I once talked with a lady who told me, “I have been suffering with depression for two years.” As we talked, I discovered she wasn’t always depressed. She noted that after being exposed to as little as an hour or so of sunlight on the weekends, her depression left. Why is sunlight so important? Scientists have discovered that sunlight, registered through the eyes, increases serotonin in the brain. We need serotonin to feel in a good mood and to help resolve depression. Dr. Lambert at the Baker Heart Research Institute, Melbourne, Australia, found that the amount of serotonin in the blood carried by the jugular vein to be eight times greater on a bright day than a dull day.[ 1] Its important to note that the light intensity indoors with artificial lighting is often less than that experienced outside on a dull day. Most of us spend nearly all our time inside, thus, perpetually experiencing much lower light intensity than we would if we were outside even on a dull day. As a result, our brain serotonin levels may drop significantly. Additionally, the brain appears to make significantly more serotonin in the summer compared to winter. In the summertime, the blood coming from the brain has seven times more serotonin than it has in the winter under similar conditions. Sunlight in summer is of greater intensity than in winter, and more intense light entering the eyes stimulates greater manufacture of serotonin. What does all this mean? If you have been suffering with depression and/ or lack of energy, these symptoms may improve as you increase your exposure to sunlight. If possible, get at least thirty minutes of bright sunlight first thing in the morning. Morning sunlight is most beneficial. However, even walking outside during a fifteen-minute break morning and afternoon will also help raise serotonin. Make a habit of spending more time outside every day. If you have limited time, try to go outside when the sunlight is most intense. The increase in serotonin in your brain is automatic and immediate upon exposure to sunlight. However, the serotonin your body makes today will not last until tomorrow, so you need outdoor sunlight exposure daily! On cloudy days and during winter, spend more time outside because light intensity is reduced. Be careful never to burn your skin or even to turn it pink. It is sunlight entering your eyes that raises serotonin; your skin can remain completely covered. Of course, never look directly at the sun and always follow your doctor’s recommendation about sunlight exposure. Even if you don’t suffer from depression, sunlight is essential to good health—both mental and physical. Make sure you get enough sunshine! [1]. G. W. Lambert, “Effect of Sunlight and Season on Serotonin Turnover In the Brain,” The Lancet, December 7, 2002, 36 (9348): 1840-1842.”


— Dr. Arnott’s 24 Realistic Ways to Improve Your Health by Tim Arnott