biology zoology blog benno meyer wrinkle

“Wrinkle-wrinkle, au revoir”

How I wonder what you are

I have recently been reading about wrinkles. Not because I am worried about my wrinkles (I actually think wrinkles can make a face look more interesting than if it was “as smooth as a baby’s bottom”), but because so many people here in East Asia seem terrified of getting wrinkles and avoid an exposure to direct sunlight through face masks, parasols, summer hats, lotions, creams, etc. The scientific literature on wrinkles includes information on skin structure and function, biochemical and physiological reasons to develop wrinkles, but I couldn’t find anything about perhaps the most obvious reason: you get older, you shrink!  As we age, our height diminishes. During the time I passed university examination I was 184 cm tall; now I am 181 cm tall. People who have spent some time in the space station circling around our planet Earth under zero gravity conditions reverse that trend and are a little bit taller when they return to Earth. An apple that ages shrinks and becomes wrinkly. And humans  – how about us?

Wrinkles consist of more or less deep furrows and bulges and they usually develop along locations of microlines in the skin. The latter form a polygonal network of fine lines easily visible on the outer skin layer (the epidermis) with a magnifying glass. Under the epidermis lie the dermis and hypodermis with their stabilizing connective tissue component proteins collagen for structural integrity and elastin for flexibility and plasticity. And, not to forget, there is hyaluronic acid in the skin with its multiple functions. All the skin layers are associated with underlying lymphatic vessels along with perilymphatic and subcutaneous fat tissue, known as panniculus adiposus and p. carnosus. What is most damaging and a cause of the skin to age is oxidative stress, in other words free oxygen radicals. These radicals are highly reactive and may be produced by the breakdown of double-bond fatty acids following an exposure to UV-radiation. There are, of course, ways the skin tries to protect itself: a higher sebaceous gland density of the skin is correlated with shallower wrinkles, but as the pillars of the skin (like collagen and hyaluronic acid) slowly diminish and the skin becomes drier the decline in skin cell renewal of older people can only be slowed down with a nutrition that is rich in vitamins and anti-oxidants.

What matters also are the genetic factors and how rapidly a person ages. In addition, smoking and heat are often mentioned as wrinkle-promoting, and so is lack of sleep; in fact, anything that causes skin to become dehydrated. However, there is one cause that is related to facial expressions.  Grooves on the forehead during thinking, or wrinkles during laughter, or the vertical lines between your eyes during squinting to see more clearly: such lines can become permanently visible as expressive wrinkles. There is generally not terribly much that an ageing person can do to avoid getting wrinkles, but there is one dog breed (the “Shar-pei”), in which the wrinkles disappear with age. For other and much bigger animals with wrinkled skins, the wrinkles can actually be an advantage as they can hold moisture that can then evaporate from a larger surface area and in this way lead to the cooling of the wrinkled individual. This suggestion has often been advanced to explain the folds and wrinkles of the skins of elephants and rhinoceroses. However, fact is that any animal (other than a Shar-pei dog) develops wrinkles as it ages, especially around the joints. But because animals are covered in fur we tend to overlook their wrinkles  -with one exception: the beautiful, pain-free naked mole rats. Their incredibly wrinkled bodies help these subterranean, naked rodents to turn around in their narrow tunnels and navigate corners with ease.

To return to my earlier statement that we shrink as we age and that space travellers are taller when returning to Earth: my hypothesis is that they would not only be slightly taller but also less wrinkled (provided they got enough sleep and had good vitamin-rich food while at the space station). In any case: Every wrinkle has a story to tell and as for me, there will be a lot more stories when I’m older.

© Dr V.B. Meyer-Rochow and, 2020.
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