What do wrinkles and increased risk of chronic disease have in common? They’re both things that many people assume are an inevitable part of aging, and they are both caused—in part—by advanced glycation end products (AGEs). In the book “Dr. Vlassara’s AGE-Less Diet,” co-author Helen Vlassara, MD, one of the scientists who originally identified AGEs, says that AGEs are “intertwined with virtually every aspect of chronic disease and aging.”
AGEs are compounds that form when sugar (glucose) attaches to proteins or certain types of fat. This attachment is called “glycation” and the eventual “end product” is a protein or fat that, instead of acting normally, becomes damaging to health. While some AGEs form in our body as a part of normal metabolism, most of them enter our body through food.
“AGEs have been shown to induce oxidative stress and inflammation, which are both implicated in increasing the risks for diabetes, Alzheimer’s, and cardiovascular disease,” says Mary Purdy, MS, RDN, a Seattle-based registered dietitian nutritionist and adjunct nutrition professor at Bastyr University. “Luckily, there are some simple solutions to help reduce exposure.”
A Guide to Low-AGE Foods
Highly processed, commercially prepared foods are often high in AGEs, but here are some other tips for picking low-AGE foods:
Proteins. Eggs and pulses (beans and lentils) are best, followed by fish, then poultry and pork. Beef is highest in AGEs.
Fats and Oils. Raw nuts and seeds, avocados, and extra-virgin olive oil are best. Store oils properly (in the refrigerator or at least in a dark, cool location) and buy only the amount you can use up quickly to prevent oxidation, which increases AGEs.
Fruits and Vegetables. Fruits and vegetables are naturally low in AGEs, even when you grill, broil, or roast them.
Grains. Boiled or steamed grains are naturally low-AGE, but breakfast cereals, crackers, and cookies are higher because of the heat and dehydration involved in processing.
Dairy. Milk and yogurt—from nonfat to full-fat—are low in AGEs. Cheese has more AGEs, especially aged and pasteurized cheeses.
AGEs and Health. The acronym is oddly appropriate, because AGEs are linked to accelerated aging. AGEs act like glue to bind proteins together, contributing to stiff joints, as with osteoarthritis, or narrowing of blood vessels. They can also cause oxidation (think of how rust forms) in the body and over-stimulate the immune system, contributing to autoimmune diseases. One of the biggest concerns about AGEs is that they tend to accumulate in people with diabetes because high blood sugar levels cause more AGEs to form. Thus, they accelerate the development of diabetes complications, like nerve and blood vessel damage. As we absorb AGEs from food, they accumulate over time, because the body only eliminates about one-third of them. Fortunately, research shows that reducing AGEs in our diet significantly reduces AGEs in our bodies, helping to reduce inflammation and chronic disease.
Reducing AGEs. The three main ways to reduce AGEs in the diet are to choose low-AGE foods, favor cooking methods that produce fewer AGEs, and add ingredients that inhibit AGE formation. Some foods, especially plant foods, are naturally lower in AGEs than others (see A Guide to Low-AGE Foods), but changing the way you prepare food is the most important tool for reducing AGEs.
When you cook meat and other protein-rich foods using dry, high-heat, cooking methods (grilling, broiling, roasting, frying, searing, and sautéing) AGEs can form. These cooking methods cause the food to brown (a process known as the Maillard reaction), which presents a culinary conundrum: browning makes food taste better, but also creates AGEs.
“I encourage either reducing the cooking temperature or cooking time, or using more moist cooking methods, like poaching, braising and simmering,” Purdy says. Slow, low-heat, moist cooking methods, which also include stewing, steaming, using a pressure cooker or slow cooker, or cooking en papillotte (in parchment or foil packets) produces few AGEs.
Reducing cooking time when using high-heat cooking methods also reduces AGEs, because the longer the food cooks the browner it gets. Use small pieces of meat or poultry on a skewer or sauté pan and cook meat and poultry just to the recommended safe minimum temperature—rare or medium-rare steaks have fewer AGEs than well-done.
“For folks who are die-hard grillers, I recommend marinating the meat in an acidic base like lemon juice or vinegar, or using herbs like oregano and rosemary, all of which help to mitigate the production of AGE’s,” Purdy says. She also recommends adding more fruits and vegetables. “Not only are they low in AGEs but they contain antioxidants, which may counteract the harmful effects.”
Whether making your own marinade or purchasing a bottled marinade, go for low-sugar, low-oil versions. You can also use acidic ingredients to further reduce AGEs in moist cooking methods, such as wine or tomatoes in soups, stews or braises, or lemon juice in poaching liquid.
—Carrie Dennett, MPH, RDN