Research is constantly backing up what we know about the benefits of exercise.
We know, of course, that’s it’s good for our bodies — in terms of both health and body composition. We also know that exercise is a boon for our minds — benefiting our physical brains as well as our mental health.
It’s in this tradition, then, that new research is finding out more about the relationship between exercise and its benefits for both mind and body.
A new Swedish study has built on previous research to show exercise benefits both body and mind through the same mechanism.
In 2014, researchers from the Karolinska Institutet demonstrated that exercising your muscles convert kynurenine, a marker of stress that is high in people with depression and other mental illnesses, into another substance, kynurenic acid.
In the new study, the same researchers further looked at kynurenic acid and its effects on body composition.
“We’ve linked the two parts of the expression ‘sound mind, sound body’,” says Dr. Jorge Ruas, one of the study authors. “Our research adds to the understanding of why exercise training benefits the body and in the long run can lead to the development of new treatments for obesity or diabetes.”
Researchers put mice on a high-fat diet, which made them overweight and raised their blood sugar. Then they administered kynurenic acid to the mice one per day and measured the results.
The results showed that after taking the kynurenic acid, the mice stopped putting on weight and had better glucose tolerance. This was without changing the mice’s diet at all.
Researchers believe the reason for this is that the kynurenic acid activated a cell receptor called GPR35, which is in fat cells and immune cells.
“We’ve shown that kynurenic acid prevents weight gain despite excessive energy intake,” says Dr Jorge Ruas. “Our next step is to identify the complex chain of interacting molecules that’s affected by diet and training.”
The bottom line? Exercise is good for both your body and your mind.
1. Leandro Z. Agudelo et al. (2014.) ‘Skeletal Muscle PGC-1α1 Modulates Kynurenine Metabolism and Mediates Resilience to Stress-Induced Depression.’ Cell. Volume 159, Issue 1, p33–45, 25 September 2014. DOI: https://doi.org/10.1016/j.cell.2014.07.051
2. Leandro Z. Agudelo et al. (2018.) ‘Kynurenic Acid and Gpr35 Regulate Adipose Tissue Energy Homeostasis and Inflammation.’ Volume 27, Issue 2, p378–392.e5, 6 February 2018. DOI: https://doi.org/10.1016/j.cmet.2018.01.004