A Study of Nearly 2 Million People Found That This Diet May Lower Cancer Risk
Key Points
Many of us want to do what we can to protect ourselves from cancer. And while many cancer risk factors are outside your control, a major new study suggests your daily eating habits may be one of the most powerful ways you can reduce your risk. Researchers analyzed health data from nearly 2 million people followed for up to 27 years and found that certain dietary patterns were linked to significantly lower risks for some of the most common cancers, including breast, prostate, kidney and colorectal cancer.
The findings, published in the British Journal of Cancer, are a comprehensive look at how different ways of eating—vegetarian, pescatarian, poultry-based versus red meat–heavy—stack up against each other when it comes to cancer risk. Here’s what the researchers found and what it means for what you put on your plate.
How Was This Study Conducted?
This was a pooled analysis of nine prospective cohort studies—a type of research that follows people over time and looks at what happens to them. Participants were classified into five diet groups at the start of each study based on what they reported eating: meat eaters (those who consume any red or processed meat), poultry eaters (chicken and turkey but no red or processed meat), pescatarians (fish but no meat or poultry), vegetarians (no meat or fish, but dairy and/or eggs are included) and vegans (no animal products at all).
In total, the analysis included 1,645,555 meat eaters, 57,016 poultry eaters, 42,910 pescatarians, 63,147 vegetarians and 8,849 vegans. Researchers tracked 17 different cancer types over follow-up periods ranging from six to 27 years. Results were adjusted for factors that could influence cancer risk, including smoking, alcohol intake, physical activity, BMI, diabetes history and, for women, hormone use and reproductive history.
What Did the Study Find?
The study found differences in cancer risk across diet groups for several cancer types.
Vegetarians had lower risks of pancreatic cancer (21% lower), breast cancer (9% lower), prostate cancer (12% lower), kidney cancer (28% lower) and multiple myeloma, a blood cancer (31% lower), compared to meat eaters. However, vegetarians also had a higher risk of squamous cell carcinoma of the esophagus—a type of throat cancer—at nearly double the risk of meat eaters.
Pescatarians fared well across several cancer sites: their risk of colorectal cancer was 15% lower, breast cancer 7% lower and kidney cancer 27% lower than meat eaters.
People who eat poultry but not red or processed meat showed a 7% lower risk of prostate cancer compared to meat eaters.
Vegans had a 40% higher risk of colorectal cancer compared to meat eaters—a surprising finding. But researchers caution that this was based on only 93 cancer cases among vegans and that the increased risk did not hold up in all sensitivity analyses. They speculate that low calcium intake, which is common among vegans, may be a contributing factor, since calcium has been associated with lower colorectal cancer risk.
The study has a few limitations to keep in mind. Diet was assessed at the start of the study and not tracked over time, so some participants’ eating patterns may have shifted. Dietary data was self-reported, which always leaves room for error. And the findings may not apply equally to populations outside Western Europe and North America, where most participants lived. The researchers also note that vegetarian diets vary widely—a diet heavy in refined carbohydrates technically qualifies, even though it offers far fewer health benefits than a vegetable- and legume-rich approach.
How Does This Apply to Real Life?
You don’t need to become fully vegetarian to potentially lower your cancer risk. This study suggests that even modest shifts in eating patterns may make a difference. Here are some practical takeaways:
- Consider a pescatarian approach. Eating fish in place of meat showed some of the most consistent protective associations in this study, particularly for colorectal, breast and kidney cancers.
- Fill your plate with plants. Vegetarian diets are generally higher in fiber, vitamins C and carotenoids, all of which may support cancer protection.
- If you eat meat, think about the type. Even shifting from red and processed meat toward poultry was associated with lower prostate cancer risk.
- If you’re vegan, pay attention to calcium and other nutrients. The study’s colorectal cancer finding in vegans may be tied to low calcium intake. But vegan options like fortified plant milks, almonds and leafy greens can all help you reach your calcium goals.234
Our Expert Take
A large-scale new study in the British Journal of Cancer found that vegetarian and pescatarian diets are linked to lower risks for several common cancers, including breast, prostate, kidney and colorectal cancer. The research reinforces what nutrition science has suggested for years: diets built around whole plant foods, with less red and processed meat, appear to support long-term health.