Women who are vegetarian are a third more likely to experience a hip fracture in later life than those who regularly eat meat, a new UK study has found.
Researchers at the University of Leeds analysed health and diet records from more than 26,000 women over a 22-year period.
The Leeds team say the reasons for the higher hip fracture risk among vegetarian women remain unclear, especially since previous studies have shown that diets featuring a higher intake of fruits and vegetables including foods high in vegetable protein have been associated with a reduced hip fracture risk in adults. However the findings of the new study do broadly concur with the two earlier studies looking specifically at this risk group.
The researchers say one possibility for the greater fracture risk in vegetarians is lower intake of nutrients important to bone health that are abundant in animal products. Previous studies have found lower dietary intakes of protein, calcium, vitamin D, and vitamin B12 in vegetarians, and have suggested protective associations of these nutrients with hip fracture risk. In the new study, vegetarians had lower dietary intakes of protein, vitamin D, and vitamin B12, but similar dietary calcium intakes to other diet groups.
“In the new study, vegetarians had lower dietary intakes of protein, vitamin D, and vitamin B12, but similar dietary calcium intakes to other diet groups”
The Leeds team also found that the average body mass index (BMI) among vegetarians was slightly lower than the average among the regular meat eaters. Previous research has shown a link between low BMI and a high risk of hip fracture.
Lower BMI can indicate people are underweight, which can mean poorer bone and muscle health, and higher risk of hip fracture. The researchers say further investigation is needed to determine if low BMI is the reason for the observed higher risk in vegetarians.
Lead study author James Webster, a doctoral researcher from the School of Food Science and Nutrition at Leeds, said: “Our study highlights potential concerns regarding risk of hip fracture in women who follow 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.
“Vegetarian diets can vary widely from person to person and can be healthy or unhealthy, just like diets that include animal products.
“However, it is concerning that vegetarian diets often have lower intakes of nutrients that are linked with bone and muscle health. These types of nutrients generally are more abundant in meat and other animal products than in plants, such as protein, calcium, and other micronutrients.
“Low intake of these nutrients can lead to lower bone mineral density and muscle mass, which can make you more susceptible to hip fracture risk. This makes it especially important for further research to better understand factors driving the increased risk in vegetarians, whether it be particular nutrient deficiencies or weight management, so that we can help people to make healthy choices.”