Advanced glycation end products (AGEs) are highly reactive compounds that result from a chemical reaction between reducing sugars and amino acids (also known as a Maillard reaction) and from the oxidation of sugars, lipids, and amino acids. Although the formation of AGEs within the body is a part of normal metabolism, a growing body of evidence suggests that excessive AGE levels promote oxidative stress and inflammation and may therefore increase the risk of developing type 2 diabetes, cardiovascular disease, fatty liver, cancer, Alzheimer’s disease, and infertility.
AGEs were first recognized as being produced within the body under conditions of increased oxidative stress. However, it is now known that dietary AGEs are important contributors to the body’s total AGE concentration, where they become indistinguishable from those AGEs produced within the body itself. The most widely studied AGE is carboxymethyllysine (CML), while another common marker of AGE formation is methyl-glyoxal (MG).
Although the accuracy of AGE measurement is debated within the scientific community, the largest study to date to investigate the AGE content of food showed that AGE content is highly dependent both on the food itself and the preparation method used. Although high fat, high protein foods generally had higher levels of AGEs compared to foods high in carbohydrate, there was considerable variability. By contrast, harsher cooking methods such as frying, broiling, grilling, and roasting consistently led to higher AGE levels than gentler cooking methods such as boiling, poaching, stewing, and steaming, suggesting that high-heat and dry heat cooking lead to higher AGE levels. Some specific levels are shown in Figure 1.
Reference: Uribarri, J, et al. J Am Diet Assoc. 2010 Jun.
A handful of short-term clinical trials have shown that restricting dietary AGEs results in reduced inflammation and increased insulin sensitivity among patients with type 2 diabetes, overweight women, and healthy adults. Moreover, among individuals with obesity and the metabolic syndrome, both dietary and serum AGEs have been significantly correlated with insulin resistance, oxidative stress, and inflammation. However, no long-term trials have been conducted.
The study under review was designed to test whether prolonged (one year) dietary AGE restriction could improve insulin resistance and other risk factors for type 2 diabetes in people with metabolic syndrome.
Advanced glycation end products (AGEs) are produced both within the body and during the cooking and processing of food. Dietary AGEs contribute to the body’s total AGE concentration. Excessive amounts promote oxidative stress and inflammation. Short-term clinical trials show that reducing dietary AGEs improves insulin sensitivity and reduces inflammation. The current study sought to test if these observations would be apparent over the long term (one year).
Other Articles in Issue #24 (October 2016)
Can vitamin D-crease pain?
Pain involves the nervous and immune systems, among others, so it can be tough to address through supplementation. Vitamin D's multitude of roles hint at its possible use as a pain treatment.
Interview: Josh Mitteldorf, PhD
Josh is well-known in the life-extension community, for looking deep into the literature and connecting the dots. We'll get his take on some interesting longevity-related topics. After 30 years wandering in the plasma physics of extragalactic radio sources, Mitteldorf came to the study of aging in 1996 to correct a fundamental error in the foundations of evolutionary theory. After 20 years, the revolution in biological concept of aging that he initiated is only now coming to fruition
When nitrate supplementation doesn’t involve supplements
We've covered several nitrate supplementation studies in previous ERDs. This trial is unique in that it studied the impact of a nitrate-rich diet on exercise performance.
Eat a day, skip a day?
Typical dieting can be a chore. An alternative is to eat less (or not at all) during certain time periods, otherwise known as fasting. This is the first trial to compare regular calorie restriction to alternate-day fasting.
Interview: Courtney Silverthorn, PhD
Are you in the life sciences, but not sure if you want to work in a lab? Courtney is uniquely qualified to give advice about this.
Does being insulin resistant affect weight loss on a low-fat or low-carb diet?
Weight loss is not a simple issue. The impact of a diet could be influenced by whether or not you’re insulin resistant, as examined by this one-year trial of a low-fat versus low-carb diet.
Examining the potential for edible sunscreen
Phytochemicals in plants are well known to have positive effects on chronic conditions, such as heart disease and cancer. But certain ones could also help you avoid ... sunburn.