffer strokes or brain injuries, where learning is fundamental for recovery.”
Stroke is a leading cause of death in virtually every industrialized nation. The lasting effects of the damage from stroke include reduced cognition, memory impairment and speech disorders. Adequate levels of brain plasticity are needed to overcome these effects.
More research is needed, to be sure. But this study certainly provides a good start in making the connection between obesity and impaired brain plasticity. It would seem that it’s just one more reason to stop ignoring the obesity crisis around the world.
Keep the faith and keep after it!
Journal Reference – Sophia X. Sui, Michael C. Ridding, Brenton Hordacre. Obesity is Associated with Reduced Plasticity of the Human Motor Cortex. Brain Sciences, 2020; 10 (9): 579 DOI: 10.3390/brainsci10090579