- When the brain loses its sensitivity to insulin, increased hunger and disrupted metabolism often ensue.
- Reduced brain sensitivity to insulin can lead to weight gain, increasing the risk of type 2 diabetes.
- 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 obese people.
The link between cerebral insulin insensitivity and diabetes is well established, but the exact nature of this link is still under investigation.
New research from researchers at the German Diabetes Research Center, University Hospital Tübingen and Helmholtz Munich in Munich, Germany, explores the effect of exercise on brain insulin sensitivity.
The study found that healthy levels of brain insulin sensitivity were restored in participants after an 8-week exercise program.
The results were recently published in JCI Overview.
“This study reinforces that physical activity is necessary to restore mind-body metabolic pathways in patients with obesity, prediabetes, diabetes, and metabolic diseases in general,” Dr. Ana Maria Kauselan endocrinologist and co-founder of Anzara Health, not involved in the study, said Medical News Today.
For the study, 21 healthy participants with overweight and obesity 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 deemed to be at risk of developing type 2 diabetes.
Three times a week, the participants completed hour-long endurance training sessions. Each session included a combination of cycling and walking to get individuals up to 80% of their maximal oxygen supply, or VO2 max.
Using a functional MRI after administering an insulin nasal spray to each individual, the researchers assessed their brain’s sensitivity to insulin at the start of the study and after 8 weeks.
The exercise program increased insulin action in the brain’s striatum and enhanced functional connections in the hippocampus at levels of people without overweight or obesity.
Researchers found that improved insulin sensitivity in the brain had positive effects on participants’ metabolism and reduced their feelings of hunger. Participants also decreased their amount of visceral fat, which further improved their health.
Ryan GlattCPT, NBC-HWC, personal trainer and brain health coach for the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, Calif., not involved in the study, noted the following for DTM:
“It 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 control group.”
Insulin is a hormone produced by the pancreas that helps the body regulate blood sugar.
In type 1 diabetes, for example, the immune system attacks cells that produce insulin in the pancreas. In Type 2 diabetesthe body becomes resistant to the insulin it produces.
Although insulin resistance is a component of prediabetes and type 2 diabetes, brain insulin resistance is not quite the same thing.
“Brain insulin insensitivity may be correlated with diabetes and obesity, but it’s more related to brain metabolism and its efficiency,” Glatt explained.
Dr Ahmet Erginsaid an endocrinologist at SugarMD DTM agree, 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,” Dr. Ergin said. “One theory is that brain insensitivity to insulin directly causes diabetes by preventing the body from processing glucose properly.”
“Another theory suggests that weight gain is the main driver of diabetes and that brain insulin insensitivity is indirectly linked to the disease. This second theory is supported by research showing that overweight people are more likely developing diabetes, even if they have no other risk factors. Ultimately, more research is needed to determine the exact relationship between brain insulin resistance and diabetes. However, it is clear that the two conditions are strongly linked and 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 brain insulin resistance, the important link between the brain and the gut for hunger [or] satiety signals and metabolism are impaired, further compounding the problem,” Dr. Kausel said.
Symptoms of cerebral insulin resistance to watch out for include:
- chronic fatigue
- brain fog
- long-term memory problems
- constant hunger
Signs of brain insulin resistance may go unnoticed since 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,” Dr. Ergin said.
“In severe cases, brain insulin resistance can lead to weight gain, type 2 diabetes, and other health issues. Because the symptoms of cerebral insulin resistance are similar to those of other conditions, it can be difficult to diagnose,” he added.
For people with diagnosed brain insulin resistance or those who fear they may have it due to their symptoms, exercise is linked to improved overall health.
Moving away from a sedentary lifestyle is unlikely to cause harm, but it’s a good idea to speak with your doctor first.
“I always tell my patients to start as best they can — that’s the first and hardest step,” Dr. Kausel said.
“Make sure they enjoy the activity so they can sustain it long term, and every week add 5 minutes to it until they can do it for at least 45 minutes. activity is all about moving.
Dr. Ergin added that exercising to restore insulin sensitivity can seem like a daunting task, which is why it’s important to start slowly and set realistic goals.
“Every journey begins with a single step,” Dr. Ergin said. “A person can start with walking for 20 minutes every day and gradually increase the duration and intensity of their workouts over time.”
Dr. Ergin emphasized exercises that strengthen muscles, such as lifting weights or using resistance bands, which can help improve insulin sensitivity.
To stay motivated and consistent with your workout routine, Dr. Ergin recommends building a support system with friends or family members who are also working to improve your health.
“By following these simple tips, anyone can start working towards a healthier lifestyle,” he said.