Here’s a different way of looking at a challenging problem, and one that fits with what naturopathic doctors frequently see in practice.
In her new book, This is Depression, Dr. Diane McIntosh MD presents the idea that depression could be caused by an imbalance in the immune system.
There are cells in the brain called glial cells, which act as the brain’s caretakers. They supply neurons with nutrients, clean up any waste, and fight infection in the brain. They do a lot to keep the brain ticking along and doing its job.
Now, enter cortisol.
Cortisol is the hormone we produce when we experience high levels of stress. Whether that’s physical stress (like running a marathon), or mental stress (like studying for finals), or emotional stress (like dealing with a sick parent), cortisol is the hormone that we use to weather such storms.
Too much cortisol, however, causes those caretaker glial cells to stop working properly. Instead, they start spitting out proteins called pro-inflammatory cytokines, which are the signallers of the immune system; they tell your immune system to make inflammation. Those cytokines damage the glial cells, which causes them to release more cytokines, causing an inflammatory cascade. That inflammation in the brain results, in turn, in the neurotransmitters not working properly.
The end result? People feel brain fog, tired and low. They feel depressed.
With this explanation in mind, the research linking changes in diet and lifestyle to improving depression makes even more sense. Inflammation is your immune system doing its work, but sometimes that work has side effects. Lifestyle changes reduce that inflammation, and the result can be an anti-depressive effect.
In fact, as research shows, the outcome of lifestyle interventions can be better than a pharmaceutical anti-depressant. For example:
- Get teens off of a Standard North American Diet (that is highly inflammatory) and they get better.
- Exercise helps you rebalance high cortisol levels (thereby decreasing the inflammatory effect on glial cells).
- Exercise outside in nature and cortisol goes down even more.
- Fish oils (which are anti-inflammatory) help with depression.
Dr. McIntosh’s premise is still just a theory, but it’s one of those theories that we like, because there’s no real downside to the intervention. Healthy lifestyle changes are only going to make your life better–the side effects of reducing inflammation are all positive.
As the article in the Globe and Mail says:
Depression isn’t the only illness found to be caused by inflammation. Heart disease, HIV, lupus, arthritis, diabetes, obesity, chronic pain and several forms of cancer have also been called inflammatory disorders.
It makes a compelling case to take your fish oils, move your body outside, and eat well!