The results of a recent study published in The Journal of Nutrition do not support the notion that diet composition is the main reason for lower bone mineral density among vegetarians.While vegetarian diets gain popularity due to concerns about environmental sustainability and health, evidence suggests that vegetarianism is associated with low bone mineral density. However, previous studies have not considered anthropometric measures such as body mass index and waist circumference as potential determinants of lower bone mineral density among vegetarians rather than suboptimal dietary composition associated with plant-based diets.
Researcher Nena Karavasiloglou (Epidemiology, Biostatistics and Prevention Institute, University of Zurich) and colleagues utilized population-based data collected between 2007 and 2010 from the National Health and Nutrition Examination Survey, known as NHANES. The NHANES is a nationwide survey conducted in the United States to assess health and nutritional status. Differences in bone mineral density between adult vegetarians and nonvegetarians were evaluated, and associations between bone mineral density and diet were determined using statistical models.
Study results confirmed previous observations of lower bone mineral density values among vegetarians than among nonvegetarians. However, when adjusting for body mass index and waist circumference, differences in mean bone mineral density values became marginal and were no longer statistically significant.
This suggests that differences in bone mineral density between vegetarians and nonvegetarians may largely depend on body mass index and waist circumference. Thus, lower rates of fractures among nonvegetarians may likely be associated with a higher body mass index. These findings do not support the notion that dietary composition is the main reason for lower bone mineral density among vegetarians.
A corresponding editorial by Sue Shapses (Rutgers University) states that the finding of lower body size in vegetarians could at least partially explain why there is not a greater risk for fracture in vegetarians compared with nonvegetarians despite having lower bone mineral density.
References Karavasiloglou N, Selinter E, Gojda J, Rohrmann S, Kuhn T. Differences in Bone Mineral Density between Adult Vegetarians and Nonvegetarians Become Marginal when Accounting for Differences in Anthropometric Factors. The Journal of Nutrition. DOI: https://doi.org/10.1093/jn/nxaa018.
Shapses SA. Do We Need to Be Concerned about Bone Mineral Density in Vegetarians and Vegans? The Journal of Nutrition, DOI: https://doi.org/10.1093/jn/nxaa095.
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