For a long time, researchers have studied diet as a possible factor in the development of cancer. Previous research has indicated that meat consumption is associated with a higher risk of certain types of cancer. A new study has found that people who eat less meat have a lower risk of getting all types of cancer. However, the study cannot prove the cause, and the association between meat consumption and cancer risk may be due to other variables.
Researchers at the University of Oxford, UK, recently published the results of a large study looking at the effect of different levels of meat consumption on the likelihood of developing cancer. The study found that vegetarians, pescatarians (fish eaters) and people who eat little meat have a significantly reduced risk of developing cancer.
The study authors analyzed statistics regarding cancer cases in general and also took a close look at the effect of meat consumption on three of the most common cancers: postmenopausal breast cancer, prostate and colorectal cancer.
The results of this study provide further evidence that following a vegetarian, pescatarian or low-meat diet may be associated with a lower risk of being diagnosed with cancer. These results also suggest that cancer risk for different diet groups may be different across cancer types. The study is published in reliable BMC MedicineSource.
More than 450,000 people followed for 11 years
The researchers followed 472,377 people in the UK Biobank database over an average period of 11 years. None of the participants, who were between the ages of 40 and 70 when the team recruited them between 2006 and 2010, had been diagnosed with cancer at the start of the study period. During the study, people told researchers about their meat consumption.
The researchers divided the study cohort into four groups:
– Meat eaters reported eating processed meat, poultry or red meat, including beef, pork and lamb, more than five times a week. This group numbered 247,571 people, or 52.4% of the total study population.
– People who ate little meat ate the same foods, but at most five times a week. This group represented 43.5% of the study population, or 205,385 people.
– People who eat fish but no meat, represented 10,696 people, or 2.3% of the population studied.
– Vegetarians and vegans, who ate neither meat nor fish, made up 1.8% of the entire cohort, or 8,685 people.
Due to the large number of cancer cases in the UK Biobank, the researchers were able to examine the most common types of cancer in relation to diet groups, despite low numbers of vegetarians and pescatarians, and explore this association further. in depth. By the end of the study period, 54,961 people had developed cancer of some type. The researchers found 5,882 cases of colorectal cancer, 9,501 cases of prostate cancer, and 7,537 cases of postmenopausal breast cancer.
Reduce the risk of cancer
The group of meat eaters serving as a reference, the researchers calculated the risk of developing cancer for the other three groups. The data showed that the group of vegetarians and vegans was 14% less likely to develop cancer than the other groups.
Fish eaters had a 10% lower risk of developing cancer, and people who ate little meat reduced their risk by 2%.
Postmenopausal women who were vegetarians had an 18% lower risk of breast cancer, while pescatarian and vegetarian men had a 20% and 31% lower risk of prostate cancer, respectively. When the study authors looked at colorectal cancer, they found that people who ate little meat had a 9% lower risk of developing the disease, which they note is consistent with previous research.
Behind the data
The authors conclude: “It is not clear whether the other differences observed for all cancers and for prostate cancer reflect causal relationships or are due to other factors, such as residual confounding factors or differences in the detection of cancer. Among these potential confounders is body mass index (BMI). When researchers took BMI into account, the reduction in breast cancer risk among vegetarian women became insignificant. BMI would be a potential confounder if differences in BMI by diet groups were not due to dietary differences.
For example, maybe vegetarians exercise more than meat eaters and maintain a healthy BMI as a result. Furthermore, there are differences in BMI by diet group, and a higher BMI is associated with a higher risk of cancer.
The recommendations of the researchers
The researchers conclude from their study that individuals should be advised to limit the consumption of processed meat and red meat in their diet and consume a diet rich in whole grains, fruits, vegetables and beans while maintaining a healthy body weight. The study authors found that vegetarians and pescatarians were more likely to be young and well-educated and less likely to smoke and drink. This suggests that it is possible that the results are due to confounding factors.
Risk of cancer in regular and low meat-eaters, fish-eaters, and vegetarians: a prospective analysis of UK Biobank participants