Sun Exposure, artificial light and weight control. Marc Sorenson, EdD… Sunlight Institute
Sun exposure gives life and has so many positive effects, including anticancer, anti-heart disease, and anti-osteoporosis. Unnatural light, however can do exactly the opposite. In the case of obesity, artificial light at night (ALAN) can lead to weight gain, according to a study in the International Journal of Obesity.
The hormone melatonin works in conjunction with serotonin during each daily physiological cycle, known as the circadian rhythm. Serotonin is a natural “upper” that awakens our senses and prepares us for our workday. Then, when the rhythms are properly synchronized, as evening comes, serotonin decreases and melatonin, a sleep inducer, takes over so that we can sleep soundly and awake refreshed as daylight and serotonin once more take over. However, a monkey wrench is often thrown into the works. It is called artificial light at night (ALAN), and it may be one of many factors that lead to obesity. ALAN inhibits melatonin production, a factor in both obesity and cancer.
The researchers looked at satellite images of 80 countries, assessed the amount of ALAN emitted from each country and then compared the rates of obesity in each. The data was adjusted to take into consideration the differing dietary patterns in each country, as well as the urban vs rural population and other factors that would influence obesity.
The results showed, that after all adjustments, ALAN emerged as a prominent predictor for obesity.
So how does this relate to sun exposure? One of my recent posts noted the results of research on early morning sun exposure and obesity, noting that early sun exposure inhibited obesity dramatically. So not all light is good. Light at night is harmful; early morning sun exposure is wonderful. And if one wants to remain slim, it is imperative to eschew junk food, exercise and get plenty of non-burning sun exposure.
 Rybnikova NA, Haim A, Portnov BA. Does artificial light-at-night exposure contribute to the worldwide obesity pandemic? International Journal of Obesity. Int J Obes (Lond). 2016 May;40(5):815-23.
 Reid KJ, Santostasi G, Baron KG, Wilson J, Kang J, et al. Timing and Intensity of Light Correlate with Body Weight in Adults. PLoS ONE 2014 9(4): e92251. doi:10.1371/journal.pone.0092251
By Marc Sorenson, EdD, Sunlight Institute…
We all know that high sunlight exposure in adults leads to higher vitamin D levels. However, a most interesting piece of research also shows that your birth month has a considerable influence on vitamin D levels. In an Italian study, it was found that those who were born in winter, rather than spring and summer, were 11% more likely to develop vitamin D deficiency later in life.[i] This is an important finding, since many diseases are related in one way or another to season of birth. For example, a greater risk of obesity risk is observed in Canadians born in winter. Nevertheless, other factors such as inactivity are more important than season of birth.[ii]
This is another study that ties sunlight to vitamin D. But the question may still be asked: Is the relationship of birth seasonality to disease due to vitamin D or sunlight, or both? Whatever the answer, sunlight is the factor that makes vitamin D, so safely soak up the sun whenever you have the opportunity, and when it is too cold or overcast, safely use a sun lamp or tanning bed.
[i] Lippi G, Bonelli P, Buonocore R, Aloe R. Birth season and vitamin D concentration in adulthood. Ann Transl Med. 2015 Sep;3(16):231.
[ii] Wattie N1, Ardern CI, Baker J. Season of birth and prevalence of overweight and obesity in Canada. Early Hum Dev. 2008 Aug;84(8):539-47.
By Marc Sorenson, EdD, Sunlight Institute
Are you suffering from anxiety disorder, but fear taking drugs? Your fear is well-founded. It has been shown that a class of drugs called anti-anxiety drugs, i.e. valium and Xanax, and sleep aids like Ambien, Sonata and Lunesta lead to increased risk of death.[i] During 7.6 years, and after controlling for other factors such as sleep disorders, anxiety disorders and other psychiatric illnesses, it was found that the risk of dying was 3.46 times higher in those who took the drugs compared to those who did not. Considering the material we have posted on this site regarding brain disorders, insomnia, and sunlight, it seems reasonable to believe that a better and less dangerous anxiety-treatment option would be regular sunlight exposure.
Research from Denmark has shown that morning light, made to mimic daylight, relieves anxiety by reducing the activity of the brain’s fear center.[ii] The efficacy of the light treatment was based on the intensity of the light: the greater intensity, the greater the effect.
Another scientist, Dr Klaus Martiny, commented on the above study and noted that morning light improves sleep. “A lack of daylight disrupts some hormonal processes in our body that regulate our circadian rhythm. This can result in a shift in circadian rhythm, so that people go to sleep later and later in the evenings, and this shift is associated with an increased risk of depression.”[iii]
Martiny suggested that a good rule of thumb is to go to sleep before midnight and awaken before 8:00 AM. However, we discussed in the post on obesity that the earliest morning sunlight was associated with a remarkably lessened risk of obesity, which was also attributed to resetting the circadian rhythm. We therefore suggest that a better rule of thumb is to be outside for a half-hour when the sun rises each morning.
Get your morning sunlight, your midday sunlight and your afternoon sunlight. Sunlight is the great healer.
[i] Weich S, Pearce H, Croft P, Singh S, Crome L. et al. Effect of anxiolytic and hypnotic drug prescriptions on mortality hazards: retrospective cohort study. BMJ 2014;348:g1996.
[ii] Christensen B. Morning light relieves anxiety. Science Nordic 2014. http://sciencenordic.com/morning-light-relieves-anxiety Accessed August 8, 2015.
[iii] http://sciencenordic.com/morning-light-relieves-anxiety. Accessed August 8, 2015