A large-scale international analysis has put the relationship between Vegetarian diets and the risk of cancerThe data, obtained from more than 1,8 million people followed for about 16 years, suggest that reduce or eliminate meat Dietary factors can offer clear protection against several common tumors, although they are not without nuances and possible adverse effects in other types of cancer.
The information comes from nine large cohort studies conducted in Europe, America and AsiaThe study, coordinated by the Cancer Epidemiology Unit at the University of Oxford and funded by the World Cancer Research Fund, compared regular meat eaters with poultry-only eaters, pescatarians, vegetarians, and vegans. The researchers observed that... Plant-based diets are associated with a more favorable cancer profileprovided that the diet is well planned and covers all nutritional needs.
An unprecedented study on vegetarian diet and cancer
This scientific consortium analyzed the health records of 1,8 million participants, including 1,64 million meat consumers, 57.016 people who consumed only poultry, 42.910 pescatarians, 63.147 vegetarians, and 8.849 vegans. The average follow-up was 16 years, enough time to record the appearance of 17 different types of cancer, from digestive tumors to hematological neoplasms.
The research, published in the British Journal of CancerShe controlled for factors such as body mass index, smoking, and other lifestyle habits, with the aim of isolating, as much as possible, the specific role of diet. According to Dr. Aurora Pérez-Cornago, lead researcher, this is the “most comprehensive analysis to date” on the relationship between Plant-based dietary patterns and cancer.
In the European context, these results align with the recommendations of public health organizations that have been calling for years reduce red and processed meat and increase consumption of fruit, vegetables, and fiber-rich foods. Although the study includes participants from countries such as the United Kingdom, the United States, India, and Taiwan, its findings are especially relevant for the European Unionwhere the burden of cancer remains very high.
According to the latest estimates, in the EU around 2,7 million people will receive a cancer diagnosis In 2026, despite a slight decrease in incidence compared to previous years, breast, prostate, colorectal, and lung cancers account for almost half of all cases, with men representing 54% of new diagnoses and 56% of deaths. In this context, any dietary change that allows lower the risk of cancer at the population level it is especially relevant.
Vegetarians have a lower risk of five common cancers
The most significant finding of the study is that the Vegetarians have a lower risk of five types of cancermany of them very frequent or serious. Compared to meat eaters, vegetarians showed:
- 31% lower risk of multiple myeloma, a type of blood cancer.
- 28% lower risk of kidney cancer.
- 21% lower risk of pancreatic cancer, one of the tumors with the worst prognosis.
- 12% lower risk of prostate cancer.
- 9% lower risk of breast cancer.
These five tumors represent approximately a fifth of cancer deaths in the United KingdomThis figure can be largely extrapolated to other European countries, where the distribution of cancer types is similar. The fact that dietary patterns can significantly influence the likelihood of developing these tumors reinforces the idea that diet is a key factor in cancer prevention.
The authors note that vegetarians tend to consume more fruit, vegetables and fiber and less red and processed meat, a pattern that aligns with dietary guidelines from institutions such as the WCRF or European health authorities. However, Professor Tim Key, an emeritus epidemiologist at Oxford and co-author of the study, points out that the difference in risk could be largely due to compounds found in meat that affect inflammatory or metabolic processes, rather than a "magical" effect of vegetables.
What does seem clear is that a diet rich in plant-based foods, accompanied by a very limited consumption of red and processed meat, is associated with a more favorable cancer risk profileThis message aligns with decades of prior research and with public health campaigns currently underway in several European countries.
Pescatarians and poultry consumers: partial benefits
The study does not limit itself to comparing carnivores with vegetarians, but also analyzes intermediate patterns, such as people who They include fish but not meat. (pescetarians) or those who exclusively consume poultry, avoiding red and processed meat. These groups also have some advantages in terms of cancer risk.
In the case of pescetarians, a lower risk of breast, kidney, and bowel cancer compared to red meat consumers. The authors suggest that the contribution of unsaturated fats and other nutrients from fish It could play a protective role by improving the inflammatory response and reducing oxidative damage in tissues.
For their part, those who They only eat birds Those that exclude red and processed meat showed a reduction in the risk of prostate cancerThis result supports the idea that the problem is not so much the presence of animal protein itself, but the type and amount of meat consumed, especially when it comes to processed products or those cooked at high temperatures.
For the Spanish and European population, where fish consumption is relatively high compared to other countries, this data aligns with the recommendation to opt for patterns similar to the Mediterranean diet: abundance of vegetables, legumes and whole grains, moderate presence of fish and poultry, and a very limited consumption of processed meats.
Professor Jules Griffin, from the Rowett Institute at the University of Aberdeen, emphasizes that there is a lack of studies that directly compare these patterns with a balanced omnivorous diet that follows the guidelines of Eatwell NHS or other European guidelines. According to this expert, a diet moderate in meat and fish, but rich in plant-based products, could be one of the most realistic strategies to reduce the risk of cancer associated with diet in the general population.
