Vegan diets may pose higher risk of bone fractures, study finds

24 Nov 2020 --- Vegans, vegetarians and pescatarians are up to 43 percent more likely to suffer bone fractures compared with those who eat meat and dairy, according to a study published in BMC Medicine. 

Researchers analyzed data from almost 55,000 people in the UK whose eating habits were assessed over a 14 year period. Participants were simultaneously tracked for the occurrence of bone fractures over a longer period (18 years on average) until 2016.

After the data was adjusted to account for socioeconomic factors, lifestyle confounders and body mass index (BMI), non-meat eaters were found to have significantly higher rates of site-specific bone fractures. 

The team of researchers are from the Universities of Oxford and Bristol and analyzed data collected in the EPIC-Oxford study, a prospective cohort study originally of 65,000 men and women in the UK designed initially to investigate connections between nutrition and cancer. 

Brittle bones in non-meat eaters
In particular, vegans proved to suffer hip fractures at 2.3 times the rate of meat-eaters. 

Fractures to hips and legs were higher in fish eaters and vegetarians as well, though certain other areas, such as wrists and ankles, produced no significant difference between dietary groups. 

Differences were partly reduced once BMI, dietary calcium and dietary protein intakes had been accounted for. 

During the study, 3,941 fractures occurred in total, including 566 arm, 889 wrist, 945 hip, 366 leg, 520 ankle and 467 fractures at other main sites, defined as the clavicle, ribs and vertebrae. Twelve of the reported cases had occurred upon death. 

“Previous studies have shown that low BMI is associated with a higher risk of hip fractures, and low intakes of calcium and protein have both been linked to poorer bone health,” says Dr. Tammy Tong, a nutritional epidemiologist at the Nuffield department of population health, University of Oxford. 

“This study showed that vegans, who on average had lower BMI as well as lower intakes of calcium and protein than meat-eaters, had higher risks of fractures at several sites.”

Researchers found vegan diets may more than double the chances of bone fractures.

Veganism retains benefits
Tong emphasizes, however, that the results must be used proportionally and in context, given the proven benefits of non-meat diets.

“Well-balanced and predominantly plant-based diets can result in improved nutrient levels and have been linked to lower risks of diseases, including heart disease and diabetes.” 

“Individuals should take into account the benefits and risks of their diet, and ensure that they have adequate levels of calcium and protein and also maintain a healthy BMI, that is, neither under nor overweight.”

Industry innovations in calcium supplements could aid veganism’s benefits. Earlier this year, mineral ingredients group Omya released an infant formula to strengthen calcium levels, and vitamins D3 and K2 have been shown to balance calcium and aid its absorption in infants following regular diets. 

“Potential errors” and study limitations
The authors of the study were careful to highlight some significant gaps in the study’s breadth. 

They were unable to differentiate between fractures, resulting from poor bone health and those caused by accidents – such as falling from heights. 

This was because the causes were not available in the data, the researchers note. 

Moreover, no data was available on the uses of calcium supplements between different dietary groups and measurements of nutrients such as calcium and proteins were subject to potential measurement errors. 

The study also analyzed bone health in predominantly white European participants, although the study authors stress that bone health varies between ethnic groups. A 2017 study, for example, showed that bone mineral density differs by race and sex. 

The researchers are calling for further studies to help close these gaps.

Industry opportunities 
Last year NutritionInsight reported that industry experts are highlighting the space for NPD as concern over bone and mobility health is reaching younger markets. 

Ingredients such as curcumin and omega 3 were emphasized as key for industry players as a younger demographic of sporty, physically active individuals seek ways to protect their heavily-used joints.

By Louis Gore-Langton