RAC member, Paul Appleby, introduces a major new paper he co-authored from EPIC-Oxford, a long-term study focussing on the health of vegetarians and vegans.
The research was conducted by the Nuffield Department of Population Health at the University of Oxford and the findings were published in late November 2020. Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study, can be found in the open access journal, BMC Medicine.
The first two paragraphs from the press release issued by the journal summarised the findings:
Compared with people who ate meat, vegans ... had a 43% higher risk of fractures anywhere in the body (total fractures), as well as higher risks of site-specific fractures of the hips, legs and vertebrae ... Vegetarians and people who ate fish but not meat had a higher risk of hip fractures, compared to people who ate meat. However, the risk of fractures was partly reduced once body mass index (BMI), dietary calcium and dietary protein intake were taken into account.
Dr Tammy Tong, Nutritional Epidemiologist at the Nuffield Department of Population Health, University of Oxford, and the lead author said: “This is the first comprehensive study on the risks of both total and site-specific fractures in people of different diet groups. We found that vegans had a higher risk of total fractures which resulted in close to 20 more cases per 1000 people over a 10-year period compared to people who ate meat. The biggest differences were for hip fractures, where the risk in vegans was 2.3 times higher than in people who ate meat, equivalent to 15 more cases per 1000 people over 10 years.”
Unsurprisingly, the paper’s findings caused some concern in vegan circles, although, quoting Dr Tong, the press release went on to point out that:
“Previous studies have shown that low BMI [body mass index, a measure of obesity] is associated with a higher risk of hip fractures, and low intakes of calcium and protein have both been linked to poorer bone health. 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. 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.”
In other words, vegetarians and especially vegans should ensure that their diet contains adequate amounts of calcium and protein, and that they are maintaining or working towards a healthy weight. In the UK, the reference nutrient intake for calcium (the quantity considered sufficient for 97.5% of the population) is 700 milligrams (mg) per day, although in the US and Canada the recommended daily allowance is 1000 mg per day in adults, or 1200 mg per day in women over 50 and men over 70. These quantities are considerably higher than the estimated average calcium intake of vegans in the study. The Vegan Society lists calcium-set tofu, calcium-fortified milk and yoghurt alternatives and soya and linseed bread fortified with extra calcium as particularly good sources of calcium (with more detailed information in a linked PDF file), whilst pointing out that bone health depends on several nutrients including vitamins D and K and protein, as well as calcium. Brenda Davis, Registered Dietitian in the USA and co-author of the excellent Becoming Vegan, also has a short video illustrating some vegan sources of calcium on her website. Vegan Health is a great source of US-focused information written by dietitians too.
Full text available here
“The publication of this paper presents an opportunity for us to talk about bone health, which is an important topic for everyone. There are many ways for us to look after our bones and I’ve outlined several practical tips in a recent news article about this research."
Vegan Society Dietitian, Heather Russell