Could poaching that chicken breast instead of broiling it help reduce your risk of heart disease and diabetes? Does how you prepare tonights pot roast really affect your arthritis symptoms or the dangerous complications of diabetes? And can opting for a homemade salad rather than a takeout burger and fries actually protect against the effects of aging?Those are among the provocative implications of new research on advanced glycation end products (AGEs), compounds produced when sugars combine with proteins, fats and other ingredients in food. AGEs are formed, for example, in the high-heat browning of foods that makes grilled and seared meats so tasty. Fast-food restaurants and food processors have caught on to this flavor effect and begun adding synthetic AGEs to boost their products appeal to consumers tastebuds. As a result, the AGE content of Americans food has soared over the past half-century, and AGEs have become ubiquitous in the Western diet.The body also produces AGEs naturally as it processes sugars. The slow buildup of these toxic compounds may indeed be part of the aging process: Researchers at Mount Sinai School of Medicine in New York City, in results published in 2007 in The Journal of Gerontology: Medical Sciences, compared AGE levels in two groups totaling 172 adults. Compared to those ages 18 to 45, the group ranging in age from 60 to 80 had 35% higher AGE levels.As AGEs accumulate in the body over time, they promote oxidation and inflammation. Many chronic diseases, including heart disease, diabetes and both osteoarthritis and rheumatoid arthritis, are associated with inflammation. AGEs can be particularly dangerous for diabetics, as the increased availability of glucose in diabetes patients accelerates the formation of AGEs. Studies have shown that AGEs contribute to almost all diabetes complications, such as the risk of vision loss (retinopathy) and peripheral nerve damage (neuropathy).AGEs have also been linked to factors that contribute to heart disease, such as atherosclerosis. The accumulation of AGEs causes blood vessels to stiffen and impairs the function of the cells lining blood-vessel walls. AGEs can modify LDL cholesterol-the bad kind-in a way that makes it more easily oxidized and more readily deposited within blood vessels.How bad are AGEs for your health? Its telling, perhaps, that one well-known source of external AGEs is tobacco smoke. Cigarette smokers have significantly higher levels of LDLlinked AGEs, and diabetic smokers have greater deposits of AGEs in their eyes and arteries.
| Advanced glycation end products (AGEs) are known to increase oxidation and inflammation. Studies have suggested that reducing dietary intake of AGEs can reduce the risk or progression of:
Type 2 (adult) diabetes
Diabetes-related retinopathy (vision loss)
Diabetes-related neuropathy (nerve damage)
Kidney disease Because AGEs are associated with inflammation, they may also be linked to:
Osteoarthritis (the most common form of arthritis)
Rheumatoid arthritis (RA)
Eating Your Age
Until recently, however, it wasnt clear that AGEs in your food could contribute to the buildup of AGEs in your body. But Mount Sinai researchers have shown that about 10% of the AGEs you ingest stick around to promote oxidation and inflammation in your body.In that 2007 study, Helen Vlassara, MD, director of the Division of Diabetes and Aging at Mount Sinai, and colleagues found that age wasnt the only factor in higher AGE levels. Some in the younger group had AGE levels resembling those of senior citizens, as well as elevated amounts of C-reactive protein (a known risk factor for heart disease) and other markers for inflammation. The greater the consumption of food high in AGEs, the higher the levels of AGEs and markers for inflammation in the blood.According to Dr. Vlassara, too much AGEs in the diet can overwhelm your bodys natural ability to remove these toxins, causing AGEs to accumulate in tissues and encouraging inflammation and aging. Dietary intake of AGEs can be especially serious for seniors, since the older you get, the more difficult it becomes for your body to get rid of AGEs.Thats the bad news. The good news is that making a few simple changes in how you prepare your food-along with increasing your consumption of fruits and vegetables, which you already know is a good idea, anyway-can sharply reduce your dietary intake of AGEs.According to a report for the American Diabetic Association authored by Dr. Vlassara and colleagues, Physicians and dieticians can, for instance, advise increased reliance on fresh foods, cooked by brief applications of heat, in the presence of ample water or humidity. A diet designed to be low in AGEs is apparently not lacking in taste, while not requiring compromises in important nutrients. Such a regimen can decrease dietary intake of AGEs by more than 50%, the researchers report, which in turn has been shown to reduce blood levels of AGEs by about 30% within a month.Its not just the calories and saturated fat in these steaks that dictate they should be an occasional indulgence rather than a dinnertime staple: Highheat grilling creates advanced glycation end products (AGEs), compounds linked to aging and chronic disease. (Photo: PGPhoto.org)
