The holidays are a time of joy and happiness. But sometimes this time of year can leave you feeling a bit low. You want to do something about it, but what? According to the Centers for Disease Control (CDC) more than 1 in 9 Americans over age 12 take an antidepressant and 60% will be on it for 2 years or more.
Several studies have shown that moderate exercise can be as effective as taking an antidepressant for mild to moderate depression. And we’re not talking about running a marathon. Just walking 35 minutes 6 days per week lowered mild to moderate depression by 47%. But how? Walking doesn’t greatly increase endorphins.
A new study in the New England Journal (Dec 11, 2014) believes they have the answer: kynurenine.
Turns out that in the absence of exercise, stress greatly increases production of this substance in the liver, spleen and monocytes (at type of white blood cell). Kynurenine finds its way into the bloodstream and brain and causes inflammation, free radicals and influences brain metabolism and behavior that leads to – you guessed it – depression.
The antidote is exercise. When you are stressed and you exercise, your muscles produce enzymes called KATs or kynurenine aminotransferases that metabolize the kynurenine and the byproduct (kynurenic acid) can’t get from the blood stream into the brain. That creates resilience to stress.
This is particularly helpful in menopause and with type 2 diabetes when kynurenine levels are typically higher.
So enjoy the holiday season. And if you feel a little down, before taking a pill, try taking a walk.