Eating an overall healthy diet is tied to a lower risk of hip fracture among women over age 50, a U.S. study suggests.
Researchers analyzed decades’ worth of dietary and health data for more than 100,000 U.S. men and women. They found that women who scored highest on the American Healthy Eating Index-2010 (AHEI) scale were about 13 percent less likely to experience a hip fracture than those whose diets over time scored lowest on that quality measure.
There was no clear association between diet and hip fracture risk among men, the authors report in Journal of the Academy of Nutrition and Dietetics.
“We often find differences between men and women when it comes to the effect of diet on osteoporosis and hip fractures,” said lead author Diane Feskanich of Brigham and Women’s Hospital and Harvard Medical School in Boston.
“Women have less bone to begin with and go through an early bone loss around menopause. Men lose bone more slowly and experience hip fractures – on average – at a later age. So, it is quite possible that diet may be more important in women for preserving bone,” she said in an email.
Past research has often focused on particular nutrients or certain foods when examining the effect of diet on osteoporosis and resulting hip fractures, Feskanich noted. In recent years, the emphasis has shifted towards examining eating patterns as a whole.
“This is important because we do not eat particular nutrients and foods in isolation,” she said. Thus, understanding the combination of nutrients and foods and how they interact may be more informative, she added, and may yield better advice on how people should eat, which may benefit not only bone health but many other conditions.
The researchers looked at data on 74,446 postmenopausal women participating in the Nurses’ Health Study between 1980 and 2012 and 36,602 men age 50 or older who took part in the Health Professionals Follow-up Study between 1986 and 2012. Both groups completed yearly health surveys plus questionnaires on diet every four years.
There were 2,143 hip fractures among the women and 603 among the men across the study period. (Fractures resulting from car crashes and other traumatic accidents were excluded from this calculation).
Feskanich and colleagues rated the study participants’ diets over time according to three well-regarded scales of diet quality: The AHEI, the Dietary Approach to Stop Hypertension (DASH) and The Alternative Mediterranean Diet Score. All three scales award points for fruits and vegetables, whole grains, low-fat dairy products and other healthy foods. Points are withheld or even deducted if a diet includes high levels of red and processed meats, sodium or sugar-laden beverages.
When they compared these diet-quality scores to the incidence of hip fractures over the years, the study team found a significant difference in risk between women who scored highest on the AHEI scale and those who scored lowest.
There was a similar overall pattern among women based on their DASH and Alternative Mediterranean diet scores, but once researchers adjusted for other factors like body mass and physical activity, the difference was too small to rule out the possibility it was due to chance. Among women younger than 75, however, there were statistically meaningful differences in fracture risk tied to the highest versus lowest scores on all three diet indices.
Among the study’s limitations, the small number of hip fractures in men might have reduced the researchers’ ability to identify associations between fractures and diet. In addition, all the study participants in the analysis were white, which may make the results less generalizable to people of other ethnicities, the authors acknowledge.
The study was not a controlled experiment designed to prove that diet quality influences hip fracture risk directly. The study team adjusted for many other lifestyle and health factors that might play a role, and they note that people with higher diet-quality scores tended to have lower body mass and higher leisure time physical activity.
“Vitamins and minerals including calcium, vitamin D and vitamin K are essential for maintaining bone hardness and structure throughout the lifespan,” said Priya Khorana, an independent nutrition consultant in New York City who wasn’t involved in the study.
“Sure, bone integrity declines and composition weakens as people age, but this rate of decline can be attenuated with proper diets that include these key nutrients – among other foods,” she said in an email.
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