If you like to sunbathe, you may from now on try to avoid midnight snacks. A study shows that maintaining abnormal feeding rhythms alters the skin’s biological clock , including the effect of an enzyme that protects against harmful radiation from the Sun.
Although more research is needed, the finding suggests that people who tend to dine late may be more vulnerable to sunburn, as well as its long-term effects, such as premature skin aging and skin cancer , according to Dr. Joseph S. Takahashi, a neuroscientist at the University of Texas Southwestern Medical Center. “This finding is surprising, because we did not think that the skin also paid attention to when we eat.”
The study showed that mice given food only during the day, which is an abnormal feeding rhythm for these nocturnal animals, suffered more skin damage when exposed to ultraviolet B (UVB) light during the day than overnight. Contrary to the normal feeding rhythm in humans, which corresponds to the hours of sunshine.
This result came about in part because an enzyme – xeroderma pigmentosum group A (XPA), which repairs UV-damaged skin – changed your daily cycle to be less active during the day.
In contrast, mice that were fed only overnight, as is customary for them, showed no changes in XPA cycles and were less susceptible to daytime UV rays.
The study found that, in addition to disrupting the cycles of the skin-protective enzyme XPA, changing eating times could affect the expression of about 10 percent of the skin’s genes. “We can extract that people who do not have a normal feeding schedule could experience a harmful change in the skin clock , as happened in the mouse,” says Dr. Takahashi.
What’s more, previous studies had already shown that circadian rhythms play an important role in skin biology . However, little had been understood about what controls the skin’s daily clock.
The new research, published in Cell Reports , documents the vital role of feeding times. Scientists focused on this factor because it was already known to affect the daily cycles of metabolic organs, such as the liver.
However, more research is needed to better understand the links between eating patterns and UV damage in people. “It is difficult to translate these results to humans at this time,” according to Dr. Andersen, professor of biological chemistry, who was not involved in the study; “But it is fascinating that the skin is sensitive when eating food.”
Dr. Takahashi, known for his landmark discovery of the Clock gene that regulates circadian rhythms, is investigating other ways in which meal times affect the biological clock. A study in early 2017 reinforced the idea that the time of day you eat food is more critical to weight loss than the number of calories you eat. Now, he’s conducting long-term research that measures how diet affects aging and longevity.
