COOKING FOODS, ESPECIALLY MEAT, AT HIGH TEMPERATURES INCREASES RISK OF ALZHEIMER’S & DIABETES

Cooking foods at high temperatures, especially meats and other proteins, alters their composition creating harmful substances that are combinations of sugars and proteins and other large molecules called advanced glycation end products (AGE).  AGE's are naturally produced in the body but when foods rich in AGE's are consumed, the body cannot effectively process them and they can build up over time.  Recent studies add to a growing body of evidence linking greater intake of AGE's with higher levels of chronic systemic inflammation and higher rates of diseases linked with inflammation including heart disease, diabetes, and Alzheimer's.  

In one recent study researchers analyzed food intake records from large studies in the U.S. and France.  From this data, researchers estimated the average AGE content of different diets.  They found a strong link between higher intakes of AGE's and rates of Alzheimer's.  Researchers previously have linked AGEs with Alzheimer’s, and have suggested that these compounds could be one possible cause of the accumulation of amyloid plaques in the brain associated with the disease.

Another recent series of studies found a direct relationship between AGE consumption and insulin resistance.  Insulin resistance, the hallmark metabolic problem that precedes the development of full-blown type 2 diabetes, occurs when the body's cells fail to respond to insulin causing blood sugar to remain elevated.  Researchers randomized diabetes patients to follow either a carb-controlled diabetes diet, that was either high in AGE's or low in AGE's.  Interestingly, researchers found that insulin resistance significantly improved in those on the low-AGE diet but not in those on the high AGE diet.  

What to do:  Aim to reduce your intake of AGE's. AGEs are particularly high in animal-derived foods, especially fatty cuts of red meat,that are cooked at high temperatures.  They are also present in anything that has been charred  or browned such as burnt toast or roasted nuts as well as food items that have been aged such as hard cheeses.   Instead of meats opt for leaner protein sources such as seafood, skinless chicken, lowfat dairy, eggs, and beans.  Instead of high heat cooking methods such as frying, roasting, broiling, and grilling use moist heat methods such as boiling, steaming, poaching, and microwaving.  When grilling, you can reduce the production of AGE's by pre-cooking in the microwave and finishing foods on the grill.  Marinating foods in an acid such as lemon also helps to reduce AGE formation during the cooking process.

Sources:

Perrone L, Grant WB, et al. Observational and ecological studies of dietary advanced glycation end products in national diets and Alzheimer’s disease incidence and prevalence.  Journal of Alzheimer’s Disease. February 2015; 45(3).  DOI:10.3233/JAD-140720

Mark AB, Poulsen MW, et al.  Consumption of a diet low in advanced glycation end products for 4 weeks improves insulin sensitivity in overweight women.  Diabetes Care. January 2014; 37:1 88-95.  DOI:10.2337/dc13-0842.

Uribarri J, Woodruff S, et al. Advanced glycation end products in foods and a practical guide to their reduction in the diet. Journal of the American Dietetic Association. June 2010;110:911-916.  DOI:  10.1016/j.jada.2010.03.018

Adapted from articles available at:

http://www.todaysdietitian.com/newarchives/030314p10.shtml

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3704564/

http://www.cevk.com/high-temperature-cooking-may-increase-alzheimers-risk-2/

http://www.foodnavigator.com/Science/Crusty-AGE-rich-foods-may-raise-risk-of-heart-disease

http://www.sciencedaily.com/releases/2015/02/150203094144.htm