| Fighting AGEs in Your Kitchen
You can lower the levels of advanced glycation end products (AGEs) in your diet both by smart food selection and by changing the way you cook. Overall, moving away from the typical Western diet- high in fat, red meat and processed and fast foods-toward a diet focused more on fruits and vegetables, whole grains and lean meats and fish cooked with less browning will not only reduce your AGE intake but help you meet other important nutrition goals as well. Here are some tips to win the battle against AGEs in your own kitchen: Lower cooking temperatures, cooking meats low and slow instead of quickly and at high heat. Opt for steaming, braising and poaching-moist cooking methods that involve liquids-more often instead of grilling, broiling or frying. Be wary of browning. Though browning the sugars and proteins on the surface of foods boosts flavors, these chemical reactions at high temperatures also create AGEs. Cook fresh foods from scratch rather than relying as heavily on processed and packaged foods, which may have added AGEs to enhance flavor or which may have been processed at high temperatures to extend shelf life. Eat more often at home, where you can control how your food is prepared, instead of eating out. Both the cooking techniques and ingredients used at fast-food eateries can dramatically increase your intake of AGEs. Rearrange your typical dinner plate to shrink the portion devoted to meat and increase the allotment of vegetables, fruits and whole grains. Besides being naturally much lower in AGEs, produce also contains nutrients you need plus antioxidants that may help combat some of the oxidative damage from AGEs.
De-AGEing Your Diet
Anew study by researchers from Mount Sinai and the National Institute on Aging, published in the Journal of Clinical Endocrinology and Metabolism, recently put such dietary changes to the test. Dr. Vlassara and colleagues looked at AGEs, diet and health among 325 healthy adults in two age groups, 18 to 45 and 60-plus, and 66 patients with kidney disease. A subset of 40 healthy subjects and nine kidney patients was tested on either a diet designed to reduce AGEs by 30% to 50% or a regular diet with identical calorie and nutrient content.After four months (four weeks for the kidney patients), regardless of age, those on the low-AGE diet saw reduced blood levels of AGEs. Markers of inflammation and blood-vessel health improved by as much as 60%.What is noteworthy about our findings is that reduced AGE consumption proved to be effective in all study participants, including healthy persons and persons who have a chronic condition such as kidney disease, says Dr. Vlassara.AGE levels in the typical Western diet, according to Dr. Vlassara and colleagues, may be as much as triple the safe level for consumption of these compounds. Findings published in 2004 in the Journal of the American Dietetic Association on AGE levels in 250 commonly consumed foods calculated that the average American diet adds up to about 16,000 kilounits of AGEs in a single day. But some foods are much higher in AGEs than others: A 3.5-ounce serving of pizza, for example, totaled 6,825 kilounits, a fast-food hamburger had 4,876 in just 3 ounces, and a broiled hot dog contributed a whopping 10,143.Overall, foods high in fat scored the highest in AGE content, followed by meats. Lower average AGE values were found in foods in the carbohydrate group, with fruits and vegetables at the bottom of the scale. An apple, for instance, scored just 18 kilounits of AGEs.But the way food is prepared affected AGE levels in all categories. Cooking temperature, length of cooking time and presence of moisture were key to the amount of AGEs in foods on the plate. Broiling (about 440 degrees Fahrenheit) and frying (350 degrees) resulted in the highest levels of AGEs, while roasting (350 degrees) and boiling (212 degrees) led to lower levels.That same hot dog (while still not exactly good for you) contained only about two-thirds as much AGEs when boiled for seven minutes instead of broiled for five minutes. Boiling chicken resulted in only about one-fifth the AGEs found in chicken that was broiled. While fast-food French-fried potatoes contained 1,522 kilounits and potato chips packed 3,028 kilounits in 3.5 ounces, the same quantity of baked potato delivered just 218 kilounits.Jaime Uribarri, MD, of Mount Sinais Division of Nephrology, says the research on AGEs doesnt mean you have to swear off grilled steak or fried chicken forever. As with most dietary issues, the key is moderation: Just diminish your exposure, Dr. Uribarri advises.Dr. Vlassara adds, AGEs are ubiquitous and addictive, since they provide flavor to foods. But they can be controlled through simple methods of cooking, such as keeping the heat down and the water content up in food, and by avoiding pre-packaged and fast foods when possible. Doing so reduces AGE levels in the blood and helps the body restore its own defenses.TO LEARN MORE: Journal of Clinical Endocrinology and Metabolism, November 2009; abstract at dx.doi.org/10.1210/jc.2009-0089.