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A new study suggests that motivation may be improved through nutritional interventions. Studio Marmellata/Stocksy
  • Motivation has to do with people’s drive to complete tasks and is influenced by internal and external factors.
  • Researchers are still working to understand what factors in the brain influence motivation.
  • A​ recent study found that levels of the antioxidant GSH, which can be increased through diet and lifestyle changes, may influence motivation levels.

People often want to get more done in a day, but sometimes it’s hard to feel motivated to complete tasks. Several factors influence motivation, but there’s a lot about the physiology behind motivation that experts don’t completely understand.

A​ recent study published in eLife found that levels of the antioxidant glutathione in a specific part of the brain likely play a key role in motivation levels.

One can increase their glutathione levels through dietary sources, for example, by eating sulfur-rich foods such as meat, eggs, and grains, and consuming more dairy and whey protein.

The research was conducted by Ecole Polytechnique Federale de Lausanne (EPFL) and Nestle.

Motivation involves people’s energy and persistence to achieve tasks and goals. Motivation helps people succeed in the workplace and other spheres of life, allowing them to meet their needs.

Multiple factors influence motivation, including people’s environment, history, and physical health.

Experts have come up with multiple theories that attempt to explain what drives motivation. However, there is a lot about the underlying mechanisms of motivation that experts still don’t fully understand.

This study’s researchers looked at how oxidative stress and antioxidant levels may influence motivation. Oxidative stress has to do with the harmful molecules (free radicals) that the body produces as a byproduct of metabolism. Antioxidants help to neutralize these free radicals.

One of the most common antioxidants in the brain is glutathione (GSH).

Dr. Erika Gray, chief medical officer, and co-founder of ToolBox Genomics, who was not involved in the study, explained to Medical News Today:

“One way your body clears oxidative stress is through antioxidants, and glutathione is one of the primary antioxidants. Glutathione is your body’s internal antioxidant, and it is made in the liver from the amino acids cysteine, glutamate, and glycine.”

Glutathione, unlike most antioxidants that are plant-derived, can be naturally produced by the liver. However, levels of this antioxidant are also known to decrease naturally with age. Hence, it may be important to get more glutathione through food.

Researchers looked at how levels of this antioxidant in a specific brain area, the nucleus accumbens, influenced motivation. First, researchers used proton magnetic resonance spectroscopy to examine GSH levels in rat and human brains.

They found that higher levels of GSH were associated with more consistent and better performance in tasks that required effort.

T​hey were then able to look more into causality through experiments with the rats. They found that decreasing GSH levels reduced rats’ efforts to complete effort-based tasks.

When rats were given a precursor to GSH to increase brain levels of GSH, their performance improved.

Study author, Professor Carmen Sandi, director of the Laboratory of Behavioral Genetics, Brain Mind Institute at EPFL in Switzerland, explained to MNT:

“We found that the actual levels of the most important antioxidant in the nucleus accumbens—a part of the ventral striatum and a hub of the brain motivational system—determine the capacity to keep exerting effort over time to obtain rewards…our study suggests that the antioxidant system in the brain hub for motivation is critical to determine our capacity to keep going with tasks that require effort but provide advantages for us/rewards.”

How diet can impact the brain, antioxidant levels

“Nutrition, including compounds that help the antioxidant systems, is a good way to improve the fitness of brain circuits regulating persistence in our motivated behavior. Other life experiences that would be good are doing regular exercise while avoiding high stress levels or high-fat meals and obesity.”
— Prof. Carmen Sandi

The study did have some limitations that the reader needs to consider. First, part of the research involved rats, which can only provide limited information. Second, in the research that did involve humans, researchers only included male subjects in the analysis, which only provides data about some members of the population.

I​n addition, the study only included a small sample size, further indicating the need for more research.

Prof. Sandi noted a few areas for continued research.

“We need to perform a larger scale study, stratifying individuals for differences in the content of glutathione in the nucleus accumbens and studying how nutritional—or pharmacological—interventions can help improve their capacity to keep going with tasks and effort exertion,” she said.

Prof. Sandi said future research would have to address the following questions:

“Would all individuals benefit equally, or [would the results] be particularly positive for those displaying low levels of the antioxidant glutathione? And what scheme of administration would be more efficient?”

Overall, the study opens multiple possibilities for future research and emphasizes a potential underlying element to motivation levels. Because glutathione is in certain foods, diet may play a key role in increasing glutathione levels in the body.

“Eating foods naturally high in glutathione such as asparagus, raw avocado, potatoes, [and] raw spinach,” may help increase glutathione levels. People can work with their doctors and nutrition specialists to create a dietary plan that fits their needs, including to increase antioxidant levels.”
— Dr. Erika Gray