Vegetarian Diets Linked to Lower Cancer Risk, But Higher Risk of One Type

New research suggests that vegetarian diets are associated with a reduced risk of several cancers, but may increase the risk of one specific type. The large-scale study, led by researchers at Oxford Population Health and funded by the World Cancer Research Fund, analyzed data from over 1.8 million people across three continents.

Lowered Risk of Multiple Cancers

Compared to meat eaters, vegetarians in the study demonstrated a significantly lower risk of several cancers, including:

• Pancreatic Cancer: 21% lower risk
• Breast Cancer: 9% lower risk
• Prostate Cancer: 12% lower risk
• Kidney Cancer: 28% lower risk
• Multiple Myeloma: 31% lower risk

Increased Risk of Oesophageal Squamous Cell Carcinoma

However, the study also found that vegetarians had nearly double the risk of oesophageal squamous cell carcinoma, the most common type of oesophageal cancer. Researchers suggest this may be due to lower intakes of certain nutrients more abundant in animal foods. Source

Dietary Variations and Cancer Risk

The study categorized participants into five diet groups: meat eaters, poultry eaters (no red or processed meat), pescatarians (fish eaters), vegetarians (eat dairy and/or eggs), and vegans. Pescatarians showed lower risks of breast, kidney, and bowel cancers, while poultry eaters had a lower risk of prostate cancer. Source

Vegan Diets and Colorectal Cancer

Vegans, who exclude all animal products, had a statistically significant higher risk of colorectal (bowel) cancer compared to meat eaters. Further research is needed to confirm these findings and understand the underlying reasons. Source

Study Details and Limitations

The research, published in the British Journal of Cancer, included data from the UK and US, encompassing 1.64 million meat eaters, 57,016 poultry eaters, 42,910 pescatarians, 63,147 vegetarians, and 8,849 vegans. Researchers acknowledge that the numbers of cases for some cancers were small, limiting the certainty of some findings. Variations in nutrient intake and overall diet quality within vegetarian populations also pose a challenge for definitive conclusions.

Expert Commentary

“Vegetarians typically consume more fruit, vegetables and fibre than meat eaters and no processed meat, which may contribute to lower risks of some cancers,” said Aurora Perez Cornago, principal investigator of the study. Source

Dr. Helen Croker, Assistant Director of Research and Policy at World Cancer Research Fund International, emphasized the importance of evidence-based dietary choices: “We funded this research because people deserve evidence they can trust as they consider eating less meat and this study provides the most comprehensive evidence yet on vegetarian and non-meat diets and cancer risk.” Source

Recommendations for Cancer Prevention

The World Cancer Research Fund recommends building meals around wholegrains, pulses, fruit, and vegetables, avoiding processed meat, and limiting red meat consumption to increase overall protection from cancer. Source