August 20, 2024

expert reaction to study suggesting association between meat consumption and higher type 2 diabetes risk

A study published in The Lancet Diabetes and Endocrinology looks at meat consumption and type 2 diabetes risk. 

Dr Duane Mellor, Dietitian and Spokesperson for British Dietetic Association; and Honorary Academic Fellow at Aston University, British Dietetic Association (BDA), said:

“This is an interesting analysis, which combines data from many observations from across the world. It used an interesting method to analyse the data, which instead of the normal approach to combine data, it attempted to look at each participant’s data separately. The study found that eating processed meat and red meat was associated with a higher risk of developing type 2 diabetes. Although this study was not able to show a causal link between red meat and processed meat intake and risk of developing type 2 diabetes, only an association with increased risk, there is some plausible biological mechanism which links the haem which is linked to the iron in meat and risk of insulin resistance and other biological markers linked to risk of type 2 diabetes.

“However, although the authors did try to control for other risk factors associated with increased risk of developing type 2 diabetes including having a higher body weight, smoking, alcohol, low vegetable intake. However, due to missing data in the studies the authors were not able to account for the effect of family history, insulin resistance or waist circumference which are more strongly associated with the risk of developing diabetes than many of the risk factors which were accounted for. So, it is possible that the increased risk associated with processed and red meat intake could be a result of these other confounding factors the analysis was not able to take account of.

“The overall message to moderate meat intake is in line with national healthy eating guidelines and advice to reduce risk of developing type 2 diabetes, which include eating a diet which is based on vegetables, fruit, nuts, seeds, beans, peas and lentils along with some wholegrain and moderate amounts of meat and dairy with limited amounts of added fat, salt and sugar. This should be accompanied by regular physical activity to minimise risk of developing type 2 diabetes. If people are considering reducing their meat intake, it is important that the nutrients found in meat are obtained from other foods, these include iron, vitamin B12 and protein. It is important when considering reducing or taking a type of food out of the diet, that any replacement foods provide the same nutrients to maintain a healthy diet overall.”

Prof Naveed Sattar, Professor of Cardiometabolic Medicine/Honorary Consultant, University of Glasgow, said:

“This is an important study which, despite the inevitable observational nature of the evidence, is very well done.  The data suggest cutting red and processed meats from diets may not only protect people from heart disease and stroke but also from type 2 diabetes, a disease on the rise worldwide.  Furthermore, a considerable part of the latter link may be weight gain but other mechanisms may be possible.  Food systems should be adapted accordingly for the benefit of planetary and public health.”

Dr Hilda Mulrooney, Reader in Nutrition & Health, London Metropolitan University, said:

“This is a very large study which included 31 cohorts from 20 countries, and data from 1.97 million adults. It found that greater consumption of all types of meat (unprocessed red, processed and poultry) were associated with increased risk of type 2 diabetes, albeit with variation between the cohorts. Multiple potential confounding factors were adjusted for, and the findings broadly align with other previous smaller studies which also showed increased risk associated with high meat intakes.

“Although it is a very large study which includes previously unpublished data from multiple regions across the world, it cannot demonstrate causality. Nonetheless, the authors suggest a number of possible causal pathways.  Further research is needed to explore the reasons for differences between cohorts including the possible effects of different cooking methods used which can change some of the properties of meat. No effect of BMI was found; a BMI cut-off of 25kg/m2 was used which is appropriate to a Caucasian population but may be less so for other population groups, and this may need further evaluation.

“Meat consumption generally exceeds dietary guidance. Current recommendations are to reduce intakes of red and processed meat and the findings of this study align with those recommendations.  Potential links between poultry intakes and risk of type 2 diabetes remain unclear and research to investigate this further is needed. However, replacing red meat and processed meat with poultry resulted in a lowered risk of developing type 2 diabetes in modelling also carried out by the authors. Current dietary guidance also recommends replacing red and processed meats with meats such as poultry, in addition to reducing overall meat consumption using alternatives such as peas, beans, lentils and tofu.”

‘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’ by Chunxiao Li et al. was be published in The Lancet Diabetes and Endocrinology at 23:30 UK Time on Tuesday 20 August.

DOI: 10.1016/S2213-8587(24)00179-7

Declared interests

Prof Naveed Sattar: No COI

Dr Duane Mellor: I have discussed and been a consultant about the concept of UPF for EUFIC, APPGs (both unpaid as part of my previous academic role) and members of the food industry (including Mars and Danone as a paid independent consultant). I also feel it appropriate to state I follow a vegetarian diet, but support people to follow the dietary pattern of their preference.

For all other experts, no response to our request for DOI’s was received.