Red and processed meat consumption associated with higher type 2 diabetes risk, study of two million people finds

Meat consumption, particularly consumption of processed meat and unprocessed red meat, is associated with a higher type 2 diabetes risk, an analysis of data from 1.97 million participants, published today in The Lancet Diabetes and Endocrinology, has found.

Global meat production has increased rapidly in recent decades and meat consumption exceeds dietary guidelines in many countries.  Earlier research indicated that higher intakes of processed meat and unprocessed red meat are associated with an elevated risk of type 2 diabetes, but the results have been variable and not conclusive.

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

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

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

Habitual consumption of 100 grams of poultry a day was associated with an 8% higher risk, but when further analyses were conducted to test the findings under different scenarios the association for poultry consumption became weaker, whereas the associations with type 2 diabetes for each of processed meat and unprocessed meat persisted.

Professor Nita Forouhi of the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, and a senior author on the paper, said:

“Our research provides the most comprehensive evidence to date of an association between eating processed meat and unprocessed red meat and a higher future risk of type 2 diabetes. It supports recommendations to limit the consumption of processed meat and unprocessed red meat to reduce type 2 diabetes cases in the population.

While our findings provide more comprehensive evidence on the association between poultry consumption and type 2 diabetes than was previously available, the link remains uncertain and needs to be investigated further.”

InterConnect uses an approach that allows researchers to analyse individual participant data from diverse studies, rather than being limited to published results. This enabled 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 study data the authors considerably expanded the evidence base and reduced the potential for bias from the exclusion of existing research.

Lead author Dr Chunxiao Li, also of the MRC Epidemiology Unit, said:

“Previous meta-analysis involved pooling together of 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 study. This meant that we could harmonise the key data collected across studies, such as the meat intake information and the development of type 2 diabetes.

Using harmonised data also meant we could more easily account for different factors, such as lifestyle or health behaviours, that may affect 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 enables us to study the risk factors for obesity and type 2 diabetes across populations in many different countries and continents around the world, helping to include populations that are under-represented in traditional meta-analyses.

Most research studies on meat and type 2 diabetes have been conducted in USA 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.

Using harmonised data and unified analytic methods across nearly 2 million participants allowed us to provide more concrete evidence of the link between consumption of different types of meat and type 2 diabetes than was previously possible.”

InterConnect was initially funded by the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 602068.

Reference

Li, C et al. Meat consumption and incident type 2 diabetes: a federated meta-analysis of 1·97 million adults with 100,000 incident cases from 31 cohorts in 20 countries. Lancet Diabetes Endocrinol.; 20 August 2024. DOI:10.1016/S2213-8587(24)00179-7

ENDS

About the University of Cambridge

The University of Cambridge is one of the world’s leading universities, with a rich history of radical thinking dating back to 1209. Its mission is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence.

The University comprises 31 autonomous Colleges and over 100 departments, faculties and institutions. Its 24,000 students include around 9,000 international students from 147 countries. In 2023, 73% of its new undergraduate students were from state schools and more than 25% from economically disadvantaged backgrounds.

Cambridge research spans almost every discipline, from science, technology, engineering and medicine through to the arts, humanities and social sciences, with multi-disciplinary teams working to address major global challenges. In the Times Higher Education’s rankings based on the UK Research Excellence Framework, the University was rated as the highest scoring institution covering all the major disciplines.

A 2023 report found that the University contributes nearly £30 billion to the UK economy annually and supports more than 86,000 jobs across the UK, including 52,000 in the East of England. For every £1 the University spends, it creates £11.70 of economic impact, and for every £1 million of publicly-funded research income it receives, it generates £12.65 million in economic impact across the UK.

The University sits at the heart of the ‘Cambridge cluster’, in which more than 5,000 knowledge-intensive firms employ more than 71,000 people and generate £21 billion in turnover. Cambridge has the highest number of patent applications per 100,000 residents in the UK.

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About the MRC Epidemiology Unit

The MRC Epidemiology Unit is a department at the University of Cambridge. It is working to improve the health of people in the UK and around the world.  Obesity, type 2 diabetes and related metabolic disorders present a major and growing global public health challenge. These disorders result from a complex interplay between genetic, developmental, behavioural and environmental factors that operate throughout life. The mission of the Unit is to investigate the individual and combined effects of these factors and to develop and evaluate strategies to prevent these diseases and their consequences. www.mrc-epid.cam.ac.uk

About the Medical Research Council

The Medical Research Council is at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers’ money in some of the best medical research in the world across every area of health. Thirty-three MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed. Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. The Medical Research Council is part of UK Research and Innovation. https://mrc.ukri.org/