Risk for hip fracture elevated in women who are vegetarian vs. meat-eaters

Women who are vegetarian had a greater risk for hip fracture compared with those who ate five or more servings of meat per week, findings in BMC Medicine showed.

“Our study highlights potential concerns regarding risk of hip fracture in women who have a vegetarian diet,” James Webster, MSc, a postgraduate researcher in the University of Leeds Nutritional Epidemiology Group in England, said in a press release. “However, it is not warning people to abandon vegetarian diets. As with any diet, it is important to understand personal circumstances and what nutrients are needed for a balanced healthy lifestyle.”

Webster and colleagues identified 26,318 participants (aged 35 to 69 years) in the U.K. Women’s Cohort Study (UKWCS) — a questionnaire-based study conducted via mail by the World Cancer Research Fund between 1995 and 1998 in England, Scotland and Wales — who completed an additional in-depth questionnaire on diet, lifestyle, demographics and anthropometric information.

The researchers categorized participants as:

• regular meat-eaters if they ate at least five servings of meat per week;
• occasional meat-eaters if they ate fewer than five servings of meat per week;
• pescatarians if they ate fish but not meat; and
• vegetarians if they did not eat meat or fish.

To assess incidences of hip fracture, the researchers linked the UKWCS data with participants’ hospital episode statistics through March 31, 2019.

Overall, there were 822 incidences of hip fracture in 556,331 person-years. Compared with women who were regular meat-eaters, those who were vegetarian had a significantly greater risk for hip fracture (adjusted HR = 1.33; 95% CI, 1.03-1.71). Women classified as occasional meat-eaters and pescatarians did not have a greater risk for hip fracture compared with those who were regular meat-eaters.

Subgroup analyses revealed that having a BMI less than 23.5 kg/m² was associated with a 46% higher risk for hip fracture compared with having a BMI of at least 23.5 kg/m². However, BMI did not modify the effect diet had on hip fracture risk.

Age, physical activity, nutritional supplementation, socioeconomic status and smoking status also did not affect the risk for hip fracture within any diet group, “implying the potential importance of other unaccounted factors,” Webster and colleagues wrote.

The researchers cautioned that participants were, on average, aged younger than 83 years, which is the average age for hip fracture in women. They also could not determine whether fractures were caused by trauma or bone fragility.

“Further research is needed to confirm this in other populations, such as men and non-European populations, and to identify the factors responsible for the observed risk difference,” Webster and colleagues wrote. “In particular, further research exploring the roles of BMI and nutrients abundant in animal-sourced foods is recommended so that public health interventions and policy guidelines aiming to reduce hip fracture risk in vegetarians through dietary change or weight management can be formed.”

References:

• Vegetarian women are at a higher risk of hip fracture. https://www.eurekalert.org/news-releases/961157. Published Aug. 10, 2022. Accessed Aug. 16, 2022.
• Webster J, et al. BMC Med. 2022;doi:10.1186/s12916-022-02468-0.