Is there an increased fracture risk in vegetarians and vegans?

05.2023
Author Dr. J. Hower, Paediatrician from Germany

There is strong evidence that inadequate intake of certain micronutrients and macronutrients can affect bone health. It is unclear, however, whether a purely plant-based diet leads to poorer bone health.  The authors have conducted a review of current findings on this topic.

A purely plant-based diet is gaining increasing public interest as it can improve metabolic health.  Studies that examine vegetarians and vegans together show a lower bone mineral density (BMD) but not always an increased fracture risk compared to omnivores. However, vegans consistently have a higher risk of fracture, especially at the hip. The higher risk of fracture may be due to reduced intake of calcium and vitamin D, as well as the quantity and quality of proteins in the diet. Other nutrients (B vitamins, selenium, zinc, iron, iodine) or physiological factors (lower body mass index, microbiome, or endocrine profile) may also play a role, but have not yet been studied in detail.

Comment: Nutrition is an important modifiable factor influencing bone health. There is only limited prospective evidence on potential differences in fracture risk between vegetarians, vegans and non-vegetarians.  Fractures caused by low bone mineral density (BMD) affect health and well-being at any age. A general link between nutrition and bone health has already been demonstrated. In particular, the consumption of milk and dairy products seems to be associated with better bone density. With the increasing popularity of plant-based diets among adolescents, vegan diets in particular appear to be a risk factor for long-term bone development. This link is confirmed by Ogilvie’s latest study on increased fracture risk in vegetarians, but especially in vegans.  

References:
Ogilvie AR, McGuire BD et al. Fracture Risk in Vegetarians and Vegans: the Role of Diet and Metabolic Factors. Curr Osteoporos Rep. 2022 Dec;20(6): 442–452. doi: 10.1007/s11914-022-00754-7. Epub 2022 Sep 21.
Fabiani R, Naldini G et al. Dietary Patterns in Relation to Low Bone Mineral Density and Fracture Risk: A Systematic Review and Meta-Analysis. Adv Nutr. 2019 Mar 1;10(2): 219–236. doi: 10.1093/advances/nmy073.
Tong TYN, Appleby PN et al. Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study. BMC Med. 2020 Nov 23;18(1): 353. doi: 10.1186/s12916-020-01815-3.