November 19, 2013
Muscle Mass Causes Men To Have Larger Noses Than Women
[ Watch the Video: Why Do Most Men Have Bigger Noses Than Women? ]
redOrbit Staff & Wire Reports - Your Universe Online
The average male nose is approximately 10 percent larger than the typical female proboscis, and the difference is likely due to the different builds and energy demands of the two genders, according to new research appearing in the American Journal of Physical Anthropology.
The size-difference holds true in populations of European descent, and the reason is that males typically have more lean muscle mass. As a result, they typically need to provide higher blood oxygen levels for the growth and maintenance of muscle tissue, and larger noses allow for increased oxygen intake, according to the authors.
The difference in schnoz size between boys and girls typically first appears around age 11, at the start of puberty, the researchers added. It is at that point that men begin to grow an increasing amount of lean muscle mass, while women tend to grown more fat mass. In fact, the authors cite previous studies that have shown approximately 95 percent of the body weight put on by men during puberty is fat-free, versus 85 percent in women.
“This relationship has been discussed in the literature, but this is the first study to examine how the size of the nose relates to body size in males and females in a longitudinal study,” lead author Nathan Holton, an assistant professor in the University of Iowa Department of Orthodontics, explained in a statement Monday.
“We have shown that as body size increases in males and females during growth, males exhibit a disproportionate increase in nasal size,” he added. “This follows the same pattern as energetic variables such as oxygenate consumption, basal metabolic rate and daily energy requirements during growth.”
These findings also help to explain why the noses of modern humans are smaller than those of our ancestors, including the Neanderthals. The study authors believe that ancient human ancestors had more muscle mass than modern-day men and women, and those needed larger noses to maintain their physiques. Since today’s humans have less lean muscle mass, we can survive without the need for massive honkers.
“So, in humans, the nose can become small, because our bodies have smaller oxygen requirements than we see in archaic humans,” Holton explained, adding that the lungs and rib cages of modern humans are also smaller, further reinforcing the notion that our bodies require less oxygen than our ancestors. “This all tells us physiologically how modern humans have changed from their ancestors.”
He and his colleagues tracked the nose size and growth of 38 individuals of European origin, all of whom participated in the Iowa Facial Growth Study from the age of three through their mid-twenties. The investigators took both internal and external measurements for each subject at regular intervals. They reported that boys and girls typically had roughly the same nose size through puberty, when the differences became far more pronounced.
“Even if the body size is the same, males have larger noses, because more of the body is made up of that expensive tissue. And, it’s at puberty that these differences really take off,” Holton said, adding that the gender differences his team discovered would likely hold true in other races and cultures. Additional research would be required to confirm that, however.
Image 2 (below): Male noses grow disproportionately larger than female noses beginning at puberty, a University of Iowa study has found. The reason: Males need to breathe in more oxygen to feed muscle mass than females. Image courtesy of the College of Dentistry.