August 19, 2025, 2:19 am | Read time: 7 minutes

Study with More Than 79,000 Participants

A recent study by Loma Linda University in California provides new insights into the relationship between plant-based diets and the risk of various cancers. As part of the “Adventist Health Study-2,” 79,952 adults in the U.S. and Canada were observed over an average of 7.3 years. The results suggest that a low-meat diet can reduce cancer risk. They were published in August 2024 in the American Journal of Clinical Nutrition.

At the start of the study, none of the participants had cancer. Researchers analyzed the health data of the subjects during the study and recorded around 7,300 newly diagnosed cancer cases. The data were evaluated concerning different dietary patterns—including meat-based, vegetarian, vegan, and pescatarian diets.

The Results

Vegetarians had up to a 45 percent lower risk of stomach cancer compared to regular meat eaters. The risk of lymphomas was also reduced by 25 percent. Vegans showed a 24 percent lower overall risk for all observed types of cancer. Particularly among younger men, the risk of prostate cancer was 43 percent lower for those following a vegan diet.

As this is an observational cohort study, no causal relationship can be proven. The authors note that other factors, such as body weight, lifestyle, or medical care, could also influence the results.¹

A Study from 2022 Supports These Findings

According to the World Health Organization (WHO), cancer is the second leading cause of death worldwide. However, 30 to 50 percent of all cases are preventable through preventive measures, including a healthy diet.² A large-scale study by the University of Oxford in 2022 observed meat and fish eaters as well as vegetarians over eleven years. They discovered which dietary pattern—whether low or high in meat—can demonstrably reduce cancer risk.³

For their study, the scientists used data from 472,377 Britons from the UK Biobank, a biomedical database and research resource. Participants were divided into three categories based on questions about their diet:

• Regular meat eaters (eat meat more than five times a week, 53 percent of participants)
• Occasional meat eaters (eat meat five times or less a week, 44 percent of participants)
• Pescatarians (eat fish, just over two percent of participants)
• Vegetarians and vegans (eat neither meat nor fish, just under two percent of participants)

At recruitment, none of the subjects had cancer. Subsequently, the medical records of the participants were observed for eleven years. Other factors such as age, gender, smoking, alcohol consumption, and sociodemographic status were also considered.

Which Type of Diet Reduces Cancer Risk?

After an average of 11.4 years, the medical records of the study participants were evaluated. A total of 54,961 cancer cases were identified. Based on the dietary habits of the subjects, it was found: Compared to regular meat eaters, the cancer risk was two percent lower for those with a low-meat diet, ten percent lower for pescatarians, and 14 percent lower for vegetarians.

Risk for Specific Cancers Also Decreases

The annual number of new cases of all cancers is 493,250 (as of 2019/2020).⁴ In the United Kingdom, where the study was conducted, colorectal cancer, breast cancer, and prostate cancer are the most common types of cancer. In Germany, men most frequently develop prostate cancer, followed by lung and colorectal cancer, while women most frequently develop breast cancer, followed by colorectal and lung cancer.

Among the subjects, there were 5,882 cases of colorectal cancer, 7,537 cases of postmenopausal breast cancer, and 9,501 cases of prostate cancer. A clear correlation between cancer incidence and diet was observed.

Also interesting: How Diet Can Affect Menstruation–Positively or Negatively

Colorectal Cancer

People with a low-meat diet had a nine percent lower cancer risk for colorectal cancer compared to those who regularly consumed meat. This result aligns with a study published in 2015, which found that a higher intake of processed meat is associated with an increased risk of colorectal cancer.⁵ According to the World Cancer Research Fund (WCRF), red meat also increases the risk. Whole grains and dairy products, on the other hand, have a risk-reducing effect.⁶

Breast Cancer

Women who followed a vegetarian diet had an 18 percent lower risk of postmenopausal breast cancer compared to regular meat eaters. As the study authors explain, this could also be due to the generally lower average body weight of vegetarians. The WCRF warns that being overweight or obese in adulthood can increase the risk of postmenopausal breast cancer. Furthermore, according to the WCRF, there is evidence that consuming dairy products and non-starchy vegetables may reduce the risk of breast cancer.⁷

Prostate Cancer

Compared to regular meat eaters, pescatarians and vegetarians had a 20 percent and 31 percent lower risk, respectively, of developing prostate cancer. The study leaders suggest that, in addition to diet, other factors may play a significant role, such as whether a person undergoes cancer screening. This also applies to other types of cancer. The WCRF states that there is evidence that a high consumption of dairy products and a calcium-rich diet may increase the risk of prostate cancer.⁸

More on the topic

Study Summary How Diet Is Linked to Cancer Risk

"Highway to Health: A Study Overview" Regardless of Diet! Study Finds Nutrient Deficiencies in Many Young People

Limitations of the Study

Whether the observed correlations depend solely on diet cannot be definitively assured, according to the scientists. Other factors, such as personal lifestyle, etc., may have influenced the results.

Additionally, about 94 percent of the subjects were white, so it cannot be assumed that the same correlations can be found in other ethnic groups. It is also important to emphasize that abstaining from meat or following a low-meat diet does not automatically mean that a person is eating healthier.

How Much Meat Should Be on the Plate?

The study confirms once again: A balanced and low-meat diet, primarily consisting of vegetables, fruits, and whole grains, can reduce health risks such as cancer risk. While a purely pescatarian or vegetarian diet has a stronger effect, those who do not want to completely give up meat can still benefit their health by limiting the amount.

A large-scale umbrella review from 2024 analyzed study data from 2000 to 2023, which focused on vegetarian and vegan diets. Here, too, it was confirmed: A diet free of meat reduced the risk of developing cancer.⁹

Scientifically tested dietary principles, such as the nutrition circle of the German Nutrition Society, can be used as guidelines for a low-meat diet. These food-based dietary recommendations were updated in 2024. Per week, one to two servings of fish and meat of 120 grams each can be enjoyed. Two weekly servings of sausage of 30 grams each are also allowed.¹⁰