Effects of Dietary Pattern on Average Cortical Bone Density and Estimated Thickness of the Proximal Ulna

Abstract

There is an established relationship between diet and phenotype in various human body systems. Vegetarian diets may contain lower quantities of calcium and protein compared to other diets, causing speculation that this dietary pattern may contribute to lower bone mineral density (BMD) or osteoporosis. Nutritional intake is a major element in a person’s overall Bone Mineral Density (BMD), but little is known about how the upper extremity responds to changes in dietary pattern. There is also conflicting evidence for the effects of a vegetarian diet on bone, with some studies suggesting that lower quantities of calcium and protein compared to other diets contributes to lower bone mineral density (BMD), while others find that the lower acidic load found in the vegetarian diet combined with a higher intake of potassium have a calcium‐sparing effect with positive effects on bone health. This study tests how vegetarian and convenience diets affect Cortical Bone Thickness (CBT) and Average Cortical Density (ACD) of the olecranon process in humans, a site of fracture in the upper limb.Computed tomography (CT) scans with varying dietary pattern were obtained from the New Mexico Decedent Image Database and segmented in 3D Slicer. Cortical thickness was measured by calculating the difference between periosteal and endosteal section contours. Density was approximated by comparing the average radiodensity after applying a threshold of 500 HU to isolate cortical bone. MANOVA and post‐hoc ANOVA testing were conducted in R Studio to test differences between dietary groups. There was a statistically significant effect of bone length (p = 0.001) and diet (p = 0.014) on both proximal ulnar bone properties measured (approximated cortical thickness and density). Post‐hoc testing found that only bone length had a significant effect on cortical thickness (p = 0.003) while diet, but not bone length or sex, had a significant effect on average cortical density (p = 0.008).These results provide evidence of detrimental effects of a convenience diet on bone density, and possible evidence for beneficial effects of a vegetarian diet. Convenience foods are high in saturated fats, sodium, and refined sugars, which have been shown to have negative effects on bone mass and bone microarchitecture in rodents. Our results suggest that similar effects may be seen in the cortical bone of humans, providing additional evidence for the negative effects of convenience food on health. Previous studies have found that nutritional acidic load, which may be lowered by a vegetarian diet, is positively correlated with fracture risk and negatively correlated with BMD. Our results support these findings and add to the growing evidence for the benefits of a vegetarian diet.