"But if you look at tofu, which is processed so there is more energy going into its production, when you correct for the fact that the protein in it is not as digestible compared to the meat-based products, you can see that it could actually have a higher global warming potential than any of the monogastric animals". Vegetarians and people who only eat fish also have an increased chance of hip fractures compared to carnivores.
More studies are needed from different populations, including from non-Europeans, as well as cohorts with a larger proportion of men, they said.
The study, which incorporated around 55,000 people of varying diets, discovered that fish-based and vegetarian diets shared a small but significant increase in risk of bone fracture, while veganism put participants at a 43 percent higher risk of fractures.
Looking at medical records of nearly 55,000 healthy individuals-a mix of meat eaters, pescatarians, vegetarians, and vegans-over an average of 18 years, the researchers identified 3,941 bone fractures. Lead study author Tammy Tong explains to New Scientist, "Unless they are actively supplementing, it's quite unlikely that vegans will have a sufficient intake of calcium just from the diet".
Around 29,400 ate meat, almost 17,500 were vegetarians or vegans and just over 8,000 were fish eating pescatarians.
Participants filled out questionnaires that involved questions about their diet, smoking habits, alcohol consumption, dietary supplement use, and more. (Supplement intake was not assessed.) Fracture risk was tracked through 2016 through National Health Service records collected in England, Scotland and Wales.
During the time of the study, 3,941 fractures occurred in total, including 566 arms, 889 wrists, 945 hips, 366 legs, 520 ankles, and 467 fractures at other main sites, defined as the clavicle, ribs, and vertebrae.
Compared with people who ate meat, vegans with lower calcium and protein intakes (on average) had a 43 percent higher risk of fractures anywhere in the body, researchers have warned.
"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", Tong said in the press release.
Yet risk among non-meat eaters still remained significantly higher. Why?
According to a study published today in BMC Medicine, vegetarians and pescatarians also had an elevated risk, but it was lowered when they made a concerted effort to include protein- and calcium-rich foods on their plates.
"This is the first prospective study of diet group with both total and multiple specific fracture sites in vegetarians and vegans, and the findings suggest that bone health in vegans requires further research", the researchers wrote.
Dr Nagra said the disparity in the intake levels would obviously impact the results since the vegan group was consuming calcium levels lower than the United Kingdom recommendations of 700mg/day.
Vegans are at greater risk of breaking bones, new research shows. Here is what you need to know about the vegan diet.