Research shows that despite their teeth’s massive size, the "Nutcracker Man" may not have had a regular diet of hard foods like nuts and seeds or roots and tubers.” title=”(Melissa Lutz Blouin, University of Arkansas)”/>
FRIDAY, June 1 (HealthDay News) — The heads of white Americans have become larger, taller and narrower since the 19th century, a new study says.
The forensic anthropologists at the University of Tennessee, Knoxville, did not pinpoint a reason for the changing head shapes or know whether it is primarily due to evolution or lifestyle changes.
“The varieties of changes that have swept American life make determining an exact cause an endlessly complicated proposition,” Lee Jantz, coordinator of UT’s Forensic Anthropology Center, stated in a university news release.
[Read: How to Stay Healthy at Work.]
“It likely results from altered growth patterns because of better nutrition, lower infant and maternal mortality, less physical work and a breakdown of former ethnic barriers to marriage,” Jantz said. “Which of these is paramount we do not know.”
The team analyzed 1,500 skulls dating from the mid-1800s to the mid-1980s and found that the average height from the base to the top of the skull in men increased by eight millimeters (0.3 inches), while skull size grew by 200 cubic centimeters, a space equivalent to a tennis ball.
In women, skull height increased by seven millimeters and skull size increased by 180 cubic centimeters.
Overall, skull height has increased 6.8 percent since the late 1800s, compared with a 5.6 increase in body height and a 2 percent increase in femur (thigh bone) length. The researchers also noted that skull height has continued to change while the increase in body height has recently slowed or stopped.
The study also found evidence that Americans are maturing earlier. An opening in a certain bone structure of the skull used to close at about age 20, but is now fusing at age 14 in girls and age 16 in boys.
[Read: Moms' Antidepressants May Affect Babies' Head Size.]
This could be due to rising rates of childhood obesity, which may affect hormones in ways that modify timing of growth and maturation, the researchers suggested.
Jantz stated researchers have documented less dramatic shifts in skull shape in Europe.
The study was recently presented at the annual meeting of the American Association of Physical Anthropologists.
Data and conclusions presented at meetings should be considered preliminary until published in a peer-reviewed medical journal.
The American Medical Association provides a close-up look at the human skull.
Copyright © 2012 HealthDay. All rights reserved.
- Food Bullying
- Food Bullying
- Patients often seek general medical care from specialists
- Native American Ancestors Came From Asia In Three Migrations
- American Diet Fuelling Heart Disease And Diabetes Rates In Southeast Asia
- Residents willing to work when they’re sick
- AMA Supports Requiring Obesity Education for Kids
- AMA: Trust but Verify Genetically Modified Foods
- HIV Returns in ‘Cured’ American Patient, Sparks Debate
- American Association for Public Opinion Research Welcomes a Distinguished Panel of Experts on Non-Probability Sampling at the 67th Annual Conference, May 17–20 in Orlando
Submited at Saturday, June 2nd, 2012 at 6:00 am on Uncategorized by Gillan
Comment RSS 2.0 - leave a comment - trackback