Meat Consumption Significantly Raises Type 2 Diabetes Risk

Study: 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. Image Credit: Tatjana Baibakova / Shutterstock.com

A recent Lancet Diabetes and Endocrinologystudy explores how consuming different types of meat may increase the risk of type 2 diabetes (T2D).

Meat consumption and the risk of T2D

Previous studies have reported an increased risk of T2D associated with the consumption of processed meat and unprocessed red meat. However, differences in evidence-grading approaches and interpretation of these studies limit researchers from drawing definitive conclusions on this association. Furthermore, it remains unclear how poultry consumption may affect the risk of T2D.

In addition to the heterogeneity in published findings, geographical imbalances have also been observed, as most studies have been conducted in the United States and Europe. Thus, additional studies in other regions are crucial to understand potential sources of heterogeneity. To date, no study has conducted a meta-analysis of individual participant data to assess the association between T2D risk and meat consumption.

About the study

The hypothesis of the current study was that the consumption of processed meat and unprocessed red meat is associated with a higher incidence of T2D and that this association is absent in the case of poultry consumption. To this end, a federated meta-analysis of harmonized individual-participant data obtained from 31 diverse cohorts within the global Inter Connect project was performed.

Twelve cohorts were from the Americas, two from the Eastern Mediterranean region, nine from Europe, one from Southeast Asia, and seven from the Western Pacific. Eligible participants were 18 years of age or older and provided data on dietary consumption and incident T2D. Any individuals with missing data or who were diagnosed with any type of diabetes were excluded from the analysis.

For each type of meat, hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated at the cohort level. Potential confounding factors, such as body mass index (BMI), were adjusted for in the analysis. To identify potential sources of heterogeneity, a random-effects meta-analysis with meta-regression was conducted.

Study findings

Data were obtained from a total of 1,966,444 individuals. Among the study cohorts considered in this study, six and three were comprised of women and men, respectively.

Among the eligible adults, 107,271 cases of T2D were identified during a median follow-up period of 10 years. Meat consumption varied by population, as individuals residing in European nations reported higher consumption of processed meat than those living in other regions, whereas American cohorts reported greater poultry consumption.

The consumption of unprocessed red meat varied greatly. For example, zero g/day of unprocessed red meat was reported in the Health Effects of Arsenic Longitudinal Study (HEALS) study conducted in Bangladesh, whereas 110 g/day was reported in the Coronary Artery Risk Development in Young Adults (CARDIA) study conducted in the U.S.

A higher intake of processed meat was also observed in German, Puerto Rican, and Iranian cohorts at 49, 28, and eight g/day, respectively. Poultry consumption ranged between zero and 72 g/day in the HEALS and Brazilian Longitudinal Study of Adult Health cohorts, respectively.

High consumption of each type of meat increased the risk of T2D with HRs of 1.10 for every 100 g/day of unprocessed red meat, 1.15 for every 50 g/day of processed meat, and 1.08 for every 100 g/day of poultry. However, as compared to unprocessed red meat and processed meat consumption, the association between poultry consumption and T2D was weaker.

Modeled food substitution analyses revealed that both unprocessed red meat and poultry consumption were associated with a reduced risk of developing T2D. However, this association was not observed for processed meat consumption.

A positive association between meat consumption and T2D was observed in cohorts from North America, European, and Western Pacific regions. The heterogeneity in these associations was not associated with age, sex, or BMI.

Conclusions

The study findings indicate that over a median follow-up period of 10 years, the consumption of processed meat, unprocessed red meat, and poultry increased the risk of T2D throughout various regions in the world. Thus, the positive association between meat consumption and T2D risk should be considered in dietary guidelines to prevent the development of diabetes.

The current findings support the notion that lowering the consumption of unprocessed red meat and processed meat could benefit public health by reducing the incidence of type 2 diabetes.