Science evolves! It turns out serotonin is not the happy hormone, but rather a stress hormone. Elevated serotonin is linked to weight gain, sleep disturbance, anxiety, agitation, sexual dysfunction, an increase in the risk of diabetes, and more.
Psychology Today breaks the serotonin confusion down.
“As it turns out, low serotonin in depression is a myth. But the real link between serotonin and depression is even more surprising. “The evidence is pretty clear,” said Hollon. “There’s not a deficit—there’s an excess.” He described findings from a study that measured metabolite levels from blood in the brain, which indicate how much serotonin the brain is using. Results from this study revealed that serotonin levels were elevated among those with clinical depression, and returned to normal levels following medication treatment. Other studies (e.g., Gjerris et al., 1987, and Sulllivan et al., 2006) using different methods have found similar results. These findings sound paradoxical, given that depression medications tend to increase the amount of serotonin in the synapse, at least initially. But Hollon explained that “within a week to ten days, you increase the amount of serotonin so high that the regulatory mechanisms push back.” As a result, serotonin levels fall. “It’s like holding a match up to a thermostat to turn the furnace down,” said Hollon. “You’re tricking the system into kicking back in and regulating” serotonin levels.
High levels of serotonin in depression make more sense when we realize that serotonin is not the “feel-good neurotransmitter,” as has often been claimed based on its involvement in depression; that role is played by the endogenous opioids (as the name suggests) like endorphins. According to Hollon, “Serotonin is the energy transfer regulator. It moves you back and forth between approach and avoidance behavior.”
So then what is serotonin? Here’s what you need to know about this mysterious hormone.
-Serotonin elevates under stress (stress mediators could be emotional stress, darkness, exercise, nutrient deficiencies, or lack of sleep).
-Vitamin D and the omega-3 fatty acids control serotonin synthesis and action.
-95% of serotonin is produced in the gut.
-Serotonin can increase gut motility–this alone can help someone “feel” better.
-Serotonin contributes to the nerve damage seen in multiple sclerosis and Alzheimer’s disease. Estrogen activates mast cells to release histamine and serotonin, and activated mast cells can produce brain edema and demyelination.
-Serotonin can increase histamine, estrogen, prolactin, and cortisol.
-Serotonin inhibits mitochondrial respiration.
-Although SSRIs do increase serotonin, that is not the source of why people feel better. SSRIs make you feel good not because of increased serotonin, but rather as a result of them increasing transmitter substances, and increasing brain progesterone and other steroids, which is what lifts the mood. Interestingly enough, some drugs that lower serotonin can be effective against depression-like quetiapine or cyproheptadine.
-Serotonin is high in hibernating animals, as it decreases the metabolic rate. This is needed for hibernating animals because they will not be eating for a long time.
-Serotonin can play a role in migraines, anxiety, blood clotting, and nerve cell damage.
-Serotonin can inhibit the conversion of T4 (the thyroid hormone called thyroxin) to T3 conversion, which lowers metabolism.
-Stress and cortisol can increase serotonin.
What can increase serotonin? Certain medications like SSRIs, birth control, opioids, cough medicine, cocaine, high tryptophan diets, hard-to-digest nuts, seeds, grains, and stress can increase serotonin.
How can one decrease serotonin? Reducing stress, lowering consumption of tryptophan foods and hard-to-digest foods, using coconut oil, progesterone, gelatin, niacinamide, correcting thyroid function, and saturated fat can help to decrease serotonin.
Cortisol is a stress hormone and Vitamin D opposes cortisol and can be thought of as an anti-stress hormone. Vitamin D antagonizes cortisol and inhibits serotonin synthesis. When vitamin D levels are low it has been found by multiple (both animal and human) studies that baseline cortisol increases, dopamine decreases, and 5-HIAA (a metabolite of serotonin) increases. In other words – vitamin D deficiency mimics stress.
- As Vitamin D opposes cortisol, when it is low, it can lead to elevated parathyroid hormone, prolactin, and cortisol.
- Daily sunlight exposure and foods high in vitamin D are key.
- On a blood test, a level of 50-70 ng/ml of 25-hydroxyvitamin D is an optimal range.
The connection between vitamin D and stress is especially interesting when examining opioid addiction.
“The lab data suggesting that vitamin D deficiency increases addictive behavior was supported by several accompanying analyses of human health records. One showed that patients with modestly low vitamin D levels were 50 percent more likely than others with normal levels to use opioids, while patients who had severe vitamin D deficiency were 90 percent more likely.