Risks and weaknesses: not all vegan diets offer the same protection
Despite the observed benefits, the study also identifies specific risks associated mainly with very restrictive dietsparticularly vegans who are not well-planned. One of the most striking findings is that the vegans in the study presented a 40% higher risk of colorectal cancer than those who ate meat.
This increase is provisionally attributed to a insufficient intake of calcium and other micronutrients, Deficiencies you should watch out for in a vegan dietIn the vegan group, the average calcium intake was around 590 mg per day, below the official UK recommendation (700 mg per day) and European guidelines, which are generally around 1.000 mg for the adult population. Calcium can to bind to fatty acids and other substances in the intestinereducing its potential to cause harm to the colon mucosa.
In addition, the study found that vegetarians had almost twice the risk of esophageal squamous cell carcinoma compared to meat consumers. Researchers point to possible deficiencies in B vitamins, such as riboflavin or the Vitamin B12which are more abundant in products of animal origin and whose lack can affect the health of epithelial tissues.
However, the authors themselves insist that these results should to be interpreted with cautionIn the case of colorectal cancer in vegans, the total number of cases was relatively low, which increases statistical uncertainty. Furthermore, the differences in current dietary habits Compared to 10, 20 or 30 years ago, the landscape can change: nowadays it is more common to find plant-based foods enriched with calcium and vitamins, such as fortified plant-based drinks, which could reduce the risk of nutritional deficiency.
experts like Aisling DalyProfessors of nutrition at Oxford Brookes University remind us that a vegetarian or vegan diet is not automatically "healthy" simply by excluding meat. If it is not They replace animal products with nutritious alternatives And even if planned, the expected benefits may not materialize and new health problems may even appear.
Changes in plant-based eating patterns and their future impact
Another point the researchers make is that the people included in these studies were, in many cases, recruited more than a decade agoDuring that time, vegetarian and vegan diets have changed significantly, especially in Europe and the United States.
In the past, those who followed these patterns usually based their diet on whole-grain foods such as vegetables, fruits, legumes, whole grains, nuts, and seeds. Currently, the supply of ultra-processed plant-based products (vegan burgers, vegetable sausages, snacks, processed desserts, etc.) has grown exponentially, which can influence the actual nutritional profile of a meat-free diet.
The nutrition scientist Nerys AstburyA researcher from Oxford University warns that many modern plant varieties may not be as healthy as those from previous decades, due to the increased consumption of ultra-processed foodsIn light of this warning, the impact of current vegetarian and vegan diets on cancer risk could differ from that observed in the study, which reflects eating habits from another era.
The levels of certain key nutrients have also changed. More recent data suggest that today, thanks to the use of products enriched with calcium and vitaminsThe differences in calcium intake between vegans and omnivores have decreased in many European countries. If this is confirmed in the long term, it is possible that the increased risk of colorectal cancer observed in vegans in this historical analysis will be mitigated. do not reproduce in future generations.
The introduction itself of new, better-formulated vegan options And nutritional education campaigns can help those who completely eliminate animal products to have a more balanced diet, reducing the risk of deficiencies in vitamin B12, riboflavin, iron or zinc, which are relevant micronutrients also in the prevention of some cancers.
What do these findings mean for cancer prevention in Europe?
In a continent where cancer remains one of the leading causes of death and disabilityThe results of this study reinforce the message of prevention guidelines: diet can help reduce risk, but it must be approached judiciously. The available evidence supports the patterns rich in plant-based foods -fruit, vegetables, legumes and whole grains- and the reduction of meat, especially red and processed meat.
In practice, this translates into promoting diets that prioritize Plant-based dishes, with a moderate or low presence of animal productsand to advise against the regular consumption of sausages, cured meats, bacon, and other highly processed meat products. Both European authorities and international organizations such as the WCRF agree that these products are associated with a increased risk of colorectal cancer and other chronic conditions.
At the same time, the study cautions against simplistic views. Vegetarian and vegan diets can be healthy and nutritionally adequateHowever, they can also provide less protein, saturated fat, and certain micronutrients than omnivorous diets. For many people, a reasonable strategy might be to move closer to a predominantly plant model without completely eliminating foods such as fish, dairy products or eggs, always within a globally balanced pattern.
In Spain, where the traditional Mediterranean diet It already combines a high presence of vegetables, olive oil and legumes With a relatively low intake of red meat, this data provides further support for policies that promote a more plant-based diet. Adjusting meat consumption to moderate amounts and opting for alternative protein sources (legumes, nuts, soy, fish) could help to contain the impact of cancer in the population in the medium and long term.
In light of this extensive analysis, the idea that emerges is that The key is not just to stop eating meat, but to build a well-thought-out plant-based diet.Rich in fresh foods, with sufficient calcium and B vitamins, and with very limited use of ultra-processed foods, this diet maximizes the benefits of vegetarian diets in reducing the risk of various types of cancer, while minimizing the potential weaknesses identified in less balanced vegan and vegetarian diets.
