Visiting the beach? Going on a hike? Be ready: Men will be hungrier!
According to recent research from Tel Aviv University, exposure to the sun makes men more hungry but not women. The research, which was conducted using lab models, reveals how the metabolic mechanism is activated differently in men and women. According to the researchers, sun exposure in males of both animal species and humans triggers a protein called p53 to repair any DNA damage that may have been done to the skin as a result of the exposure.
Ghrelin, a hormone that increases hunger, is produced by the body in response to the activation of p53. The hormone estrogen prevents the interaction of p53 with ghrelin in females, which prevents the urge to eat after exposure to the sun.
Professor Carmit Levy and Ph.D. student Shivang Parikh of the Department of Human Genetics and Biochemistry at TAU’s Sackler Faculty of Medicine led the groundbreaking study. It was carried out in partnership with numerous Israeli and international researchers, including Tel Aviv Sourasky (Ichilov), Assuta, Meir, and Sheba Medical Centers, as well as Dr. Yiftach Gepner and Dr. Lior Bikovski from TAU’s Sackler Faculty of Medicine and Professor Aron Weller from Bar-Ilan University. The study was published in the renowned journal Nature Metabolism.
The study’s epidemiological data, which included self-reports from students who had spent time in the sun, were gathered over the course of a yearlong survey of about 3,000 Israelis of both sexes about their eating habits. This data was combined with the findings of a genetic study performed in a lab model. The results show that both in laboratory models and in people, the skin is a key regulator of energy and appetite (metabolism).
The researchers explain that there is a dramatic metabolic difference between men and women, impacting both their health and their behavior. However, so far it has not been established whether the two genders respond differently to environmental triggers such as exposures to the sun’s UV radiation.
Professor Levy: “We examined the differences between men and women after sun exposure and found that men eat more than women because their appetite has increased. Our study was the first gender-dependent medical study ever conducted on UV exposure, and for the first time, the molecular connection between UV exposure and appetite was deciphered. Gender-dependent medical studies are particularly complex since twice the number of participants are required in order to find statistically significant differences.”
Professor Levy concludes: “As humans, we have cast off our furand consequently, our skin, the largest organ in our body, is exposed to signals from the environment. The protein p53, found in the skin, repairs damage to the DNA caused by sun exposure, but it does more than that. It signals to our bodies that winter is over, and we are out in the sun, possibly in preparation for the mating season. Our results provide an encouraging basis for more research, on both human metabolism and potential UV-based therapies for metabolic diseases and appetite disorders.”
Reference: “Food-seeking behavior is triggered by skin ultraviolet exposure in males” by Shivang Parikh, Roma Parikh, Keren Michael, Lior Bikovski, Georgina Barnabas, Mariya Mardamshina, Rina Hemi, Paulee Manich, Nir Goldstein, Hagar Malcov-Brog, Tom Ben-Dov, Ohad Glaich, Daphna Liber, Yael Bornstein, Koral Goltseker, Roy Ben-Bezalel, Mor Pavlovsky, Tamar Golan, Liron Spitzer, Hagit Matz, Pinchas Gonen, Ruth Percik, Lior Leibou, Tomer Perluk, Gil Ast, Jacob Frand, Ronen Brenner, Tamar Ziv, Mehdi Khaled, Shamgar Ben-Eliyahu, Segev Barak, Orit Karnieli-Miller, Eran Levin, Yftach Gepner, Ram Weiss, Paul Pfluger, Aron Weller and Carmit Levy, 11 July 2022, Nature Metabolism.