If you can't bear to face your inbox before your first cup of coffee, you'll sympathize with cells in your body that are better equipped to face some challenges at certain times of day. Carcinogens, such as ultraviolet radiation, may be one such challenge. Can we lower our cancer risk by limiting our carcinogen exposure to certain hours of the day?
Circadian rhythms are day-long cycles that ebb and flow like tides within our bodies. We use the sun to keep our internal clocks calibrated. But even if left in a dark room for days on end, our bodies maintain their rhythms. Our internal temperatures, levels of circulating hormones, and activity of various genes within our cells all rise and fall throughout the day.
One of the genes that follows a daily cycle is responsible for making a DNA-repair protein called XPA. When your DNA is damaged, a molecular task ...
