Serotonin (5-HT), although popularly referred to as the ‘happiness hormone’, is a biogenic amine produced mainly in the intestines in response to stress and irritation. The association between digestive distress and mood fluctuations is well known.
Increased serotonin levels have been linked to the onset and development of many diseases from MS, Alzheimer’s and Parkinsons, to Autism, Irritable Bowel Syndrome, Crohn’s disease, cancer and more.
Contrary to popular belief, much research has shown serotonin to be part of an inhibitory system of harm avoidance. The relationship between increased serotonin and depression has been compared to serotonin’s biological role in hibernation.
Although humans technically don’t hibernate, serotonin suppresses metabolism thereby interfering with glucose utilization – reducing brain function and promoting the oxidation of fat for fuel – mimicking many aspects of torpor.
Serotonin production is promoted by the polyunsaturated fats as well as by many foods or substances that irritate or interfere with digestion, encouraging bacterial growth. Bacterial toxins are known promoters of anxiety and aggressive behaviour.
Intestinal serotonin secretion increases in direct response to rising levels of bacterial endotoxin release, and studies have increasingly confirmed the inflammation and disease promoting effects of rising levels of endotoxin which pass into the blood stream.
The more serotonin interferes with metabolism – slowing digestion and intestinal barrier function – the harder it is for the liver to carry out its detoxification function, allowing rising levels of the stress substances (including estrogen, serotonin, endotoxin and the polyunsaturated free fatty acids) to interact with each other throughout the main system, leading to what can become a vicious circle of degeneration.
Apart from the seed and fish oils, fibrous under cooked vegetable matter, grains, beans, nuts, seeds and legumes and various starches, can all also promote serotonin secretion.
Foods often used to improve metabolism and reduce serotonin include dairy products as well as many sweet ripe fruits and simple sugars like honey or sucrose.
A variety of anti-serotonergic drugs have been used to successfully treat depression and numerous related diseases of inflammation.
See more here.