If you have been following my blog for any length of time, you know that I appreciate the sacrifice that mice and rats make for science. In this case, researchers created heart attacks in rats and monitored them for depression with or without estrogen. They found that female rats who had their ovaries removed experienced more “rat depression” after this heart attack than female rats who were given an estrogen pellet after their ovaries were removed. Beyond just noting depressive behavior in these rats, they also measured inflammatory markers in the rats’ brains. Given that researchers on the whole are finding more and more links between brain inflammation and mood disorders, there is definitely a strong link in this case.
Human observational studies reveal an increase in depression rates after men or women have a heart attack. This increased depression appears linked with increased inflammation according to other studies and can be decreased with anti-inflammatory therapies. The inflammation serves an early purpose to help remodel the heart and recover from the injury, but if it continues too long, both the heart and the brain can suffer long term consequences.
There is far too much information to summarize this article completely, but here are a few tidbits to whet your appetite. Through an experimental process, estrogen appears to be the primary variable leading to lower post-heart attack depression rates. Inflammatory markers in the peripheral blood and brain correlate with these symptoms and estrogen levels. Lower estrogen rats showed higher symptoms and higher inflammation markers. The inflammation markers included interleukins (IL), Tumor Necrosis Factor (TNF), quinolinic acid, and glutamate activity (excites neurons, sometimes too much and causes damage). The important chemical BDNF (Brain Derived Neurotrophic Factor) which stimulate nerve cell growth is lowered. Quinolinic acid was elevated in the inflamed rat brains, a marker that the IDO enzyme was shunting tryptophan away from serotonin production, into the inflammatory pathway.
Besides reminding me how our brains, immune system, and hearts are so interconnected, it encourages me to hear things like BDNF and quinolinic acid. On a regular basis in our office, we are working to improve brain health through stimulating BDNF and are measuring/treating quinolinic acid on our organic acid testing. I love practicing functional medicine where we take breakthroughs from the journals into the exam rooms. It’s a great way to help our patients find their healthier, more abundant life again.
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.