Nutrition Hotline
Vegan Diets and Risk of Hip Fracture
By Reed Mangels, PhD, RD
QUESTION: I've seen headlines about vegan diets and hip fracture risk. Should I be concerned?
RS, via email
ANSWER: A number of recent large studies from the United States, Canada, and the United Kingdom have examined fracture risk in vegans:
- UK Women's Cohort Study—vegan women had a higher risk of hip fractures than did meat eaters.1
- UK EPIC-Oxford Study—vegans had more than twice the risk of hip fractures compared to meat eaters.2
- US and Canada Adventist Health Study-2—vegan women, but not vegan men, had a markedly higher risk of hip fractures than did nonvegetarians.3
- UK Biobank Study—vegetarian, including vegan, men and women had a higher risk of hip fractures than did meat eaters.4
There are several possible explanations for these results. The lower average body mass index (BMI) in vegans may partially explain their higher risk of hip fracture.1,4 A lower BMI has been associated with less dense bones because bones are strengthened by weight-bearing exercise. If a person weighs more, their bones bear more weight. Additionally, having a bit more body fat may cushion the hips when a fall occurs.
One study found that higher intakes of calcium and vitamin D, from a combination of food and supplements, were associated with a lower risk of hip fractures.3 Another study found that differences in dietary protein and calcium intake did not completely explain group differences in hip fracture risk.2 This study did not measure vitamin D intake. The effect of different intakes of other nutrients, such as vitamin B12 that can affect bone health, was not reported in these studies. In many cases, we also don't know about the quality of the subjects' diets or whether they got adequate calcium and vitamin D when they were adolescents, a key time for bone growth.
A helpful perspective is offered by the researchers from the UK Biobank study who point out that, while the vegetarians (this group includes vegans) had a 50% higher risk of hip fractures than did meat eaters, this represents only about 3.2 more cases of hip fractures per 1,000 people over 10 years. This modestly higher absolute difference in risk should be weighed against vegetarians' lower risk of cancer and cardiovascular disease.4
The results of these studies are a reminder that vegans should follow general recommendations to promote healthy bones, including getting adequate calcium, vitamin D, protein, and vitamin B12; getting regular weight-bearing exercise; and striving to have BMIs within the "healthy weight" range as opposed to the "underweight" range.
REFERENCES:
1 BMC Med. 2022;20:275.
2 BMC Med. 2020;18:353.
3 Am J Clin Nutr. 2021;114: 488-495.
4 BMC Med. 2023;21:278.
