A large scientific study has revealed that reducing or refraining from eating meat may contribute to reducing the risk of some types of cancer, but may instead be associated with an increased risk of colorectal cancer, especially among pure vegetarians.
These findings come more than a decade after the World Health Organization classified processed meat as a category 1 carcinogen, placing it in the same category as scientific evidence relating to smoking, alcohol and asbestos.
This classification is based on research showing that eating about 50 grams of processed meat each day can increase your risk of colon cancer by about 20%. Red meat was also classified as “possibly carcinogenic”, but to a lesser extent.
Largest study of its kind
The new study, conducted by researchers at the University of Oxford, is the largest study to date of the link between a meat-free diet and cancer risk.
Scientists analyzed the risk of 17 different types of cancer across five dietary categories, including meat eaters and vegans.
The analysis was based on data collected between 1980 and 2010 on more than 1.8 million people in the UK, US, Taiwan and India, with an average follow-up of 16 years.
During this period, more than 220,000 cancer cases were recorded, the most prominent of which were breast cancer, followed by prostate, colon, and rectal cancers.
mixed results
The results showed that in addition to having a lower incidence of multiple leukemia, vegetarians were less likely to develop pancreatic, breast, prostate, and kidney cancer.
However, researchers found that pure vegetarians had up to a 40% higher risk of developing colorectal cancer than meat eaters, and also had an increased risk of developing esophageal cancer, particularly squamous cell carcinoma.
Professor Tim Kee, one of the study’s co-authors and an expert on the link between food and cancer, said the results showed that “a diet rich in fruits, vegetables and fiber and avoiding processed meat is recommended to reduce cancer risk, but cutting out meat is not without risks.”
possible explanation
Researchers suggested that vegetarians’ low calcium intake may contribute to an increased risk of colon cancer, since calcium deficiency is a known risk factor. Data shows that vegetarians eat the most fiber, the least alcohol, and the least calcium, two factors thought to protect against colorectal cancer.
The researchers also noted that the meat eaters in the study had lower intakes than the general UK average, which may have influenced the results. Adults in the UK typically consume around 34 grams of meat per day, but the participants consumed less than half that amount.
broader health situation
These results come at a time when colorectal cancer remains one of the most common types of cancer worldwide, with a notable increase in cases in people under 50, despite a decline in cases in older people thanks to early screening programs.
Cancer Research UK estimates that around 5,400 cases of bowel cancer in the UK each year are linked to the consumption of processed meat.
Although vegetarian diets are often associated with low saturated fat and high fiber, the researchers emphasized that this study was observational and did not prove a direct cause-and-effect relationship, and that vegetarian diets are often defined by what you don’t eat, rather than what you actually eat, and their components vary widely.
The researchers concluded that the overall picture looks positive for vegetarians when it comes to some types of cancer, but stressed the importance of replenishing missing nutrients with supplements and fortified foods to ensure a balanced diet that reduces potential health risks.
