Tag Archives: weight control

Uncategorized / 6.12.2016 / No Comment

Sun Exposure, artificial Light and Weight Control

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.[1]

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.[2] 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.

[1] 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.

[2] 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

Uncategorized / 2.13.2016 / No Comment

A new Mechanism of UVB is discovered; it may help Weight-Control and Health.

A most interesting (and very complex) research paper has discovered another way in which sun exposure may contribute to health and also demonstrates a mechanism by which the skin communicates with the brain.[i]

The researchers’ experiment involved using UVB radiation from a sunlamp on the skin of mice and then measuring, among other things, the influence of a signaling mechanism from the skin to the hypothalamus, which increased the quantity of a peptide hormone, known as alpha-melanocyte stimulating hormone (a-MSH). The hormone is important in stimulating pigmentation (melanin) production in the skin. It also has a role in energy balance, feeding behavior and energy homeostasis.[ii]

When the mice were radiated with UVB, their hypothalami received a neural signal which caused them to produce both a-MSH and b-Endorphin, which we all know to be one of the feel-good hormones, also called a reward hormone or natural “upper.” The researchers described this effect as being anorexigenic, meaning that it caused a loss of appetite. It seems that a loss of appetite combined with a natural “upper,” would be a good recipe for effective weight-control. Keeping the metabolism high is important to controlling weight, and the writers made an interesting statement regarding metabolism to end their paper:

“In conclusion, we have established a new paradigm of UVB induced activation of POMC signaling in the hypothalamus with attendant increases of a-MSH and b-END in the plasma which opens up exciting areas of research on the communication between skin and brain and that suggests a role for UVB in regulation of body metabolism.”

This was a recondite paper that took a lot of digging to get through. This would be my translation: “Get some sun exposure or sun lamp exposure; it will increase endorphin levels, rev up the metabolism and help you stay slim and healthy.”

Be safe while you sun, and remember that most sunscreens will stop UVB from doing its job.

There seems to be no end to the positive influence of sunlight on human health and well-being.

[i] Cezary Skobowiat and Andrzej T. Slominski. Ultraviolet B stimulates proopiomelanocortin signaling in the arcuate nucleus of the hypothalamus in mice. Experimental Dermatology, 2016, 25, 120–123.

[ii] Wikipedia. Alpha-Melanocyte-stimulating hormone. https://en.wikipedia.org/wiki/Alpha-Melanocyte-stimulating_hormone. (accessed February 12, 2016)