COULD EXPOSURE TO SUNLIGHT OVER THE SUMMER lead to an increase in eating? The strange phenomenon occurs, but only in men. That is the conclusion of a study of data obtained from an Israeli health survey. Today we look at how sunlight triggers increased eating.
Researchers from Columbia University (USA) and the Institute for Diabetes and Obesity (Germany) describe their analysis of the Israeli data. Previous research showed that sunlight exposure could encourage vitamin D production. On the other hand, too much sunlight is associated with skin cancer, including melanoma.
But did you know that sunlight could lead to increased eating (at least among men)? Let’s turn to a study from Madrid, Spain.
Sunshine and appetite
While analyzing how sunlight causes skin cancer in mice, researchers noticed that male mice grew more hungry when exposed to ultraviolet (UV) light. Might the same association be true in humans?
Researchers got data from a governmental health and nutritional questionnaire sent to individuals across Israel. Here are the research findings:
Men tended to eat more during the summer months (compared with other seasons), consuming 15 percent more calories during summer. The author attributes the increased calorie consumption to sun exposure. There appeared to be no sunlight-associated increase in food intake among women.
Enter the hormone ghrelin, the so-called hunger hormone. We produce this substance in the stomach (and sometimes in the brain, pancreas, or small intestines).
Ghrelin travels via the bloodstream, activating nerve cells (neurons) in the hypothalamus and other brain structures. Ghrelin rises when we are hungry or right before we consume a meal.
Ghrelin levels in male mice rose after the researchers exposed male mice to ultraviolet-B light. These mice became more hungry.
Ghrelin secretion also occurred in human skin samples from male volunteers exposed to ultraviolet light. Following UV light exposure, hunger levels in the males rose.
For females, estrogen interferes with the ghrelin action and food-seeking behavior associated with ultraviolet-B exposure.
I don’t know if anything is actionable, but I wanted to share this interesting research finding with you. Thank you for joining me today for this brief look at how sunlight triggers eating.
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
