Vegetarian diet linked to higher hip fracture risk: researchers flag reformulation potential

12 Aug 2022 --- Women following a vegetarian diet have a 33% higher risk of hip fracture compared to regular meat eaters, a UK study has revealed. The findings have prompted a call for better communication from policymakers on the impact of following certain diets, as well as the importance of food reformulation.

The research observed 26,318 women over the course of 20 years. At the time they were recruited into the cohort study, the women ranged in age from 35 to 69 years. A total of 822 hip fracture cases were confirmed with hospital records, representing 3% of the sample population.

After adjusting for factors such as smoking and age, vegetarians were the only diet group with an elevated risk of hip fracture. 

“We know there are many benefits to eating a plant-based diet, including for health and the environment. However, we need to be aware to optimize the balance of nutrients in our diets,” professor Janet Cade, part of the Nutritional Epidemiology Group, School of Food Science and Nutrition at Leeds University (UK), tells NutritionInsight.

“Policymakers need to communicate the possible risks of choosing a particular dietary pattern along with the benefits. Clearly, it is possible to eat a healthy vegetarian diet as it is a healthy diet. People need information to make a sensible choice.”

Eyeing the nutritional impact
The scientists stress the need for more research into the exact causes of why vegetarians were at a greater risk of hip fracture. Nonetheless, the findings, published in BMC Medicine could play a role in the food industry, through reformulation.

General recommendations are to consume around 20 g of protein at each meal, Cade explains. Some vegetarian diets may lack enough nutrients for good bone and muscle health, increasing the chance of a fracture.

“The food industry should consider the balance and quality of nutrients provided in plant-based products to ensure adequate levels of high-quality protein and calcium. Calcium and protein from plants are less well absorbed than those from animal sources. If food products are aiming to replace meat-based meals, these should ensure appropriate levels of protein,” adds Cade. 

Consumers eating vegetarian diets may be at higher risk of missing out on certain nutrients.Fortification and supplements
Whilst most nutrients can be obtained through the right choice of foods, vitamin B12, in particular for those not eating any animal products, is a concern. This needs to be consumed by either choosing fortified foods or supplements.

“Vegetables as a side dish would not need supplementing with protein, however, a vegetarian main dish should ensure adequate levels of protein to enable reference intakes to be reached. Plant-based products replacing dairy items should be fortified with calcium,” says Cade.

“Other nutrients to consider in this process would be vitamin B12, vitamin D, omega 3 fatty acids, phosphorus and zinc – all of these may be limited in vegetarian and plant-based diets.”

While most nutrients can be obtained through the right choice of foods, vitamin B12, in particular, is a concern for those not eating any animal products. This needs to be consumed through either choosing fortified foods or supplements, specifies Cade. 

Global health issues
Vegetarian diets have gained popularity in recent years, with a 2021 YouGov survey putting the size of the UK vegetarian population at roughly 5-7%. There is also a worldwide call for reducing the consumption of animal products in an effort to tackle climate change. 

Understanding hip fracture risk in vegetarians is therefore becoming increasingly important to public health, the researchers note.

“Hip fracture is a global health issue with high economic costs that causes loss of independence, reduces quality of life, and increases risk of other health issues,” says the study’s lead author and doctoral researcher at the School of Food Science and Nutrition at Leeds, James Webster. 

“Plant-based diets have been linked with poor bone health, but there has been a lack of evidence on the links to hip fracture risk,” he remarks. “This study is an important step in understanding the potential risk plant-based diets could present over the long-term and what can be done to mitigate those risks.”  

“Our study highlights potential concerns regarding the risk of hip fracture in women who have a vegetarian diet. 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.” 

By Andria Kades