Plant-based diet intake over time appears beneficial in reducing hip fracture risk, finds study

According to an original investigation on Nutrition, Obesity, and Exercise published in JAMA Network Open, researchers concluded that adhering to a plant-based diet did not affect the risk of hip fracture among postmenopausal women in the US. However, women with a recent healthy plant-based diet had a 21% lower fracture risk. In contrast, the most recent intake of an unhealthy plant-based diet was associated with a 28% higher fracture risk.

Previous studies have linked vegetarian diets to lower bone mineral density and higher fracture risk but failed to differentiate between the quality of plant-based foods. This study investigated the relationship between the quality of plant-based diets (omnivorous and vegan options) and hip fracture risk in postmenopausal women from the Nurses' Health Study. The study analyzed data from 70,285 participants between 1984 and 2014, with analysis conducted in 2023.

Hip fractures were reported on biennial questionnaires, and diet was assessed every four years using a validated food frequency questionnaire. The healthy Plant-Based Diet Index (hPDI) and the unhealthy Plant-Based Diet Index (uPDI) were used to assess plant-based diet quality. Healthy plant foods received positive scores, while less healthy plant and animal foods received reversed scores. The quintile scores of 18 food groups were summed, resulting in a theoretical range of 18 to 90 for both indices. Cox proportional hazards regression was used.

Key findings of the study are:

· The study had 70 285 participants, and 2038 cases of hip fracture were ascertained during the study and for up to 30 years of follow-up.

· Neither the hPDI nor the uPDI for long-term diet adherence was associated with hip fracture risk.

· Examining recent intake for the highest vs lowest quintiles, the hPDI was associated with a 21% lower risk of hip fracture and the uPDI was associated with a 28% higher risk with HR of 0.79 and 1.28 respectively, large sample size and extended follow-up, repeated assessment of diet and lifestyles were the main strengths of the study.

They said long-term adherence to a plant-based diet was not associated with hip fracture risk.

Reference:

Sotos-Prieto M, Rodriguez-Artalejo F, Fung TT, et al. Plant-Based Diets and Risk of Hip Fracture in Postmenopausal Women. JAMA Netw Open. 2024;7(2):e241107. doi:10.1001/jamanetworkopen.2024.1107