The consumption of meat, mainly processed meat and unprocessed red meat, has been linked to an increased risk of type 2 diabetes, as revealed in a comprehensive analysis of data from nearly two million participants, detailed in a new publication in The Lancet Diabetes and Endocrinology.
Global meat production has surged in recent years, and consumption levels in many countries now surpass the recommended dietary guidelines. Earlier studies have suggested that high intakes of both processed and unprocessed red meat could lead to a heightened risk of type 2 diabetes. However, these findings have often been inconsistent and inconclusive.
In contrast, poultry, including chicken, turkey, and duck, is frequently considered a healthier alternative to red and processed meats. Despite this common perception, relatively few studies have explored the link between poultry consumption and the risk of developing type 2 diabetes.
A research team from the University of Cambridge, collaborating under the global InterConnect project, analysed data from 31 cohort studies spanning 20 countries to address these gaps. Their thorough analysis considered various factors, including age, gender, health-related behaviours, caloric intake, and body mass index.
The findings revealed that regular consumption of 50 grams of processed meat per day — roughly equivalent to two slices of ham — was associated with a 15% increased risk of developing type 2 diabetes within the next decade. Similarly, consuming 100 grams of unprocessed red meat daily — about the size of a small steak — was linked to a 10% increased risk. Interestingly, consuming 100 grams of poultry per day was initially found to carry an 8% higher risk of type 2 diabetes. Still, this association weakened under further analysis, whereas the links for red and processed meats remained robust.
Professor Nita Forouhi of the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, a senior author of the study, highlighted the significance of the findings: “Our research offers the most extensive evidence to date that there is a significant association between the consumption of processed and unprocessed red meat and the elevated risk of future type 2 diabetes. This supports dietary recommendations to limit intake of these types of meat to mitigate the prevalence of diabetes in the population.”
Professor Forouhi noted that while the evidence connecting poultry consumption with type 2 diabetes is more substantial than previously known, the relationship is still unclear and requires further investigation.
The InterConnect project facilitates the analysis of individual participant data from a variety of studies rather than relying solely on published results. This approach allowed the researchers to include 31 studies in their analysis, including 18 studies whose findings on meat consumption and type 2 diabetes had not been previously published. By incorporating these unpublished studies, the researchers were able to broaden the evidence base and reduce the potential for bias by excluding existing research.
Dr Chunxiao Li, lead author and also from the MRC Epidemiology Unit, explained the advantages of their methodology: “Unlike previous meta-analyses that pooled already published results, our analysis involved data from individual participants across studies. This allowed us to harmonise critical data like meat consumption and the onset of type 2 diabetes, and more accurately account for various factors, such as lifestyle and health behaviours, that could influence the meat consumption-diabetes link.”
Professor Nick Wareham, Director of the MRC Epidemiology Unit and another senior author on the paper, elaborated on the impact of the InterConnect project: “It enables us to study risk factors for obesity and type 2 diabetes across diverse populations worldwide, helping to include demographic groups often under-represented in traditional meta-analyses.” This global perspective is crucial for developing practical health guidelines tailored to different populations and dietary habits worldwide.
More information: Chunxiao Li et al, Meat consumption and incident type 2 diabetes: an individual-participant federated meta-analysis of 1·97 million adults with 100 000 incident cases from 31 cohorts in 20 countries, The Lancet Diabetes & Endocrinology. DOI: 10.1016/S2213-8587(24)00179-7
Journal information: The Lancet Diabetes & Endocrinology Provided by University of Cambridge
