Abstract. Bone mineral density (BMD) and fracture rates vary among women of differing ethnicities. Most reports suggest that BMD is highest in African-Americans, lowest in Asians, and intermediate in Caucasians, yet Asians have lower fracture rates than Caucasians.
Individuals of African descent have higher bone density and fewer fractures than Caucasians, whereas Asians have lower fracture rates despite lower bone density.
Chinese people have lower average bone mineral density than most other racial groups, but Chinese women have lower rates of spine fractures than white women and much lower rates of hip fractures than white women.
Data from the Study of Osteoporotic Fractures (SOF) and the Baltimore Men's Osteoporosis Study (MOST) show that, in both sexes, blacks have higher adjusted bone mineral density than whites and a slower age-adjusted annual rate of decline in bone mineral density.
To maintain strength, the width of the bone has to increase more than its length, which is why tall bones are disproportionately bigger, Heymsfield explained.
Manson, M.D. answers your health questions. Q: Can someone really be "big-boned"? A: Yes—but most people aren't. People like to say, "I'm not overweight; I'm just big-boned!" to justify a higher number on the scale, but in reality, less than 20 percent of women actually have larger-than-average body frames.
Excess weight is either the result of excess fat or excess muscle, not excess bone or big bones. So, the notion of being big-boned is a big myth…
We have earlier demonstrated that Polynesians have a higher bone mineral density (BMD) than age- and weight-matched Europeans in New Zealand (Cundy et al J Bone Miner Res. 1995; Reid et al Br Med J 1986).
Most studies report ethnic differences in areal bone mineral density (aBMD), which do not consistently parallel ethnic patterns in fracture rates. Variations in body size and composition are likely to contribute to reported differences.
However, many reports now describe race and ethnic differences in BMI–adiposity relationships (4–7). That is, for any value of BMI, there are differences in percentage body fat (% fat) between subjects of the same sex across race and ethnic groups.
Bone mineral density (BMD) and fracture rates vary among women of differing ethnicities. Most reports suggest that BMD is highest in African-Americans, lowest in Asians, and intermediate in Caucasians, yet Asians have lower fracture rates than Caucasians.
Highest density bone is located either at subchondral end plate of sacral vertebral body or in contralateral ilium and provides the strongest fixation.
Boys and girls who are too thin will definitely have lower bone density. If they are too heavy, sometimes the bone density will be high. But if kids are fat because they don't get any exercise, the bone density might be low and they might break their wrist more easily. Some teenage girls have anorexia.
Soccer and gymnastics sport groups were found to have the highest bone density in most body segments, and both sports were among the groups with the lowest fat mass.
Obese adults have higher BMD, thicker and denser cortices, and higher trabecular number than normal adults. Greater differences between obese and normal adults in the older group suggest that obesity may protect against age-related bone loss and may increase peak bone mass.
Past studies suggest that genetic differences may account for more than half the variance in bone mineral density between people. Previous genome-wide association studies identified 24 genetic regions that influence bone mineral density.
The completion of the Human Genome Project in 2003 confirmed humans are 99.9% identical at the DNA level and there is no genetic basis for race.
Bones containing more minerals are denser, so they tend to be stronger and less likely to break. Bones can become less dense as we age or if we develop certain medical conditions.
Analyzable DNA often persists in bones and teeth much longer than in the soft tissues of the body, because the rigid structure of bones and teeth provide some protection against DNA degradation.
“This high prevalence of obesity among Samoans is a relatively recent phenomenon,” Arslanian notes. It appears to be “heavily influenced by globalization” and “the shift from subsistence agriculture to excess consumption of high calorie, processed foods and sedentary lifestyles.”
Some scientists believe Tonga's problem is partly down to genetics - that Pacific islanders in the past had to survive long periods without food so their bodies are programmed to cling on to fats.
Nutrient transmission (change in diet) is the primary cause of the obesity epidemic in the Pacific Islands, with a high amount of imported foods high in salt and fat content grow.
Genes control about 60% to 75% of the variance of peak bone mass/density and a much smaller proportion of the variance in rate of loss.
Only about 15 percent of people do have a larger than average frame, and about the same have a smaller than average skeleton.
From the outside everyone's bones look the same, it's only when you get inside them that the differences can be seen. Bone density (the thickness of our bones) relies on a good diet, sunlight and physical activity to keep them strong.