The Mechanics of Wrinkles
No one wants to talk about it, but it happens to everyone and is almost as certain as death and taxes: aging. Unless you have the luck of amazing genes, aging - and most notably, wrinkles - is nearly unavoidable. Wrinkles are not only a part of aging, but also make a difference in how we take care of our skin, what cosmetics we choose and even the clothes we wear.
But what causes wrinkles? Researchers at the University of Southampton's Centre for Advanced Tribology in conjunction with scientists from the Biomechanics and Mechanobiology Laboratory at the University of Cape Town set out to answer this question using a very surprising approach: biomechanics.
Scientists from the schools created a series of quantitative computer models to create 3-D models of wrinkles to help skin care researchers identify the physics involved in their development. The researchers hope that by identifying these characteristics, they could help to advance the development of new approaches to both treat existing wrinkles and prevent new ones from forming.
One primary reason that wrinkles develop is dehydration; low levels of moisture cause tiny lines to develop in the topmost layer of the skin, known as the stratum corneum.
The stratum corneum plays a critical role in the body by serving as a biochemical barrier. According to the study authors, this very thin layer made up of dead skin cells bound by lipids also plays a role in determining the formation of wrinkles.
"When the stratum corneum becomes dry, it becomes stiff. So, when the skin moves, these tiny wrinkles in the stratum corneum will grow," said Dr. Bill Johnson.
Johnson is a Dallas, Texas, cosmetic physician who often sees individuals who want to get rid of their wrinkles.
"Wrinkles make people look older prematurely, so naturally, people want to erase them," Johnson said.
If the stratum corneum stays dehydrated for long periods, these wrinkles can develop into larger and more visible wrinkles.
Older people are not the only age group at risk of developing wrinkles.
"Keeping the skin hydrated is critical to preventing wrinkles at any age," Johnson said. "People can keep the skin hydrated by drinking enough water and using quality skin care products, particularly those with hyaluronic acid."
If the skin stays dry, tiny wrinkles continue to grow with movement.
"Continuing to make facial expressions will further cause the development of new wrinkles and make existing wrinkles deeper and more visible," Johnson said.
Facial expressions such as laughing, smiling and frowning cause the development of wrinkles and creases around the mouth and nose.
Other expressions, such as squinting, glaring and furrowing of the forehead cause crow’s feet to develop near the eyes and between the eyebrows.
The researchers hope to use their biomechanical models to identify the patterns and morphologies involved in wrinkle development. Understanding these elements can also help to predict how aging skin will react in different environments.
In addition to dehydration, wrinkles can develop because of regular and prolonged sun exposure.
"The sun causes the breakdown of two key elements of skin health: collagen and elastin. When collagen and elastin are destroyed, the skin loses its ability to stretch and retract," Johnson said.
Other factors that contribute to the development of wrinkles and other signs of aging include behavioral factors like smoking and alcohol consumption.
"Smoking and drinking dehydrate the skin, which contributes to wrinkles," Johnson said.
Genetics and the use of certain medications also weigh in to wrinkle development.
"If your mom or Aunt Mary had wrinkles, you are likely also to develop wrinkles," Johnson said.
University of Southampton. "Going skin deep to explore what causes wrinkles." ScienceDaily. ScienceDaily, 28 February 2018.