Approved Research

Risk of hip fracture in meat-eaters, pescatarians, vegetarians, and vegans.

Lay summary

Hip fracture is a common serious injury in older adults that reduces mobility, independence, and quality of life, and can lead to premature death. Around 1.6 million cases occur globally per year, and continual increases in the number of older adults worldwide suggests that cases could reach 4.5 million by 2050. Diet can affect bone health and risk of hip fracture, with varying risks in adults on specific diets. There is some evidence that vegetarians and vegans may have poorer bone health and higher risks of fractures than meat-eaters, but evidence for hip fractures is limited, and underpinning mechanisms explaining risk differences are unclear.

The main aim of this research is to investigate risk of hip fracture in occasional meat-eaters, pescatarians, vegetarians, and vegans compared to regular meat-eaters. A secondary aim is to determine if risk of hip fracture in these diet groups depends on age, sex, body mass index, use of calcium and vitamin D supplements, and diet-gene interactions. Thirdly, we will explore the role of potential factors underpinning any risk differences, such as body weight, bone mineral density, and intake of nutrients that are mostly found in animal-sourced foods. The purpose of this study is to better understand hip fracture risk in vegetarian and vegan UK adults. The proposed project will use existing diet and lifestyle data from the UK Biobank and hospital records of hip fractures.

The number of vegetarians and vegans globally is rising; this will be the largest investigation of risk of hip fracture in men and women following vegetarian or vegan diets, with diet-gene interactions accounted for, and will inform nutritionists, policymakers, and health professionals on the adequacy of these diets in terms of hip fracture risk. We will also identify possible explanations for any observed risk differences that could be the subject of further research.