by Cristina Goyanes

Mirrors can tell us lots of things: whether that hangover from last night is showing in our faces, whether we've finally tamed that cowlick, whether our butts really do look big in those pants. But they can also give us a telling glimpse into what's going on below the surface.

Science suggests some physical traits may indicate clues about our health. Last week, for instance, American and German researchers published a study showing that tall men (6'3" and over) were 40 percent more likely to get an aggressive form of prostate cancer than men of average (5'7") height . This finding illustrated what researchers had long suspected: a report published in Cancer Epidemiology, Biomarkers & Prevention last year  found that men’s cancer risk increased by 6 percent for every additional 3.9-inch increase in height over the average, and that having longer legs increased the odds from 12 to 23 percent.

This finding had us thinking - what other seemingly innocent traits were connected to larger health issues?   We collected five examples of how your body can spill secrets about your future health:

Being Tall: Cancer

Men aren't the only ones at risk: a study from Dutch researchers showed that  women who were 5-feet, 9 inches or taller were also more likely to develop breast cancer.  Why this happens is still not understood, but it may have something to do with the production of a hormone, Insulin-Like Growth Factor-1. Rest assured: size doesn’t matter too much. Or at least not enough to lose sleep over this slightly elevated risk.

Redheads: More Dental Pain

A study from published in the Journal of the American Dental Association made news last month, showing that natural redheads carry a gene mutation that may affect their brain’s ability to process pain-blocking meds like Novocain. Scientists still don’t know what’s happening in the bodies of people who have this melanocortin-1 receptor gene variation, but lead study author Catherine Binkley, DDS hopes that taking a blood sample or swabbing a cheek will let doctors know which patients are prone to anxiety—carriers were twice as likely to skip dental visits—and may require stronger anesthesia.

Dark skinned individuals: May develop nasty smoking habit, eventual cancer.
People who have a dark complexion—thanks to genetics or tanning—are more likely to develop nicotine dependence, which, ultimately, may lead to tobacco-specific diseases, says a study published in Pharmacology, Biochemistry and Behavior.  Previous lab work had already established that nicotine binds to melanin, a tissue that determines the pigmentation of one’s skin. Building on that, Pennsylvania State University researchers discovered that when nicotine bonds to high concentrations of melanin, it metabolizes at a slower rate throughout the day opposed to the average two hours.

“Dark-skinned people smoke fewer cigarettes than their lighter-skinned counterparts because they are satiated longer,” says lead investigator Gary King. “However, we believe that some carcinogens are also binding and remaining in the body longer as well. This may help explain why African Americans have a higher incidence of smoking-related cancers,” he adds.

Men with asymmetrical faces: More likely to have dementia
Not even the best poker face can hide the fact that men with crooked grins may experience a blackout in brainpower one day. An article published in the journal Evolution and Human Behavior  discovered that the men who had asymmetrical faces—the left side didn’t mirror the right—were more likely to develop dementia than those with well-balanced mugs.

Using 216 photographs of men and women between the ages of 79 and 83, researchers measured 15 facial landmarks, including the corners of the eyes and mouth as well as the side of the nose and chin points. “Facial symmetry, just like body symmetry, is thought to be an indicator of developmental stability," says Lars Penke, the study author. "If one side grows smaller or larger than the other, this means that something has gone a little wrong, that the development was disrupted, for example by exposure to pathogens, toxins or radiation, by malnutrition or by genetic mutations."

Only men, not women, showed the connection between a lack of symmetry and senility. Why the gender discrepancy?  Perhaps it’s because women generally live longer and take better care of their bodies, says Penke who encourages everyone—male or female, droopy face or no—to  cultivate a healthy body in order to keep a sharp mind.

Long ring fingers: Great In bed,  at risk for osteoarthritis
How’s this for palm reading: If your ring finger is longer than your index finer you may be twice as likely to develop osteoarthritis, say British researchers. In the past, the index and ring finger ratio has been linked to good things: higher sperm count, athletic ability, and sexual prowess. But this article published in the journal Arthritis and Rheumatism is the first to find a connection between the digit ratio and hip and knee problems.
Researchers took radiographs of the knees, hips, and hands of more than 3,000 people, most of whom had a history of below the waist joint issues. What they discovered was that those whose index finger was shorter than their ring were at greater risk of knee osteoarthritis. This was especially true for women, who generally have equal sized second and fourth fingers. Why? Again, still a mystery. These studies are designed to find signifiers or common traits in those who have a disease, but aren't always able to speculate why those traits influence health.