More evidence strengthens link between meat, poultry and T2D

Large data from a federated meta-analysis point to high amounts of red and processed meat and poultry consumption as a risk factor for type 2 diabetes (T2D) in populations globally.

Pooled data from 31 cohorts involving nearly 1.97 million adults showed that eating 50 grams of processed meat daily—equivalent to two or three slices of bacon or a medium-sized sausage—was associated with 15-percent higher risk of incident T2D (hazard ratio [HR], 1.15, 95 percent confidence interval [CI], 1.11–1.20; I²=59 percent). Meanwhile, eating 100 grams of unprocessed red meat daily—equivalent to a small steak or a medium-sized hamburger patty—was associated with a 10-percent risk increase (HR, 1.10, 95 percent CI, 1.06–1.15; I²=61 percent). [Lancet Diabetes Endocrinol 2024;12:619-630]

These positive associations between processed meat and unprocessed red meat and incident T2D were significant in the Americas (HRs, 1.17 and 1.13, respectively), in the European region (HRs, 1.09 and 1.06, respectively), and in the Western Pacific and East Asia region (HRs, 1.15 and 1.17, respectively).

For poultry, daily consumption amount of 100 grams—equivalent to a standard portion size for chicken, turkey, duck, or goose—was associated with an 8-percent higher risk of T2D (HR, 1.08, 95 percent CI, 1.02–1.14; I²=68 percent). This was significant in the European region only (HR, 1.10, 95 percent CI, 1.01–1.21).

“The associations [of each of the three types of meat with T2D] varied across cohorts, but we found no specific factor (ie, age, sex, BMI, number of incident cases, follow-up duration, levels of meat consumption, dietary assessment approach, or geographical location) that could meaningfully account for this heterogeneity,” the investigators noted.

The findings for poultry consumption were weaker than that for unprocessed red meat and processed meat consumption, but still suggested an increase in T2D risk, they added. “Moreover, when replacing processed meat consumption, both unprocessed red meat and poultry consumption were associated with a lower risk of developing T2D.”

In modelled food substitution analyses, replacing 50 g/day of processed meat with 100 g/day of unprocessed red meat or poultry reduced the hazard of T2D by between 7 percent and 10 percent, respectively, on average (HR, 0.93, 95 percent CI, 0.90–0.97 and HR, 0.90, 95 percent CI, 0.82–0.97).

“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 T2D. It supports recommendations to limit the consumption of processed meat and unprocessed red meat to reduce T2D cases in the population,” senior study author Prof Nita Forouhi from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge in Cambridge, UK, stated in a news release.

What’s more is that the study expands upon the limited evidence previously available on the association between poultry intake and T2D, although Forouhi admitted that “the link remains uncertain and needs to be investigated further.”

Global populations

The study included populations from 20 countries that participated in the global InterConnect project, including those from the Americas (n=12) and the Eastern Mediterranean (n=2), European (n=9), Southeast Asia (n=1), and Western Pacific (n=7) regions.

A total of 107,271 incident cases of T2D occurred over a median follow-up of 10 years. Median meat consumption across cohorts was 0–110 g/day for unprocessed red meat, 0–49 g/day for processed meat, and 0–72 g/day for poultry.

“InterConnect enables us to study the risk factors for obesity and T2D across populations in many different countries and continents around the world, helping to include populations that are under-represented in traditional meta-analyses,” noted Prof Nick Wareham, senior study author and Director of the MRC Epidemiology Unit.

“Using harmonized 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 T2D than was previously possible,” Wareham added.

Beyond research on T2D, Forouhi and Wareham, along with colleagues, hope that their study would encourage exploration of sustainable dietary patterns to reduce meat consumption and its effect on other noncommunicable diseases, multimorbidity, and planetary health.