We all know that getting outside and enjoying some sunshine can really perk you up. Most of us don’t get enough sunlight since we spend so much time indoors. Even when we are in the sun we usually wear sunglasses to protect our eyes, but this unfortunately decreases the amount of light we need to keep our brain hormones in a healthful state.
Ideally, light exposure during the day sends signals from our retina to the hypothalamus and pineal gland. These glands secrete hormones that regulate sleep, mood, body temperature, libido, appetite.
When we don’t get enough light exposure during the day (particularly when we awaken in the morning), melatonin levels rise and serotonin levels fall. This hormonal disruption can cause sleeping difficulties, fatigue and depression.
Researchers have found that when individuals are exposed to a bright white light (“light therapy”), they feel less depressed, have more energy and sleep better.
The Science:
Most of the published studies administered light therapy using a light box, a device that shines a full spectrum, white light (with a rating of 10,000 LUX) onto the eyes of the user. To get the best results, it should be used for 30 minutes each morning (within 30 minutes from awakening.)
Not all light boxes are the same. The most effective devices emit light in a similar spectrum to the sun (without the harmful UV waves.) The most potent, in terms of hormonally stimulating, shine most of their light in the wavelength range of 460 nanometers (blue light) to 550 nanometers (green light.)
The distance to the light box is also important, as the intensity of light hitting your eyes matters. Each light box comes with instructions on how to position the device.
Depression Study:
By the end of an 8-week study:
- Light therapy reduced depression scores (Montgomery-Åsberg Depression Rating Scale or “MADRS”) by 33%
- Taking 20 mg of Prozac (fluoxetine) each day reduced depression scores by 29%
- Using both, reduced scores by 75.9%
Fatigue Study:
- Compared with dim/red light exposure, bright/white light exposure for 4-weeks significantly improved fatigue scores.
Products Used In The Above Studies:
- Carex Day-Light Classic (rated at 10,000 LUX)
- Litebook Edge (rated at 10,000 LUX)
The Bottom Line:
If you suffer from depression or fatigue, get some sunlight each morning or consider trying one of these devices.
