Why are visible signs of aging—fine lines, wrinkles, sagging, roughness and scaling, and overall discoloration—apparent in someone thirty years old and virtually absent in someone fifty-five years old? You may think that the fifty-five-year-old with the youthful, vibrant skin has great genetics and stays out of the sun, which would be the easy answer. But recent advances in the science of aging skin reveal that the exclusivity of wrinkles to genetics and sun may be a bit simplistic. That’s not to say that genetics and sun exposure don’t matter—they absolutely do. However, other factors are also at play. Scientific advances show that diet and lifestyle exert significant control over genes. The foods we eat, the beverages we drink, and the stressors we experience can all combine to influence what is called genetic expression.
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Environmental factors affecting genetic expression include diet, stress, history of trauma, mental health, and toxic exposures. These factors all interact with genes as we proceed through life. Countless examples in medical literature show how environmental factors influence genetic expression. Twin studies routinely show that, despite genetic predisposition, one twin will often not experience a disease or chronic medical condition, while the other will succumb to it. The influence of lifestyle, diet, stress, and environmental toxins has been documented in all aspects of medicine— from mental health disorders to gastrointestinal disease—and, of course, in dermatological conditions.
Other people use the condition of your skin as a visual cue to assess chronological age, health, and vitality. While this fact may be dismissed as just another example of our youth-obsessed culture and the prevalence of insidious ageism, the reality runs deeper. Evolutionary psychologists have demonstrated time and time again that both sexes are wired to visually assess health and vitality. So when it comes to the visible signs of facial aging, we are fairly good at sizing up overall internal health. Using those visual cues as a surrogate marker for internal health turns out to be quite reliable.
Harry Daniell, MD, an internist working in Redding, California, uncovered an interesting link between internal disease and wrinkles in a study published in the Annals of Internal Medicine (1971). For years, he was convinced that smoking caused facial wrinkles in his patients. After a one-year study of more than one thousand community residents, aged thirty to seventy, Daniell did indeed show that smoking greatly increased the risk of wrinkles—even more than sun exposure, according to his results.
Yet one intriguing finding was, at the time, almost inexplicable. Among male smokers over age fifty, those who had the worst wrinkle scores were also those who had a higher prevalence of certain diseases—this when compared to smokers with the same smoking habits and the least wrinkles. Specifically, Daniell found that the smokers who had the least wrinkles were twice as likely not to have a history of heart attacks, strokes, or both. Even though these men smoked the same number of cigarettes for the same length of time, and even though they were the same age and gender, those with the greatest wrinkling had double the risk of these potentially fatal events.
Around the same time, aging expert Alex Comfort, PhD, of University College, London, was making a strong argument that microscopic examination of skin tissue could provide an excellent inferential test for overall human aging. Well known for establishing the first battery of clinical tests to estimate the human aging rate, Comfort relied heavily upon skin markers in the process. Specifically he used skin elasticity, collagen contraction, and fibroblast growth as key aspects in making objective measurements of aging. A few years later, dermatological scientist Gary Grove, PhD, found that human volunteers who were perceived to be older looking actually had much slower rates of skin healing. The older-looking volunteers had a marked reduction in the capacity of the outer skin layers to reproduce.
To underscore how visual cues can translate into perception of age and actual human health, researchers from the Gerontology Research Center in Baltimore set up an interesting experiment. They asked medical doctors to guess a person’s age based on a quick visual assessment. The doctors had no knowledge of the patient’s medical background or personal data; they also had no specialized training in visual-cue assessment. The results of the perception-based age guess, involving mote than one thousand adults, were subsequently evaluated alongside known markers of chronic disease risk, including blood tests, neurological tests, and so on.
The results, published in the journal Social Science and Medicine (1982), showed that in follow-up, the participants who were rated as looking “older for their age” were much more likely to die at a faster rate from various causes. Indeed, the visual perception of looking older was also associated with results of blood tests and other objective testing known to be markers of risk for chronic disease. In the study, the authors pointed out that wrinkles would obviously have been one of the cues used in visual assessment.
A more specific and recent investigation into facial aging and health was conducted by Kaare Christensen, MD, PhD, and colleagues from the Danish Twin Registry. This was a really neat study; published in the journal Epidemiology (2004), it looked at about one hundred sets of older adult twins whose faces had been digitally photographed with neutral expressions. Third-party evaluators, twenty nurses in this case, used the photographs to guess the age of each individual twin. In the years following, the researchers found that, among the twins, the individual twin who had been assessed as older looking was more likely to die from various health-related causes in 73 percent of the cases.
Further analysis of the perceived age of the twins indicated that genetic influence is not even close to the whole story of the visible signs of aging. Actually, genetics were estimated to account for only about half of the end result in facial appearance. If genetics were the whole story, then these older twin pairs should have had identical facial aging. But they didn’t. So, the next time you are told that someone has great skin because of his or her genes, tell him or her it isn’t so simple.
Martalena Purba, PhD, and colleagues from Monash University in Australia examined wrinkling at skin sites with only limited sun exposure to determine if wrinkling might be used as a surrogate marker for overall health status. Close to five hundred older adults were assessed via measures of skin wrinkling, tests of mental well-being, and blood work for a hormone associated with health and vitality called dehydroepiandrosterone (DHEA), a hormone that drops in level during the aging process.
The researchers found that the greater the degree of skin wrinkling, the lower the scores of general health (for conditions such as diabetes, heart disease, and hypertension) and overall functional status. They also found that those with the lowest degree of wrinkling had the highest blood levels of DHEA. Remember, these findings were based on assessments of skin wrinkling at skin sites not usually exposed to significant UV rays!
Other investigative groups have linked facial wrinkling with lung disease, and more recently, facial wrinkles were shown to predict poor kidney function. In the study published in Nephrology (2008), Korean researchers found that facial wrinkling was associated with a reduced kidney-filtration rate. This link was independent of age and gender, and once again, the researchers controlled for the potential bias of smoking-associated wrinkles and kidney function. They also eliminated the influence of sun exposure, diabetes, and other wrinkle-inducing confounding factors.
The Korean group showed a major link among reduced kidney filtration, wrinkles, and body-wide oxidative stress. In this case, blood markers of oxidative stress were much higher in those who had facial wrinkles, and the connection was a linear one. Higher levels of oxidative stress markers in the blood were associated with higher risk of overall wrinkles and greater severity and depth of wrinkles. Once again, looking old was linked to internal problems—in this case, a decreased ability to filter out toxins from the human body.
In sum, these studies show us that visible signs of aging are a potential mirror of internal health, and should not be dismissed offhand as an issue for celebrities and the vain who succumb to the pressures of our pop culture-driven society. Health and vitality are truly reflected in our skin. The benefits of good-looking skin are many, not the least of which is a potentially extended life with greater quality.