People who avoid meat are less likely to develop a range of cancers, according to one of the most detailed studies of vegetarian diets to date.
The research followed nearly 80,000 members of the Seventh-day Adventist Church in North America — many of whom follow plant-based diets — for an average of almost eight years each. None had cancer at the outset. Their diet was recorded in detail and their health tracked.
Overall the results showed that vegetarians had a 12 per cent lower risk of developing cancer than meat eaters in the same community.
The biggest reductions were for colorectal cancer (21 per cent lower risk), stomach cancer (45 per cent lower), and lymphoproliferative cancers such as lymphoma (25 per cent lower).
Analysing the data by diet type showed further patterns. Vegans, who eat no animal products, had the largest overall reduction in cancer risk: 24 per cent lower than meat eaters. This included lower rates of breast cancer and, in younger men, prostate cancer.
Lacto-ovo vegetarians, who eat dairy and eggs, showed protection against some blood cancers. Pesco-vegetarians or pescatarians, who eat fish but no other meat, had notably fewer colorectal cancers. The differences between vegetarians and meat eaters were not limited to diet. On average the vegetarians were leaner, smoked and drank less, exercised slightly more and were more likely to have a university degree. They were less likely to have used hormone replacement therapy or oral contraceptives. • Vegetarians are more power-hungry than meat eaters — why? The study took these factors into account but it was impossible to say to what degree the differences in cancer outcomes were caused by what different groups were eating. Britain is facing a growing cancer challenge. Survival rates have doubled since the 1970s and most young patients live at least a decade after diagnosis but the NHS is under strain from long waiting times and an ageing population. About 395,000 people are diagnosed with a form of the disease each year. Among under-50s cancer cases have risen by almost a quarter since the mid-1990s, driven partly by obesity, sedentary lifestyles and diets high in fat, sugar and salt and low in fibre. Premature deaths caused by cancer cost the economy an estimated £10.3 billion a year, with £3.2 billion of that from those under 50. The study’s authors say that, while vegetarian diets are not a magic bullet, they appear to offer protection against several cancers with minimal risk of harm, making them a potentially valuable part of prevention strategies. • 10 easy vegetarian recipes that non-veggies will love too The researchers are based at Loma Linda University, a Seventh-day Adventist institution in California. The findings are published in The American Journal of Clinical Nutrition. Dr Tilman Kuhn of Queen’s University Belfast, who was not involved in the study, said that the reduced risk for vegetarians of developing gastrointestinal cancers was unsurprising. “Diets low in meat and high in fibre, via wholegrains, fruits and vegetables, have been shown to be associated with lower risks of these cancers in other populations,” he said. The results in breast and prostate cancer were more surprising given that other studies have not suggested a strong role for animal products or other dietary risk factors. “The results on lymphoma are surprising and new, as underlying mechanisms are not known,” he said. “The study is one of the few studies worldwide with meaningful numbers of vegans and vegetarians under long-term observation. Comparing long-term diets is a powerful research model.”