If you are a middle-aged African-American or Asian woman, your social class may play a significant role in how likely you are to suffer bone fractures, a new UCLA-led study suggests. Higher social class linked to fewer bone fractures among non-white women, says the University of California - Los Angeles Health Sciences study, "Socioeconomic status in relation to incident fracture risk in the Study of Women’s Health Across the Nation," published online in the April 2014 issue the journal Osteoporosis International.
The study is unique in that it followed Asian, African-American and white women for a period of nine years during mid-life; most previous studies on socioeconomic status and osteoporosis risk had focused solely on older white women and often had not collected information on fractures over time.
The new findings help shed light on the importance of social class — and particularly education levels — in the fracture risk of mid-life women from different racial and ethnic groups, the researchers said.
Osteoporosis is a public health concern for a wide variety of individuals. About half of post-menopausal women and 20 percent of older men will suffer an osteoporosis-linked fracture, said the study's lead author, Dr. Carolyn Crandall, a professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA.
"The traditional paradigm of assessing fracture risk does not include consideration of socioeconomic factors, such as education and income," she said, according to the April 4, 2014 news release, Higher social class linked to fewer bone fractures among non-white women. "Examining the associations of socioeconomic status with fracture risk could help the targeting of individuals at risk of future fracture and inform the development of preventive strategies."
The researchers used data on 2,167 pre-menopausal women from the Study of Women's Health Across the Nation (SWAN) bone study
The women, who were between the ages of 42 and 52 when the study began, included 592 African-Americans, 1,093 Caucasians, 223 Chinese and 259 Japanese. At baseline, they had provided complete information on their income, education, osteoporosis risk factors and fracture occurrences. Each year for nine years, they reported on whether they had experienced any fractures since the last annual study visit.
The researchers found that among the non-white women in the study, a higher education level was associated with decreased fracture incidence. Those with at least some postgraduate education had an 87 percent lower non-traumatic fracture rate than those with no more than a high school education. In addition, each additional year of education was associated with 16 percent lower odds of experiencing a non-traumatic fracture.
The associations between higher education level and decreased fracture risk persisted even after accounting for income. Education was not associated with fracture risk among white women
"Interestingly, neither income level nor difficulty paying for basics was associated with fracture risk," Crandall said, according to the news release. "This may seem surprising, but previous studies had suggested that links between education and fracture risk may be more pronounced than links between income and fracture risk. This is probably because education reflects socioeconomic status both in childhood and young adulthood, whereas income and financial hardship only reflects current socioeconomic status. It suggests that socioeconomic status over the entire life course is more relevant than current socioeconomic status to bone health."
So why the link between education and lower osteoporosis risk among non-white women but not in white women? The authors speculate that minority-race women with less education encounter more life stresses than less educated white women; the stresses faced by less educated white women may not impact their bone strength enough to affect their fracture risk in mid-life.
This study does not establish a cause-effect relationship between low education and high fracture risk, but adds to the growing evidence of health disparities in our society
The study may also be limited by the fact that some fractures may not have been reported to the study investigators. The findings, however, still "highlight the need to elucidate the biological and behavioral mechanisms underlying the possible protective effects of higher educational level on osteoporotic fracture incidence so that we can better target individuals at risk of future fracture and design appropriate preventive strategies," the researchers conclude. You also may wish to check out the abstract of another study, "Celiac disease and risk of fracture in adults—a review."
Crandall received support from UCLA's Jonsson Comprehensive Cancer Center. SWAN has grant support from the National Institutes of Health, the U.S. Department of Health and Human Services (through the National Institute on Aging), the National Institute of Nursing Research, and the NIH Office of Research on Women's Health (grants NR004061, AG012505, AG012535, AG012531, AG012539, AG012546, AG012553, AG012554, AG012495). Study co-authors included Weijuan Han, Gail A. Greendale, Teresa Seeman and Arun S. Karlamangla of UCLA; Ping Tepper and Rebecca Thurston of the University of Pittsburgh; and Carrie Karvonen-Gutierrez of the University of Michigan.
Does a highly-processed junk food diet cause some types of fatigue, a sedentary lifestyle, and a lack of motivation?
Does a junk food diet make you lazy? A new study, "Food quality and motivation: A refined low-fat diet induces obesity and impairs performance on a progressive ratio schedule of instrumental lever pressing in rats," currently is published online in the journal Physiology and Behavior. Researchers looked at the relationship between health and lifestyle (diet and exercise) and the relationship between a junk food diet and cognitive impairments it may induce. The research also is scheduled for publication in the April 10, 2014 print edition of the journal Physiology and Behavior.
