Have you ever wondered why sometimes you choose to exercise, while other times you give in to a tasty snack?
Researchers at ETH Zurich have discovered what happens in our brain when we make this decision.
They identified a brain chemical called orexin and the neurons that produce it as key players in this process.
This discovery is important because many people do not get enough exercise.
According to the World Health Organization, 80% of adolescents and 27% of adults don’t exercise enough.
This lack of exercise contributes to rising obesity rates, not just among adults but also among children and teens.
Professor Denis Burdakov from ETH Zurich explained that their research aimed to understand what helps some people resist temptations and choose to exercise.
In their experiments with mice, the researchers found that orexin is crucial in this decision-making process.
Orexin is one of over a hundred messenger substances in the brain, but it was discovered only about 25 years ago, and scientists are still learning about its functions.
Dopamine, another brain messenger, is well-known for its role in motivation, but it doesn’t fully explain why we might choose exercise over eating. Both activities release dopamine, so something else must be influencing our choices.
To investigate this, the researchers set up an experiment where mice could choose between running on a wheel or enjoying a strawberry-flavored milkshake.
The mice had ten minutes to decide, and the researchers compared the behavior of normal mice with that of mice whose orexin systems were blocked, either with a drug or through genetic modification.
The results were clear. Mice with an intact orexin system spent twice as much time running on the wheel and half as much time at the milkshake bar compared to mice with blocked orexin systems.
However, when only one option was available (either the wheel or the milkshake), there was no difference in behavior between the two groups of mice. This suggests that orexin doesn’t control how much the mice move or eat but helps them decide between exercising and eating when both options are available.
Without orexin, the mice were more likely to choose the milkshake over exercising.
The researchers believe that orexin likely plays the same role in humans because our brains function similarly to those of mice.
To confirm their findings, they plan to study people with genetic conditions affecting their orexin systems, such as those with narcolepsy (a sleep disorder), or those taking drugs that block orexin.
Understanding how our brain decides between food and exercise could lead to better strategies for tackling obesity and related health issues. Future interventions might help people overcome barriers to exercise, making it easier for them to stay active and healthy.
For now, the research team at ETH Zurich will continue their work to understand how orexin neurons interact with the rest of the brain in making these important decisions.
If you care about brain health, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
