What a dietitians' position paper and the WHO report on plant-based eating and cancer.
Vegan Brief·Evidence last reviewed July 10, 2026
This is a summary of the cited evidence, not medical advice.
Vegetarians~18% lower overall (meta-analysis)
Processed meatCause of colorectal cancer
Study typeObservational cohorts and meta-analysis
01
The short version
Does eating plants lower your risk of cancer? As of 2026 the honest answer is a qualified yes, and the two halves of it deserve different confidence. The firmer half is what a plant-based plate leaves off. The softer half is the overall benefit from what it adds, which is real but modest and drawn almost entirely from observational studies. Start with the plant side, where the Academy of Nutrition and Dietetics summarises the Adventist cohort.
Primary source 01 / 05
vegetarian diets are associated with a lower overall cancer risk, and especially a lower risk of gastrointestinal cancer
That is an association from people who already eat this way, so it shows a link rather than proof, and the group studied was health-conscious to begin with. The pooled numbers put the overall effect in modest territory rather than dramatic. A meta-analysis of seven studies landed on a similar figure, reporting
Primary source 02 / 05
vegetarians having an 18% lower overall cancer incidence than nonvegetarians
The sturdier evidence runs the other way, from the food a plant-based diet removes. In 2015 the World Health Organization's cancer agency reviewed the data and put a number on processed meat and bowel cancer.
Primary source 05 / 05
An analysis of data from 10 studies estimated that every 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by about 18%.
That finding, covered in full on our processed meat and cancer page, is the one the WHO states most directly, and a plant-based plate sidesteps it by design. The two halves point the same direction from different kinds of evidence: the WHO classifies processed meat as carcinogenic, while the finding that plants lower total cancer risk comes from observational studies and is modest in size.
It lowers the odds modestly rather than preventing it. A meta-analysis found vegetarians had about 18% lower overall cancer incidence, and vegans looked slightly better again, including about 35% lower prostate cancer risk. These are observational associations, so they show a link rather than proof.
Which cancer finding do the sources state most directly?
The most direct statement is about avoidance: the WHO classifies processed meat as a cause of colorectal cancer, with about an 18% higher risk for every 50 grams eaten daily. A plant-based diet skips that exposure entirely.
The primary sources
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