Meat cooking methods and type 2 diabetes: use of high temperature, open flame for cooking both red meat and chicken associated with increased risk.
According to U.S Dietary guidelines, eating a healthy diet helps majorly with the prevention of chronic diseases. Some of the healthy options for protein intake include seafood, poultry, and lean meats. Studies have found that increased consumption of processed red meat is associated with the risk of type 2 diabetes. However, different cooking methods of meats can play a huge role when it comes to developing type 2 diabetes. Evidence has shown that meat that is cooked at a high temperature can produce hazardous chemicals such as heterocyclic aromatic amines (HAAs), polycyclic aromatic hydrocarbons (PAHs), and advanced glycation end products (AGEs). These chemicals are carcinogens, which can impact inflammation and insulin sensitivity. Levels of these chemicals can be controlled by cooking temperature, duration of cooking, and how well they have been cooked. This large prospective cohort study examined the relationship between open-flame or high-temperature cooking methods for different types of meats, doneness preference (rare, medium, or well-done), and estimated HAA on risk of developing type 2 diabetes.
The data for this study was collected from three prospective cohort studies: the Nurse’s Health Study (NHS), NHS II, and the Health Professionals Follow-up Study (HPFS). A total of 52,752 U.S females, 60,809 U.S females, and 24,679 U.S men were studied from NHS, NHS II and HPFS, respectively. Participants with a diagnosis of diabetes, cardiovascular disease, or cancer at baseline were excluded from the study. Participants were followed up for about 12-16 years and they were given questionnaires to complete. They were asked about the frequency of cooking chicken by pan-frying, broiling, and grilling/barbecuing, the frequency of cooking fish by broiling, and the frequency of cooking hamburger, beef, or steak by pan-frying, roasting, and grilling/barbecuing with seven prespecified response categories (never, less than 1 time/month, 1 time/month, 2-3 times/month, 1 time/week, 2-3 times/week, and 4+ times/week). In addition to this, participants were also asked about the doneness level (lightly browned, medium browned, well browned, and blackened/charred) for different types of meats. Also, dietary HAA intake was calculated by multiplying the frequency of cooking meats with a prespecified HAA levels (ng/g) based on doneness levels.
Results of this study found that higher frequency of high temperature/open flame cooking was associated with higher risk of developing type 2 diabetes. Participants who used more open-flame and/or high-temperature cooking of meats were younger, had higher body mass index (BMI), and alcohol consumption. It was also found that higher frequency of broiling and barbecuing chicken, roasting beef, and grilling/barbecuing steak were associated with a higher risk of type 2 diabetes. Pan-frying of chicken or steak and broiling of fish did not have any impact on type 2 diabetes. Furthermore, a higher doneness level of meat was associated with increased risk of developing type 2 diabetes. Other studies have shown that the meat doneness level, especially if done very well done, could increase the risk of cancers.
This study also found that the higher use of open flame or high-temperature cooking methods for meats was associated with higher weight gain, which itself is a risk for development for type 2 diabetes. Higher intake of HAAs was also associated with increased risk of developing type 2 diabetes. Overall, results of this study conclude that open flame or high-temperature cooking methods should be avoided for both red meat and chicken because such methods can increase the risk of developing type 2 diabetes. The exact mechanism of how it increases the risk of developing type 2 diabetes is unknown. However, some of the factors that could be associated might be the involvement of certain chemicals, including HAAs, PAHs, nitrosamine, and AGEs. These chemicals are produced during the high-temperature cooking of meats and therefore use of higher temperature should be avoided if possible.
One of the strengths of the study includes the involvement of a large sample size and long follow-up period that included a very detailed questionnaire about participants’ different cooking methods. This study also had few limitations. The involved population was mostly Caucasians and therefore, results of this study cannot be generalized to the whole population. More studies need to be performed in order to confirm findings of this study.
- Open flame and high-temperature cooking methods of meat such as grilling/barbecuing contributes to the higher risk of development of type 2 diabetes.
- Higher intake of HAAs was also associated with the increased risk of developing type 2 diabetes.
- Higher doneness level of meat is associated with both the increased risk of developing type 2 diabetes and cancer.
Liu G, Zong G, Wu K et al. Meat cooking methods and risk of type 2 diabetes: results from three prospective cohort studies. Diabetes Care. March 2018.
Vidhi Patel, Pharm. D. Candidate 2018, LECOM School of Pharmacy