Another analysis found that patients diagnosed with opioid use disorder (OUD) were more likely than others to be deficient in vitamin D. Back in the lab, one of the study’s other critical findings could have significant implications, says Fisher. “When we corrected vitamin D levels in the deficient mice, their opioid responses reversed and returned to normal,” he says. In humans, vitamin D deficiency is widespread, but is safely and easily treated with low-cost dietary supplements, notes Fisher.
While more research is needed, he believes that treating vitamin D deficiency may offer a new way to help reduce the risk for OUD and bolster existing treatments for the disorder. “Our results suggest that we may have an opportunity in the public health arena to influence the opioid epidemic,” says Fisher.
Grey hair is a quintessential part of aging. But have you ever wondered how these hairs come to be?
As we age, we encounter more stressors (nutrient deficiencies, toxins in the environment, emotional stress, less sleep, and so on. One study revealed the striking link between stress and grey hair. “…Stress can have a variety of negative effects on the body. The idea that acute stress can cause hair to turn gray is a popular belief. But until now, that link wasn’t scientifically proven. The mice were exposed to three types of stress involving mild, short-term pain, psychological stress, and restricted movement.
All caused noticeable loss of melanocyte stem cells and hair graying. Having established a link between stress and graying, the scientists then explored several potential causes. They first tested whether immune attack might be responsible for depleting melanocyte stem cells. But stressing mice with compromised immune systems still led to hair graying.
The team then investigated the role of the stress hormone corticosterone, but altering its levels didn’t affect stress-related graying. The researchers eventually turned to the neurotransmitter noradrenaline, which, along with corticosterone, was elevated in the stressed mice. They found that noradrenaline, also known as norepinephrine, was key to stress-induced hair graying.
By injecting noradrenaline under the skin of unstressed mice, the researchers were able to cause melanocyte stem cell loss and hair graying. Noradrenaline is produced mostly by the adrenal glands. However, mice without adrenal glands still showed stress-related graying. Noradrenaline is also the main neurotransmitter of the sympathetic nervous system, which is responsible for the “fight-or-flight” reaction in response to stress. The team ultimately discovered that signaling from the sympathetic nervous system plays a critical role in stress-induced graying. Sympathetic nerves extend into each hair follicle and release noradrenaline in response to stress. Normally, the melanocyte stem cells in the follicle are dormant until new hair is grown. Noradrenaline causes the stem cells to activate.”
People’s grey hairs sometimes naturally regain their original color, typically when individuals feel less stressed.
Lab mice go grey when stressed and the same thing seems to occur in people. It has long been assumed that once hairs turn grey, they stay that way. But Martin Picard at Columbia University in New York and his colleagues discovered by chance that hair greying sometimes naturally reverses.
One study looked at the “hair of 14 healthy men and women from different ethnic backgrounds with an average age of 35. They plucked 397 hairs from the participants and studied them under a microscope. They identified hairs that were turning grey by looking for those that were grey at the roots while still coloured at the tips, as new hair grows from the scalp.
To their surprise, the researchers discovered some hairs showed the opposite pattern – they were coloured at the roots and grey at the tips – suggesting they were reverting from grey to their original colour. Because hair grows at a fixed rate of 1 to 1.3 centimetres per month, the team was able to trace these colour transitions back to specific life events. The reversals tended to correlate with periods of reduced stress. For example, it occurred in one participant when he went on a two-week holiday and in another after she recovered from the stress of her marriage breakdown. It is feasible that stress reductions could trigger a reversal of hair greying, says David Fisher at Harvard University.”
To simplify things a bit more, stress and aging go hand in hand. So if you’ve ever noticed that you have a few new white hairs sprouting after a stressful time, this is probably why.
What else is going on?
- Greying hair is linked to elevated tryptophan in the blood. In white hair, the amount of tryptophan is higher than in hair of any other color.
- Tyrosinase, a copper-containing enzyme, is important for regulating melanin production, which dictates hair pigmentation. If the body is in a state of copper deficiency, the color of the hair can change. Copper is a catalyst for hair color so make sure to increase copper consumption from foods in shellfish, shrimp, clams, lobster, and squid.
While grey hair may also have links to genetics, in many cases it is lifestyle-related and a clue to look further into oneself. Premature gray is potentially a cause of concern because some studies show a significant association between grey hair and coronary artery disease.