Some women like scruff. Others prefer man buns. (We know, we don't get it either.)
Now we can add a new point of attraction: a ruddy, glowing complexion, courtesy of a diet rich in beta-carotene. Apparently, among men with light skin, a more red-yellow complexion signals good health—even if a guy isn't necessarily that healthy, according to new research from Oxford University Press USA.
To put some evidence behind the "signal of health" theory—the premise that the appearance of good health is more sexually preferable—researchers snapped photos of 43 heterosexual Caucasian men, all about 21 years old. All participants were given a checkup to test their level of oxidative stress, immune function, and semen quality as indicators of overall health.
Then, the researchers asked 23 of these strapping youg men to try a beta-carotene supplement, which contains the red and yellow plant pigments natural to fruits and vegetables. (The other 20 guys just went on placebo pills.) At the study's conclusion, participants were photographed and examined again. As researchers expected, the beta-carotene supplementation increased tones of yellow and red on the men's faces.
Next, 66 Caucasian female raters (about 33-years-old) were recruited online to rate the attractiveness of the men—before and after the beta-carotene or placebo. The men's faces were presented side by side on a computer screen.
Why only Caucasian men? Turns out beta-carotene only has a significant effect on the appearance of lightly pigmented skin; previous research exploring its influence on darker skin—the study participants hailed from three separate regions of Africa—found that red-yellow changes only show up on lighter skin (like the palms of a guy's hand) or highly pigmented skin with low sun exposure (like the inner arm). In other words: Even after extensive beta-carotene consumption, swarthier men didn't look that different.
The study, published in the journal Behavioral Ecology, revealed women were more attracted to men with yellow- and red-pigmented skin—even though the coloring didn't necessarily mean this batch was healthiest. In fact, the beta-carotene treatment didn't alter any health functions for the better. So, why the preference? Researchers believe that humans, like other animals, are more enticed by their colorful male counterparts. Women are allured by signs of good health; it's intrinsically related to their desire to reproduce and survive, researchers say.
"Carotenoids are known to be responsible for the striking mating displays in many animal species," lead study author Yong Zhi Foo said in a press release. "Our study is one of the first to causally demonstrate that carotenoids can affect attractiveness in humans as well. It also reaffirms the results of previous studies showing that what we eat can affect how we look."
Of course, read these study results with a critical eye—it's a small study, and rating attractiveness is a notoriously unscientific method—we can't argue with eating these 5 beta-carotene-rich foods. They'll help you fake a tan—and maybe up your odds for finding a mate.