Men's Bigger Noses Linked to Greater Oxygen Demand by Muscle Mass

Men of European decent have a nose that's 10 percent larger on average than their female counterparts, according to a new study that claims to be the first longitudinal analysis of nose size and how it relates to men and women.

While noses come in a variety of shapes and sizes, there is an overwhelming trend for men to have a larger nose than women; the size difference is associated with the greater lean muscle mass possessed by men, which requires more oxygen for muscle tissue growth and maintenance. Larger noses mean more oxygen can be inhaled and delivered to the muscles, the research suggests.

Differences in nose size between males and females usually begins to show around age 11 when puberty starts and males start to develop more lean muscle mass and females grow more fat mass. Previous studies have indicated that during puberty, about 95 percent of weight gain in males comes from fat-free mass, compared to 85 percent in females.

"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," said Nathan Holton, assistant professor in the University of Iowa College of Dentistry and lead author of the research. "We have shown that as body size increases in males and females during growth, males exhibit a disproportionate increase in nasal size. This follows the same pattern as energetic variables such as oxygenate consumption, basal metabolic rate and daily energy requirements during growth."

Holton said this grown pattern can also explain why our noses are smaller than our Neanderthal ancestors, who had more muscle mass, thus requiring a larger nose to maintain the muscle. Modern humans have less muscle mass than our ancestors, meaning we can get by with smaller noses.

"So, in humans, the nose can become small, because our bodies have smaller oxygen requirements than we see in archaic humans," Holton said, adding that the rib cages and lungs are also smaller in modern humans, which supports the idea that we don't need as much oxygen to feed our frames as our ancestors. "This all tells us physiologically how modern humans have changed from their ancestors."

Holton and his colleagues' work is published in the American Journal of Physical Anthropology.