In addition to all the stuff Sisson discusses about pattern recognition receptors (PRR), plasma and leukocytes, and bradykinin – none of which I fully understand – there is the pragmatic concept that I can follow: inflammation causes pain and swelling, which partly immobilizes and discourages our use of the area, giving it the rest it needs to heal.
The down side comes when inflammation becomes chronic and systemic rather than acute, short-lived and isolated.
Dr. Andrew Weil, in an article at huffingtonpost.com, talks about “the cytokine hypothesis of depression” and explains that cytokines are “proteins made by immune cells that govern responses to foreign antigens and germs,” and that they are “the principal chemical mediators of the inflammation response.” Cytokines can be pro-inflammatory or anti-inflammatory. The release of pro-inflammatory cytokines can affect mood.
In an article on psychologytoday.com, Dr. James M Greenblatt discusses three studies that have helped in understanding the connection between inflammation and depression. In one study, patients with major depressive disorder (MDD) were found to have significantly higher levels of a pro-inflammatory cytokine and lower levels of anti-inflammatory cytokines than their non-depressed counterparts. Another study showed that the antidepressant Zoloft decreased pro-inflammatory cytokines and increased anti-inflammatory cytokines. In a third study, depressed patients who were classified as "non-responders” had their standard antidepressant treatment supplemented with aspirin, an anti-inflammatory. Greenblatt reports that “More than 50% of these patients responded to this combination treatment. At the end of the study more than 80% of the group responsive to the anti-inflammatory went into remission.” Do we see a trend there? Anti-inflammatory cytokines, good. Pro-inflammatory cytokines, not so good.
Greenblatt tells us that “One mechanism as to how an unregulated immune system may contribute to depression is quite well understood. Cytokines activate an enzyme… which degrades [the neurotransmitter] serotonin resulting in low levels of [serotonin].” Serotonin is thought to be a contributor to feelings of well-being and happiness. The enzyme activated by the cytokines also degrades tryptophan, the precursor to serotonin. These lowered levels of serotonin “are likely the contributing factor to the development of depressive symptoms. The inflammatory process' contribution to the constant destruction of serotonin decreases the chances of recovery.”
So what do we do to help contain unnecessary inflammation? Dr. Weil points to a number of proactive measures we can take. Following an anti-inflammatory diet is first and foremost. Weil has created an anti-inflammatory food pyramid to help encapsulate the eating regimen that he recommends. I, of course, am quicker to look to the Paleo Diet, which has also been shown to reduce inflammation. In addition to eating more healthily, exercise and stress-reduction are advised for reducing the bad effects of inflammation.
There is a lot of interesting information online about inflammation as it relates to depression, and if this interests you at all, I encourage further reading. It’s amazing how our bodies’ systems and functions are so interconnected.
To your health... mental and otherwise.