{"id":16544,"date":"2020-11-27T11:00:47","date_gmt":"2020-11-27T16:00:47","guid":{"rendered":"https:\/\/www.vrg.org\/blog\/?p=16544"},"modified":"2020-11-24T10:43:14","modified_gmt":"2020-11-24T15:43:14","slug":"new-study-finds-increased-fracture-risk-in-non-meat-eaters","status":"publish","type":"post","link":"https:\/\/www.vrg.org\/blog\/2020\/11\/27\/new-study-finds-increased-fracture-risk-in-non-meat-eaters\/","title":{"rendered":"New Study Finds Increased Fracture Risk in Non-meat Eaters"},"content":{"rendered":"\n
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By Reed\nMangels, PhD, RD<\/p>\n\n\n\n

A recently\npublished study about fracture risk in non-meat eaters has received a lot of\nmedia attention. Here\u2019s what you need to know.<\/p>\n\n\n\n

What is the study?<\/strong><\/p>\n\n\n\n

The study is\nfrom the United Kingdom and was conducted by researchers at Oxford University\nand the University of Bristol. Study subjects were recruited between 1993 and\n2001 and were studied until 2016. About 55,000 men and women were included in\nthe study. At the start of the study, subjects were classified into 1 of 4\ndietary groups based on their responses to a questionnaire which asked\nquestions like \u201cDo you eat any meat?\u201d The groups were meat eaters, fish eaters\n(did not eat meat but ate fish), vegetarians (did not eat meat or fish, but ate\none or both of dairy or eggs), and vegans (participants who did not eat meat,\nfish, dairy, and eggs). At the start of the\nstudy there were 29,380 meat eaters, 8,037 fish eaters, 15,499 vegetarians, and 1,982\nvegans.  <\/p>\n\n\n\n

     Some subjects completed a similar\nfollow-up questionnaire in 2010. The majority of subjects had followed the same\ndiet for years before the start of the study. For example, 88% of fish eaters, vegetarians, and vegans had\nnot eaten meat for at least 5 years before recruitment, 85% of vegetarians and\nvegans had not eaten fish for at least 5 years before recruitment, and 82% of\nvegans had not eaten eggs or dairy for at least 3 years before recruitment. <\/p>\n\n\n\n

     During the follow-up period,\nthe occurrence of fractures was determined through use of the National Health\nService\u2019s records. The study\u2019s goal was to determine if there were differences\nin fracture risks between vegetarians, vegans, and non-vegetarians.<\/p>\n\n\n\n

What did it find?<\/strong><\/p>\n\n\n\n

Over the follow-up\nperiod which averaged 17.6 years, there were 3,491 fractures \u2013 566 arm\nfractures, 889 wrist fractures, 945 hip fractures, 366 leg fractures, 520 ankle\nfractures, and 467 other fractures. The researchers were not able to determine\nhow many fractures were due to trauma like auto accidents and how many were due\nto osteoporosis (weak bones). <\/p>\n\n\n\n

     Compared with meat eaters, vegetarians and\nvegans had a higher risk of total fractures and hip fractures and vegans had a\nhigher risk of leg fractures and of vertebral fractures. Vegetarians had a 25%\nhigher risk of hip fractures than did meat eaters while vegans had more than\ntwice the risk. No significant differences were seen between the groups in the\nrisk of wrist or ankle fractures or the risk of arm fractures after controlling\nfor body mass index (BMI). <\/p>\n\n\n\n

     Differences in BMI between the groups\naccount for some of the differences in fracture risk. Vegans tend to have a\nlower BMI on average. A lower BMI has been associated with less dense bones\nbecause bones are strengthened by weight-bearing exercise. If a person weighs\nmore, their bones do more weight-bearing. Additionally, some studies have found\nincreased risk of hip fractures with lower BMIs, possibly because of less fat\nto cushion the hip when a fall occurs. <\/p>\n\n\n\n

     The vegans had lower average intakes of\ncalcium and protein from food. The average calcium intake of vegans was 591\nmilligrams per day, considerably below the approximately 1,000 milligrams per\nday which was the average for the other diet groups. However, even when only\nthose study participants who had calcium intakes above the U.K. recommendations\nwere examined, the vegans still had a higher risk of bone fractures. The\ndifferences in dietary protein and calcium intake do not account for all the\ndifferences in fracture risk between the groups and the researchers were unable\nto explain why differences in fracture risk persisted even after their data\nwere adjusted for differences in BMI and calcium and protein intake.<\/p>\n\n\n\n

     Additionally, there was a higher risk of\ntotal fractures among vegans who were not very physically active and who had a\nlow BMI but vegetarians (not vegans) with a higher BMI had a higher risk of hip\nfracture. There were a limited number of subjects who were in these subgroups\nwhich makes it difficult to be confident that these results would hold in a\nlarger group.<\/p>\n\n\n\n

What are the study\u2019s limitations?<\/strong><\/p>\n\n\n\n

While the\ninvestigators examined dietary calcium intake, they did not determine if there\nwere differences in intake of calcium supplements, nor did they investigate\nvitamin D intake or status. Adequate vitamin D is needed to promote calcium\nabsorption. They also did not investigate vitamin B12 status or intake.\nInadequate vitamin B12 is associated with an\nincreased fracture risk.<\/p>\n\n\n\n

     Because of the observational nature of\nthis study, it is not possible to say if changes in vegans\u2019 dietary or\nsupplement practices (such as increased calcium, vitamin D, vitamin B12, or\nprotein intake) could have affected their risk of fracture.<\/p>\n\n\n\n

Are there practical implications?<\/strong><\/p>\n\n\n\n

This study\nalerts vegans that they may be at increased risk for several types of fractures\nincluding hip and vertebral fractures. Vegans should follow general\nrecommendations to promote healthy bones including:<\/p>\n\n\n\n