Osteoporotic fractures constitute a major burden for health care systems in aging societies. Although considerable research1- 6 has examined whether intake of nutrients involved in bone metabolism, such as protein, calcium, or unsaturated fat, can prevent fracture events, the findings are not consistent. However, suboptimal single nutrient intake does not occur in isolation but rather reflects a poor-quality diet.7
Several descriptive epidemiologic studies8- 10 have shown that the incidence of osteoporosis and osteoporosis-related fractures varies across nations, with a tendency of lower rates in Mediterranean compared with northern European countries. These differences have been attributed to life-style factors, including specific dietary patterns. The traditional Mediterranean-style diet emphasizes the consumption of dietary components, such as plant foods, fish, nuts, and monounsaturated fat, which have been shown11,12 to impart beneficial effects on bone health. Adherence to a Mediterranean diet was previously operationalized by a dietary scoring system and modified to be applied to non-Mediterranean populations.13 This Mediterranean diet score has been associated with a decreased hip fracture risk, particularly among men,14 but overall evidence is inconclusive.15 Moreover, data are sparse as to whether other dietary scoring systems that characterize a high-quality diet preserve bone health.16 Comprehensive analyses investigating the association between various commonly recommended dietary quality indexes and fracture risk in the United States are warranted.
The primary aim of this study was to examine the association between adherence to a diet quality index constructed on the basis of dietary recommendations or existing healthy dietary patterns and bone outcomes (hip or total fractures) in a large population of postmenopausal women. Specifically, diet quality was assessed using the alternate Mediterranean Diet (aMED) score,13,17 the Healthy Eating Index 2010 (HEI-2010),18 the Alternate Healthy Eating Index 2010 (AHEI-2010),19,20 or the Dietary Approaches to Stop Hypertension (DASH) score.21 As a secondary aim, the associations between diet quality, bone mineral density (BMD), and lean body mass measurements were examined. Given prior epidemiologic data14,16 and the composition of the aMED index, we hypothesized that high aMED scoring would be associated with a lower fracture risk.