How to Reduce Harmful AGEs in Food
When you stew chicken instead of frying it, you’re cooking up dinner that’s diabetes friendly in ways you’ve probably never realized. Compounds that may be partly responsible for some complications of diabetes have been under the radar—but on your plate. Fortunately, you can slash the amount of them you eat by focusing on healthy food choices and cooking methods.
Scientists are increasingly recognizing that advanced glycation end products (AGEs) are both common in the diet and a likely risk factor for health problems. When consumed, these chemical compounds promote oxidative stress in the body, says Helen Vlassara, MD, director of the Division of Experimental Diabetes and Aging at the Icahn School of Medicine at Mount Sinai in New York and coauthor of The AGE-Less Way: Escape America’s Over-Eating Epidemic. Oxidative stress happens when reactive oxygen, a by-product of normal chemical reactions in the body, builds up and is not removed by protective chemicals called antioxidants. This damages tissues. In high enough levels, AGEs overload the body’s ability to protect itself from oxidants and other harmful substances. This can lead to chronic inflammation (which can lead to blood vessel and other tissue damage), insulin resistance, heart disease, and more.
Where Do AGEs Come From?
AGEs form in food when sugar combines with protein or fat, Vlassara explains. They’re also produced naturally in the body from our own blood glucose. Several studies have shown that people with diabetes and other chronic diseases have higher concentrations of these naturally produced AGEs, says Claudia Luévano-Contreras, PhD, a professor at Universidad Autónoma de San Luis Potosí in Mexico. But Vlassara warns that the ones in the diet may be a bigger worry. Researchers previously believed that dietary AGEs were harmless because they were not absorbed by the body. Today, we know that enough AGEs make their way into the bloodstream to cause concern. Food preparation methods largely determine the amount of AGEs we eat. For example, cooking at high temperatures, especially with dry methods such as broiling or grilling, triggers their production in excess. The golden-brown surface of fried chicken and even the crusty edges of cornbread and lasagna are indications that cooking has increased the amount of these harmful chemicals. AGE levels in many foods have exponentially increased due to the industrial scale of food processing, Vlassara says.
Unfortunately, diabetes, kidney impairment, and aging all hamper the ways the body rids itself of AGEs in the blood. In a study, after people with either type 1 or type 2 diabetes ate a meal that was high in AGEs, researchers found increased signs of inflammation in their bodies. In addition, these compounds may damage the structure and function of some body proteins, says Luévano-Contreras. This can contribute to atherosclerosis, commonly referred to as hardening of the arteries. Luévano-Contreras found that people with diabetes who consumed more dietary AGEs had a higher risk for heart disease. Researchers have also found high levels of AGEs in the nerves of people with diabetes, which may indicate that AGEs play a role in the development of diabetic neuropathy (nerve disease).
For most people, restricting dietary AGEs by about half reduces the body’s load to a level that it can safely handle and eliminate, says nutrition consultant Sandra Woodruff, MS, RD, LDN, coauthor of The AGE-Less Way. In one small study, 26 people with type 2 diabetes were told to prepare their foods as usual or were given instructions to reduce dietary AGEs over six weeks. The group restricting AGEs lowered intake by 44 percent and showed indications of reduced inflammation and oxidative stress. In another study, which lasted four months, Vlassara and her team compared two groups of overweight people with diabetes. One group of six people ate a usual diet. The other group of 12 people ate their usual diet but prepared foods in ways to reduce AGEs. Participants who altered their food prep methods had reduced markers of inflammation and oxidative stress. They also had a 35 percent decrease in their blood insulin levels, which indicates less insulin resistance. Luévano-Contreras points out that only short-term effects have been measured, so it’s impossible to know if the long-term effects of restricting dietary AGEs would be as positive or if other factors caused the results.
Yet reducing dietary AGEs is simple to do, doesn’t cost extra, and fits with the guidelines for managing diabetes. “Foods high in protein and fat—especially of animal origin—and foods cooked and processed with dry heat tend to be the AGE-richest foods,” says Woodruff. Eating more fish, legumes, low-fat milk products, vegetables, fruits, and whole grains and eating less solid fats, fatty meats, full-fat dairy products, added sugars, and processed foods can help reduce dietary AGEs.