The shortest day of the year is just around the corner. So it is an excellent time to look into the effect of long nights on well-being.
In December, the days are short, and the nights are long and dark. I know that many people start to feel the weight of the darkness on their souls right after the holidays when the festivities wane.
My winter experience is that my body’s temperature drops every day by about 6 pm, and I start to yawn. My kids laugh at me and say that my body is as accurate as a swiss clock.
Do you feel the same?
Human beings developed while wearing minimal clothing (if not roaming naked) outdoors. Like plants, humans need a wide range of sunlight waves to promote many life processes.
When sunlight waves make contact with your retina and skin, they send signals to different parts of the body that stimulate the production of serotonin.
What is Serotonin?
Serotonin is a neurotransmitter that helps regulate mood, social behavior, learning, cognition, memory, cardiovascular function, sensorimotor function, pain sensation, appetite, bowel motility, bladder control, sleep, and sexual desire. How cool is that?
Most of the serotonin in your body is produced in the gut with the help of gut bacteria. The serotonin made in the gut is used locally for gut motility. If you struggle with constipation or diarrhea, sun exposure is part of the medicine you need.
Does your digestion feel sluggish in the winter?
Reducing sunlight exposure means less serotonin which leads to lower gut motility (AKA constipation).
Researchers found that skin exposure to sunlight increases serotonin levels in the blood, which makes you feel centered and calm.
Serotonin molecules are relatively large and can not pass from the blood to the brain. Luckily, your brain produces its own serotonin for local use. In the brain, serotonin plays a role in the circadian cycle of sleep and wakefulness.
Serotonin helps regulate human behavior, including mood, anger, aggression, reward, appetite, memory, perception, sexuality, attention, and more. This is why drugs that bind to serotonin receptors (SSRI) are prescribed for many neuropsychiatric conditions.
Researchers demonstrated how shining bright light on the retina can decrease depressive disorders as much as SSRI medications. On the other hand, light deprivation was shown to increase depression.
During the winter months, when there are far fewer hours of light, there is an increase in mood disorders such as depression, anxiety, and bipolar. In many cases, bright light therapy is part of the treatment protocol for these disorders.
What happens when serotonin levels are low?
- Seasonal or chronic depression
- Anxiety and worry
- Panic attacks
- Phobias, obsessions, and compulsive or impulsive behavior
- Low self-esteem
- Aggression and irritability
- Insomnia and sleep cycle disturbances
- Irritable bowel and GI distress
- PMS and hormone dysfunction
- Weight gain and carbohydrate cravings
- Eating disorders
- Chronic pain and muscle pain
- Migraine headaches
- Poor memory and cognitive impairment
- Alcohol abuse
Natural ways to increase serotonin levels
- Add outdoor time to your daily routine.
- The timing of sun exposure is important too. Spending time outdoors in the morning (without sunglasses) supports your circadian cycle. It stimulates melatonin production in the early evening, which leads to a good night’s sleep.
- Movement increases the production of tryptophan, one of the building blocks of serotonin.
As we get closer to winter and you find yourself cuddled indoor with a warm cup of tea your chances of getting more sun exposure goes down and with it serotonin levels. That is why you and many other feel the blues in winter.