Consumption of red and processed meat is associated with a higher risk of type 2 diabetes, according to research among 2 million people

Meat consumption, especially consumption of processed meat and unprocessed red meat, is associated with a higher risk of type 2 diabetes, according to an analysis of data from 1.97 million participants published in The Lancet Diabetes & Endocrinologyhas found.

Global meat production has increased rapidly in recent decades and meat consumption exceeds dietary guidelines in many countries. Previous research indicated that higher intake of processed meat and unprocessed red meat is associated with an increased risk of type 2 diabetes, but results were mixed and inconclusive.

Poultry such as chicken, turkey or duck is often considered an alternative to processed meat or unprocessed red meat, but fewer studies have examined the link between poultry consumption and type 2 diabetes.

To determine the link between consumption of processed meat, unprocessed red meat and poultry and type 2 diabetes, the team led by researchers from the University of Cambridge used the global InterConnect project to analyze data from 31 study cohorts in 20 countries. Their comprehensive analysis took into account factors such as age, gender, health-related behavior, energy intake and body mass index.

The researchers found that habitual consumption of 50 grams of processed meat per day – equivalent to two slices of ham – is associated with a 15% higher risk of developing type 2 diabetes over the next ten years. Consuming 100 grams of unprocessed red meat per day – equivalent to a small steak – was associated with a 10% higher risk of type 2 diabetes.

Regular consumption of 100 grams of poultry per day was associated with an 8% higher risk, but when further analyzes were conducted to test the findings under different scenarios, the association for poultry consumption became weaker, while the association with type 2 diabetes for processed meat and unprocessed red meat remained.

Professor Nita Forouhi from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, and senior author of the paper, said: “Our research provides the most comprehensive evidence to date of a link between eating processed meat and unprocessed red meat. and a higher future risk of type 2 diabetes. It supports recommendations to limit consumption of processed meat and unprocessed red meat to reduce cases of type 2 diabetes in the population.

“While our findings provide more extensive evidence on the link between poultry consumption and type 2 diabetes than previously available, the link remains uncertain and requires further investigation.”

InterConnect uses an approach that allows researchers to analyze individual participant data from various studies, rather than limiting themselves to published results.

This allowed the authors to include as many as 31 studies in this analysis, 18 of which had not previously published findings on the link between meat consumption and type 2 diabetes. By including this previously unpublished research data, the authors have significantly expanded the evidence base and the risk of bias due to the exclusion of existing research is reduced.

Lead author Dr. Chunxiao Li, also from the MRC Epidemiology Unit, said: “Previous meta-analysis involved pooling already published results from studies on the link between meat consumption and type 2 diabetes, but our analysis examined data from individual participants in each. This meant that we were able to harmonize the most important data collected in the different studies, such as information on meat intake and the development of type 2 diabetes.

“The use of harmonized data also meant we could more easily take into account different factors, such as lifestyle or health behavior, that may influence the association between meat consumption and diabetes.”

Professor Nick Wareham, Director of the MRC Epidemiology Unit, and a senior author on the paper, said: “InterConnect allows us to study the risk factors for obesity and type 2 diabetes in populations in many different countries and continents around the world, and thereby assist populations underrepresented in traditional meta-analyses.

“Most studies on meat and type 2 diabetes have been conducted in the US and Europe, with some in East Asia. This research included additional studies from the Middle East, Latin America and South Asia, and highlighted the need for investment in research in these regions and in Africa.

“By using harmonized data and uniform analytical methods across nearly 2 million participants, we were able to provide more concrete evidence of the link between consumption of different types of meat and type 2 diabetes than previously possible.”