For as long as I remember, I’ve always hated winter, apart from when it’s cold and sunny; that I can somehow cope with. To this day, I’m convinced I should really be living in the tropics, or, at the very least, the Mediterranean. I love summer – I love the heat, the brightness of the light, the intensity… The only time that I really seem to embrace winter is when I go skiing. The strength of the sun at altitude energizes me; it always has done. There’s a reason for this of course. It’s all down to a little molecule called serotonin.
Serotonin is a fairly unassuming molecule when you first meet it. It’s also known as 5-hydroxytryptamine (5-HT), and is made in the brain and the intestines. It is formed from tryptophan, one of the essential amino acids. “Essential” here refers to the fact that you have to acquire tryptophan via your food, because the body cannot manufacture it.
Serotonin is classified as a neurotransmitter, and is known to affect mood, body temperature and other important vital functions. An important aspect of serotonin is that it is converted to melatonin, a hormone which gives us good quality sleep. Low serotonin levels have been linked to depression and undesirable mood fluctuations. More recently, other “trace amines”, as they are known, have been found to have similar relationships with mood disorders and addiction (1).
Serotonin is produced when we are exposed to bright light, and it has been indicated that low serotonin levels are associated with chronic fatigue, which I discuss at length in my forthcoming book (due for release in March 2017). However, it is so far not known if it is the fatigue which reduces the serotonin, or the low serotonin which causes the fatigue. What is known is that low serotonin levels have a negative effect on mood, which is why certain antidepressant drugs have been developed which keep serotonin levels higher for longer. These drugs are the SSRIs, which I wrote about in my book Love Your Bones, because they have a negative effect on bone health.
The conversion of tryptophan to serotonin requires magnesium and vitamin B6, so if you are deficient in either of these important nutrients, you could easily end up with a poor conversion rate and low serotonin. Magnesium deficiency is rife in the developed world, with some authors suggesting that 80% of the population is deficient. Because serotonin makes us feel good and it is converted to melatonin, which helps us to sleep, what happens if you interrupt those conversion pathways? The potential for depression and poor sleep patterns. How many people do you know who are affected by these problems?
The enteric nervous system (the network of nerves that are found in the gut, and often referred to as the “second brain”) uses more than 30 neurotransmitters, just like the brain, and in fact 95 percent of the body’s serotonin is found in the intestines. So if our probiotics are out of balance, serotonin levels can be adversely affected and this in turn affects mood. Talk about a gut reaction! Can you see how all of these factors interrelate with each other? And how deficiencies of even one or two micronutrients can have such wide-ranging effects? As always though, there is never “just one thing” that makes the difference. If you are following a diet that includes daily green juices (including wheatgrass), lots of sprouted food, green leafy vegetables, sea vegetables and whole food-based supplements, you’re unlikely to be deficient, but remember that stress runs magnesium out of the body like you wouldn’t believe. So get out in the sun this summer, run around and enjoy it, and pay attention to reducing your stress levels. It’s all important.
1. Pei Y, Asif-Malik A, Canales JJ. Trace Amines and the Trace Amine-Associated Receptor: Pharmacology, Neurochemistry, and Clinical Implications. Front Neurosci. 2016 Apr 5;10:148