Vegetarian Diets Linked to Lower Cancer Risk, Fresh Study Finds

A landmark study published in the British Journal of Cancer reveals that vegetarian diets are associated with a significantly lower risk of developing several types of cancer, including pancreatic, breast, kidney, prostate cancer, and multiple myeloma. However, the research also indicates a heightened risk of squamous cell carcinoma of the oesophagus among vegetarians.

Largest Study of its Kind

The research, led by scientists at Oxford Population Health’s Cancer Epidemiology Unit and funded by the World Cancer Research Fund, is the largest of its kind, analyzing data from over 1.8 million individuals across three continents – the UK, US, Taiwan, and India – over an average of 16 years. The study compared cancer risks across five dietary groups: meat-eaters, poultry eaters (those who avoid red and processed meat), pescatarians (fish eaters), vegetarians (who consume dairy and/or eggs), and vegans.

Specific Cancer Risk Reductions

Compared to meat-eaters, the study found:

• A 21% lower risk of pancreatic cancer
• A 9% lower risk of breast cancer
• A 12% lower risk of prostate cancer
• A 28% lower risk of kidney cancer
• A 31% lower risk of multiple myeloma

Increased Risk of Oesophageal Cancer

Conversely, vegetarians demonstrated nearly double the risk of squamous cell carcinoma of the oesophagus. Researchers noted that vegans had a 40 percent higher risk of bowel cancer, the fourth most common cancer in the UK.

Nutrient Intake and Potential Explanations

Researchers suggest that the increased risk of certain cancers among vegetarians may be linked to lower intakes of specific nutrients. For example, inadequate calcium intake could potentially increase the risk of colorectal cancer, even as vitamin B2 deficiency might contribute to a higher risk of oesophageal cancer. However, these remain hypotheses requiring further investigation.

Study Limitations and Future Research

The Vegan Society highlighted that the increased risk of oesophageal cancer was based on a relatively small number of cases (31) across three studies. The study participants were primarily recruited in the 1990s and early 2000s, a period when plant-based foods were less commonly fortified with essential nutrients and awareness of micronutrient supplementation was lower.

Expert Commentary

Dr. Aurora Pérez-Cornago, a senior Nutritional Epidemiologist and lead investigator of the study, stated, “This study is really excellent news for those who follow a vegetarian diet since they have a lower risk of five cancer types, some of which are very prevalent in the population.”

Dr. Helen Croker, assistant director of research and policy at the World Cancer Research Fund, advises, “To increase your overall protection from cancer, our advice is to build meals around wholegrains, pulses, fruit and vegetables, and avoid processed meat and limit red meat.”

Plant-Based Diets and Overall Health

Recent research continues to support the health benefits of plant-based diets. Studies have indicated that plant-based diets may cut the risk of certain cancers by up to 25 percent, and regular consumption of chicken could double the risk of dying from gastrointestinal cancer. Plant-based diets have been linked to slowing the progression of prostate cancer and reducing the risk of colorectal cancer.

Key Takeaways

• Vegetarian diets are associated with a lower risk of pancreatic, breast, kidney, prostate cancer, and multiple myeloma.
• Vegetarians may have an increased risk of squamous cell carcinoma of the oesophagus.
• Nutrient intake may play a role in cancer risk within vegetarian diets.
• A diet rich in wholegrains, pulses, fruits, and vegetables is recommended for overall cancer prevention.