Exercise Protects Against Depression

According to a new study regular exercise may help to safeguard the mind against depression through its effects on muscles. Mental health experts have long been aware that exercise somehow makes people and animals emotionally more positive, but precisely how this happens has been a mystery. Researchers at the Karolinska Institute in Stockholm knew from earlier research that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme called PGC-1alpha1 (PGC). In studies using mice they found that this enzyme protects the brain from a substance called kynurenine which is related to stress. 
Kynurenine is able to pass the blood-brain barrier, and once inside the brain it creates inflammation that is thought to cause depression. Exercise elevates the body’s level of PGC, and this breaks down the kynurenine so that it cannot pass the blood-brain barrier. Thus the brain is protected from the inflammation and depression that is caused by stress. The study’s simple conclusion was that, “Exercise reduces the risk of depression.” So if work and other pressures are getting you down, it may be a good idea to go for a jog... just to keep your kynurenine in check.