Boiled or Baked: Method Matters for Pre-Diabetics

Advanced glycation end-products (AGEs) cause insulin resistance

Most people have heard the saying “you are what you eat.” But what about how you cook what you eat? New research suggests that people at risk for diabetes should consider both.

According to a press release issued by Mount Sinai Hospital, a new study found that obese individuals with signs of insulin resistance—a common precursor to diabetes—lowered their risk for diabetes when consuming a diet low in advanced glycation end products (AGEs).

This study builds on a 2014 study, which confirmed that high levels of AGEs can cause pre-diabetes by increasing insulin-resistance.

AGEs are most commonly found in dry heat-cooked or heat-processed foods. According to the American Diabetes Association, foods high in AGEs include red meat and cheese, while foods like chicken and oatmeal tend to be low in AGEs.

However, cooking method can alter the amount of AGEs in a food product. Steaming or boiling foods reduces AGEs, while frying increases them. Fried chicken, for example, has six times the amount of AGEs as boiled chicken.

“While food AGEs are prevalent, particularly in Western diets, our study showed that avoiding foods high in AGEs could actually reverse the damage that had been done,” says lead author Helen Vlassara, MD, in the press release. Dr. Vlassara is a Professor at the Icahn School of Medicine at Mount Sinai. She adds:

“This can provide us with new clinical approaches to pre-diabetes, potentially helping protect certain at-risk individuals from developing full diabetes and its devastating consequences.”

To conduct the study, Dr. Vlassara and her team studied two groups of obese individuals over a one-year period. The first group ate a diet high is AGEs, and the second group ate a diet low in AGEs.  Members in the second group were instructed to avoid grilling, frying of baking their food, instead relying on poaching, stewing, or steaming.

The research team analyzed the participants’ blood and urine samples at the beginning of the trial and compared them to samples taken at the end of the trial. Though insulin resistance was similar for both groups at the beginning of the study, they varied greatly at the end.

The team found that insulin-resistance was significantly improved for the group who ate a diet low in AGEs. Members of that group also decreased their body weight and lowered AGE levels in their bodies.

The participants who ate a diet high in AGEs showed higher levels of AGEs and more markers of insulin resistance at the end of the study.

“Elevated serum AGEs in individuals can be used as a marker to diagnose and treat ‘at risk’ obesity in patients,” says researcher Jaime Uribarri, MD and in the press release. He adds:

“Even without losing a significant amount of weight, a reduced AGE diet can help prevent diabetes in these patients.”

This study was published in Diabetologia. The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health. The authors disclosed no conflicts of interest.

NCBI, “Oral AGE restriction ameliorates insulin resistance in obese individuals with the metabolic syndrome: a randomised controlled trial”

Mount Sinai Hospital, “Diets avoiding dry-cooked foods can protect against diabetes”