Posted on Aug 18, 2017, 9 a.m.
Study reveals that those who eat late at night may be more vulnerable to sunburn and longer-term effects such as skin aging and skin cancer
Most people think the application of sunscreen with a high SPF is the best way to combat the sun's harsh rays. Scientists might have pinpointed another way to prevent sun damage: consuming food at conventional eating times. A recent study conducted at UC Irvine and the O'Donnell Brain Institute determined eating at odd times disturbs the skin's biological clock. An abnormal eating schedule also disrupts the daytime potency of a particular enzyme that guards against the sun's damaging ultraviolet radiation. Mice were used for the study yet the results might hold true for humans. The study results were detailed in a recent issue of Cell Reports.
What the Findings Mean
The study's results suggest those who eat late at night are more vulnerable to the sun's harsh UV radiation. These individuals face a heightened risk for sunburn, skin aging and even skin cancer. It is quite a surprising finding. Few would have guessed an odd eating schedule would increase the chance of skin cancer following sun exposure. The finding shows the skin is paying close attention to the times at which one eats.
Details of the Study
Mice were provided food during the day. This is an abnormal eating time for mice as they are naturally nocturnal. This eating schedule resulted in more skin damage when subjected to ultraviolet B light during the daytime hours than was experienced during the night. This outcome is partially attributable to the shifting of xeroderma pigmentosum group A's (XPA) shifting of its daily cycle for less activity during the daytime hours. This enzyme is responsible for repairing skin damaged by UV rays. The mice that ate during their typical evening hours did not exhibit altered cycles of the enzyme. These mice weren't as vulnerable to daytime UV rays.
About the Findings
The findings show a normal eating schedule better protects the skin against harmful UV rays during the day. An odd eating schedule shifts the skin's clock and reduces protection against UV rays. Prior studies showed the body's circadian rhythms played strong roles in skin biology. Yet little was understood about the mechanisms that affect the skin's clock. The scientists who conducted the study outlined in this article keyed in on the importance of feeding time as it was previously identified as an important factor that affects daily cycles of certain metabolic organs like the liver.
Aside from the findings outlined above, the study also determined that altering one's eating schedule affects the manner in which around 10 percent of skin genes are expressed. Additional research will be necessary to form a full understanding of the connections between eating patterns and UV-inflicted damage. In particular, the manner in which XPA cycles are impacted must be studied in-depth.
Are the Findings Applicable to Human Beings?
At the moment, it is difficult to translate the study's findings to human beings as mice biology is different than that of a person. However, it is quite interesting to note that the skin of mice is sensitive to the time at which food is consumed. There is a reasonable chance human skin is also impacted by the timing of food consumption just like that of mice. We will likely find out if this is true as additional research is performed in the coming years.
Hong Wang, Elyse van Spyk, Qiang Liu, Mikhail Geyfman, Michael L. Salmans, Vivek Kumar, Alexander Ihler, Ning Li, Joseph S. Takahashi, Bogi Andersen. Time-Restricted Feeding Shifts the Skin Circadian Clock and Alters UVB-Induced DNA Damage. Cell Reports, 2017; 20 (5): 1061 DOI: 10.1016/j.celrep.2017.07.022