The idea that exercise can help reduce stress and mood is widely known. The most common known reason is the fact that endorphins are released during exercise which elevates mood. New research done by the Karolinska Institutet in Sweden has found that exercise can help protect the brain against stress-induced depression through an avenue not previously explored. Exercise is used clinically as part of treatment protocol for depression and this research helps provide reasoning as to why it is so important.
With exercise, a protein called PGC-1a1 increases in skeletal muscle causing an increase in enzymes known as KATs, (Karolinska Instiutet 2014). These enzymes break down a substance, kynurenine, that is in high levels of people with mental illness and is also formed during stress, (Karolinska Instiutet 2014). These harmful substances are no longer able to cross the blood brain barrier, creating a protective effect against depression. The research also showed that high levels of PGC-1a1 in mice allowed for a preventative measure against stress, (Karolinska Instiutet 2014). When mice that had high levels of PGC-1a1 were injected with high levels of the stress related substance, kynurenine, they did not display any depressive behavior, (Karolinska Instiutet 2014). This is in contrast to mice who did not have high levels of PGC-1a1 who did display depressive behavior when given an injection of kynurenine, (Karolinska Instiutet 2014). This is important in warding off depression during times of high stress.
Medications could be made which mimic the effects of exercise on the skeletal muscle, decreasing stress byproducts that are known to damage the brain, (Aguedelo et al. 2014). Most pharmaceutical treatments for depression involve targeting chemicals in the brain where as this new research could facilitate new advancements in medications that target the skeletal muscle. Creating a medication with an alternative pathway in treating depression could open the door to protecting the brain from depression.
Furthermore, it is also important to recognize that this research has provided an additional reason as to why exercise is important as a daily habit and as clinical treatment. There are many people who have bad side effects due to medications for treating depression. While depression treatment protocols need to be advised by a medical professional, the new information showing the mechanism behind exercise and mental health illnesses provide further evidence that exercise should be included in treatment.
Citations:
Karolinska Institutet. 2014 September 25. How physical exercise protects the brain from stress-induced depression. Science Daily. [Internet]. [cited on 2014 September 28]. Available from:
Agudelo LZ, et al. 2014 September 25. Skeletal Muscle PGC-1α1 Modulates Kynurenine Metabolism and Mediates Resilience to Stress-Induced Depression. PubMed. [Internet]. [cited 2014 September 28]. Available from: http://www.ncbi.nlm.nih.gov/pubmed/?term=Skeletal+Muscle+PGC-1%CE%B11+Modulates+Kynurenine+Metabolism+and+Mediates+Resilience+to+Stress-Induced+Depression
This study is very interesting and I think that another reason to get people working out is always a good thing! Did the study mention if the people who were studies with mental illness had been exercising prior to there diagnosis? How often do you think would be enough exercise for a person to have an increase in PGC-1a1? Finally if a person works out and increases the KAT enzyme how long will the KAT enzyme stay? I also think that along with endorphins and this new mechanism found from exercise I also believe that exercise leads to an increase in self-esteem and provides a sense of belonging which could also decrease depression.
ReplyDeleteI did like that this study shows the effects of the muscle cell enzymes and their effect on depression. What I am wondering though is how this exercise is effecting the already known chemical, such as dopamine and serotonin? As in, does exercise increase the amount of serotonin in the body? If that is the case in humans than is it this effect masking the other enzymes. According to this study by Science Direct, exercise significantly increases the amount of serotonin in the hypothalamus and the brain stem. One cannot deny the effect of PGC-1a1 because of the effect it had on murine models. It it just hard to tell if this is the majority of the anit-depressant effect is coming from these enzymes or chemical signals that were previously known. Perhaps if the real effect of exercise in the increase of serotonin, which is what many anti-depressants prevent the reuptake of. Since you did mention that many patients have negative responses to SSRIs, perhaps exercise is the best medication for them.
ReplyDeletehttp://www.sciencedirect.com/science/article/pii/003193849290465E