A new study finds that eating meat five times or less a week reduces overall cancer risk.
Cody Watling and Colleagues from the University of Oxford, UK, investigated the relationship between diet and cancer risk to understand the impact of eating meat on disease prevalence. Research has previously shown that it is estimated that 30-40% of all kinds of cancer can be prevented with a healthy lifestyle and dietary measures.
The study was published in the open-access journal BMC Medicine.
Studying the prevalence of eating meat
The researchers analysed data collected from 472,377 British adults who were recruited to the UK Biobank between 2006 and 2010. Participants, who were aged between 40 and 70 years, reported how frequently they ate meat and fish and the researchers used this data to calculate the incidence of new cancers that develop over an average period of 11 years using health records.
The data accounted for diabetes status and sociodemographic, socioeconomic and lifestyle factors in their analysis. 247,571 (52%) of participants were consuming meat more than five times per week, 205,382 (44%) of participants recorded eating meat five or fewer times per week, 10,696 (2%) ate fish but not meat, and 8,685 (2%) were vegetarian or vegan. 54,961 participants (12%) developed cancer during the study period.
Overall cancer risk
The researchers found that overall cancer risk was 2% lower amongst those who ate meat five times or less per week, 10% lower amongst those who ate fish but not meat, and 14% lower amongst vegetarians and vegans, compared to those who ate meat more than five times per week. When comparing the incidence of specific cancers with participants’ diet, the authors found that those who were consuming meat five times or less per week had a 9% lower risk of colorectal cancer, compared to those who ate meat more than five times per week.
Furthermore, the researchers found that the risk of prostate cancer was 20% lower amongst men who ate fish but not meat and 31% lower amongst men who followed a vegetarian diet, compared to those who ate meat more than five times per week. Post-menopausal women who followed a vegetarian diet had an 18% lower risk of breast cancer than those who were consumed meat more than five times a week. However, the findings suggested that this was due to vegetarian women tending to have a lower body mass index (BMI) than women who ate meat.
However, the researchers cautioned that the observational nature of their study does not allow for conclusions about a causal relationship between diet and cancer risk. Additionally, as UK Biobank dietary data was collected at a single time-point, rather than over a continuous period of time, it may not be representative of participants’ lifetime diets.
The authors suggested that future research could investigate the associations between diets containing little or no meat and the risk of individual cancers in larger populations with longer follow-up periods.