A new University of California - Los Angeles (UCLA) psychology study offers answer to why people on junk food diets feel so fatigued and sedentary. Do you feel that there's nowhere to hide from junk food, that it's all around you night and day? That UCLA psychology study provides evidence that being overweight makes people tired and sedentary — not the other way around, according to the April 4, 2014 news release, "Does a junk food diet make you lazy? UCLA psychology study offers answer."
Diet quality, not fat, is a cause of obesity and cognitive impairment, the researchers found
Life scientists led by UCLA's Aaron Blaisdell placed 32 female rats on one of two diets for six months. The first, a standard rat's diet, consisted of relatively unprocessed foods like ground corn and fish meal. The ingredients in the second were highly processed, of lower quality and included substantially more sugar — a proxy for a junk food diet. The study revealed that high fat diets (HFDs) cause obesity and cognitive impairment in rodents. High fat diets also are highly refined obscuring the causal factors in their effects.
Researchers fed rats a refined or unrefined low-fat diet (LFD). The results of the refined low-fat diet induced significant weight gain and motivational impairment. The scientists concluded in the study that therefore, diet quality, not fat, is a cause of obesity and cognitive impairment.
After just three months, the researchers observed a significant difference in the amount of weight the rats had gained, with the 16 on the junk food diet having become noticeably fatter
"One diet led to obesity, the other didn't," said Blaisdell, according to the news release. Blaisdell is a professor of psychology in the UCLA College of Letters and Science and a member of UCLA's Brain Research Institute. The experiments the researchers performed, Blaisdell said in the news release, also suggest that fatigue may result from a junk food diet.
As part of the study, the rats were given a task in which they were required to press a lever to receive a food or water reward. The rats on the junk food diet demonstrated impaired performance, taking substantially longer breaks than the lean rats before returning to the task. In a 30-minute session, the overweight rats took breaks that were nearly twice as long as the lean ones.
After six months, the rats' diets were switched, and the overweight rats were given the more nutritious diet for nine days. This change, however, didn't help reduce their weight or improve their lever responses.
The reverse was also true: Placing the lean rats on the junk food diet for nine days didn't increase their weight noticeably or result in any reduction in their motivation on the lever task. These findings suggest that a pattern of consuming junk food, not just the occasional binge, is responsible for obesity and cognitive impairments, Blaisdell said, according to the news release. "There's no quick fix," he noted.
What are the implications for humans? Do people who are overweight become less healthy or do less healthy people become overweight?
"Overweight people often get stigmatized as lazy and lacking discipline," Blaisdell said in the news release. "We interpret our results as suggesting that the idea commonly portrayed in the media that people become fat because they are lazy is wrong. Our data suggest that diet-induced obesity is a cause, rather than an effect, of laziness. Either the highly processed diet causes fatigue or the diet causes obesity, which causes fatigue."
Blaisdell believes the findings are very likely to apply to humans, whose physiological systems are similar to rats'. Junk food diets make humans — and rats — hungrier, he said in the news release. In addition, the researchers found that the rats on the junk food diet grew large numbers of tumors throughout their bodies by the end of the study. Those on the more nutritious diet had fewer and small tumors that were not as widespread.
Blaisdell, 45, changed his diet more than five years ago to eat "what our human ancestors ate." He avoids processed food, bread, pasta, grains and food with added sugar
He eats meats, seafood, eggs, vegetables and fruits, and he has seen dramatic improvements in his health, both physically and mentally. "I've noticed a big improvement in my cognition," he said, according to the news release. "I'm full of energy throughout the day, and my thoughts are clear and focused." An expert in animal cognition, Blaisdell conducts research that addresses the relationship between health and lifestyle (diet and exercise) and the relationship between a junk food diet and cognitive impairments it may induce.
"We are living in an environment with sedentary lifestyles, poor-quality diet and highly processed foods that is very different from the one we are adapted to through human evolution," he said, according to the news release. "It is that difference that leads to many of the chronic diseases that we see today, such as obesity and diabetes."
Co-authors of the research are Yan Lam Matthew Lau, Ekatherina Telminova and Boyang Fan, UCLA undergraduate students in Blaisdell's laboratory; Hwee Cheei Lim, the manger of Blaisdell's lab; Cynthia D. Fast, a UCLA graduate student in the lab; Dennis Garlick, a postdoctoral scholar in the lab; and David Pendergrass, a biology professor at the University of Kansas. The research was funded by the National Science Foundation and by entrepreneur Cameron Smith. Also you may wish to check out the abstract of another study, "The proper time for antioxidant consumption." Or see, "Dietary restriction reverses obesity-induced anhedonia."