Day after day, our skin endures a barrage of harsh ultraviolet radiation, irritating chemicals and toxic ozone gas. For an organ not much thicker than the head of a pin, that assault is a lot to take, and over time it can accelerate visible aging. Most assumed that this aging was inevitable, but a new series of studies seems to indicate that age may not be destiny after all.
By monitoring subtle shifts in the biochemical composition of skin cells, researchers at Estée Lauder, a global leader in prestige beauty, have revealed that, like many other parts of the body, skin has a daily rhythm that tends to weaken with age. Scientists have shown that skin can be returned to a more youthful rhythm and that visible signs of aging could be reduced.
“The work provides a whole new view of how skin should be looked at,” Paolo Sassone-Corsi, Director of the Center for Epigenetics and Metabolism at the University of California, Irvine, says. “It is not an inert tissue, but instead is extremely active in its metabolism.”
The Hidden Rhythm of Skin
Since the 1970s, scientists have known that the characteristics of young and healthy skin change over the course of the day. In waking hours, skin acts as a barrier to all manner of external threats, from radiation to irritants, leaving it taut and dry. At night, skin repairs the damage sustained in the previous day. By morning, it is softer, more hydrated and ready to face the day’s irritants as a restored barrier.
For Estée Lauder, this biological rhythm begged better understanding. In 2007 the company recruited Nadine Pernodet from the Materials Science and Engineering department of Stony Brook University, where she was investigating how skin function is altered by epigenetic changes—heritable changes in tissue that do not involve altering the cell’s DNA sequence. At that time, there was continuing research into the science of circadian rhythms, including those of various organs. Three researchers were awarded the 2017 Nobel Prize in Physiology or Medicine for work in this area. But little was understood about the circadian rhythms of skin.
At first, Pernodet and her team studied human skin cells grown from younger and older subjects in the lab. They found evidence of circadian rhythms in lab-grown younger cells, but not in older ones, an indication that repair efficiency degrades with age. That insight helped guide the reformulation of Estée Lauder’s Advanced Night Repair Synchronized Recovery Complex in 2009. But, for Pernodet, questions remained.
