- When the brain loses its sensitivity to insulin, increased hunger and disrupted metabolism often follow.
- Reduced insulin sensitivity in the brain can lead to weight gain, which increases the risk of type 2 diabetes.
- A new study finds that an 8-week exercise program consisting of 1 hour of exercise 3 times a week can restore the brain’s insulin sensitivity in individuals with obesity.
The link between brain insulin insensitivity and diabetes is well established, but the exact nature of that connection is still being studied.
New research from researchers at the German Center for Diabetes Research, University Hospital Tübingen, and Helmholtz Munich in Munich, Germany, explores the effect of exercise on the brain’s insulin sensitivity.
The study found that healthy levels of brain insulin sensitivity were restored in participants after an 8-week exercise program.
The findings were recently published in JCI perspective.
“This study reinforces the fact that physical activity is necessary to restore the metabolic pathways of the mind and body in patients with obesity, prediabetes, diabetes and metabolic diseases in general.” Dr. Ana Maria Kauselendocrinologist and co-founder of Anzara Health, who was not involved in the study, said Today’s medical news.
For the study, 21 healthy overweight and obese participants were enrolled in an 8-week supervised aerobic exercise program.
The cohort included 14 men and 7 women with a body mass index (BMI) ranging from 27.5 to 45.5 kg/m2. The participants led sedentary lifestyles and were considered to be at risk of developing type 2 diabetes.
Three times a week, the participants performed 1-hour resistance training sessions. Each session included a combination of cycling and walking to get people up to 80% of their maximal oxygen uptake, or VO2 max.
Using fMRI after administering an insulin nasal spray to each individual, the researchers assessed their brain sensitivity to insulin at the start of the study and after 8 weeks.
The exercise program increased insulin action in the striatum of the brain and strengthened Functional connections in the hippocampus at levels in people without overweight or obesity.
The researchers found that improving insulin sensitivity in the brain had positive effects on the participants’ metabolism and reduced their feelings of hunger. The participants also reduced the amount of visceral fat, which further benefited their health.
Ryan GlattCPT, NBC-HWC, a personal trainer and brain health coach at the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA, who was not involved in the study, noted the following for MNT:
“This was an interesting study; however, the sample size was very small (21 people), with twice as many women as men, making the study underpowered, especially in the absence of a control group.”
Insulin is a hormone produced by the pancreas that helps the body regulate blood sugar levels.
In type 1 diabetes, for example, the immune system attacks the cells that produce insulin in the pancreas. In type 2 diabetesthe body becomes resistant to the insulin it produces.
Although insulin resistance is an element of prediabetes and type 2 diabetes, insulin resistance in the brain is not the same thing.
“Insulin insensitivity of the brain can be correlated with diabetes and obesity, but it has more to do with brain metabolism and its efficiency,” Glatt explained.
Dr Ahmet Erginsaid a SugarMD endocrinologist MNT they agreed, noting that insulin affects brain function.
“Studies have shown that insulin plays a role in neurotransmission, meaning it can influence our mood, behavior and cognition,” said Dr. Ergin. “One theory is that insulin insensitivity in the brain directly causes diabetes by preventing the body from properly processing glucose.”
“Another theory suggests that weight gain is the main driver of diabetes and that insulin insensitivity of the brain is indirectly related to the disease. This second theory is supported by research showing that people who are overweight are more likely to develop diabetes, even if they don’t have any other risk factors. Ultimately, more research is needed to determine the exact relationship between insulin resistance in the brain and diabetes. However, it is clear that the two conditions are strongly linked and that managing one can help prevent the other.”
– Dr. Ahmet Ergin, endocrinologist
Dr. Kausel described insulin resistance as a “vicious cycle,” noting that the process begins in the liver before it begins to affect different organs, such as the brain.
“When we have insulin resistance in the brain, the important connection between the brain and the gut for hunger [or] satiety signals and metabolism are impaired, making the problem even worse,” said Dr. Kausel.
Symptoms of cerebral insulin resistance to watch out for include:
- chronic fatigue
- brain fog
- long-term memory problems
- constant hunger
Signs of insulin resistance in the brain may go unnoticed as these symptoms are also shared by other chronic health conditions.
“Symptoms of insulin resistance in the brain include feeling tired after eating, cravings for sugary foods, and difficulty concentrating,” said Dr. Ergin.
“In severe cases, insulin resistance in the brain can lead to weight gain, type 2 diabetes, and other health problems. Because the symptoms of insulin resistance in the brain are similar to those of other conditions, it can be difficult to diagnose,” he added.
For people who have been diagnosed with insulin resistance in the brain or those who are worried they might have it based on their symptoms, exercise is linked to better overall health.
Making a change away from a sedentary lifestyle is unlikely to cause any harm, but it’s a good idea to talk to your doctor first.
“I always tell my patients to start where they can, that’s the first and hardest step,” said Dr. Kausel.
“Make sure they enjoy the activity so they can stick with it long-term, and each week add 5 minutes until they can do it for at least 45 minutes. No matter the activity, the point is to move.”
Dr. Ergin added that exercising to restore insulin sensitivity can seem like a daunting task, so it’s important to start slow and set realistic goals.
“Every journey begins with a single step,” said Dr. Ergin. “A person can start by walking for 20 minutes each day and gradually increase the length and intensity of their workouts over time.”
Dr. Ergin emphasized muscle-strengthening exercises, such as lifting weights or using resistance bands, which can help improve insulin sensitivity.
To stay motivated and consistent with your exercise routine, Dr. Ergin recommends building a support system of friends or family members who are also working to improve their health.
“By following these simple tips, anyone can start working toward a healthier lifestyle,” he said.