OBJECTIVE High-heat cooking of food induces the formation of advanced glycation end products (AGEs), which are thought to impair glucose metabolism in type 2 diabetic patients. High intake of fructose might additionally affect endogenous formation of AGEs. This parallel intervention study investigated whether the addition of fructose or cooking methods influencing the AGE content of food affect insulin sensitivity in overweight individuals. RESEARCH DESIGN AND METHODS Seventy-four overweight women were randomized to follow either a high- or low-AGE diet for 4 weeks, together with consumption of either fructose or glucose drinks. Glucose and insulin concentrations-after fasting and 2 h after an oral glucose tolerance test-were measured before and after the intervention. Homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity index were calculated. Dietary and urinary AGE concentrations were measured (liquid chromatography tandem mass spectrometry) to estimate AGE intake and excretion. RESULTS When adjusted for changes in anthropometric measures during the intervention, the low-AGE diet decreased urinary AGEs, fasting insulin concentrations, and HOMA-IR, compared with the high-AGE diet. Addition of fructose did not affect any outcomes. CONCLUSIONS Diets with high AGE content may increase the development of insulin resistance. AGEs can be reduced by modulation of cooking methods but is unaffected by moderate fructose intake.
The present study did not show any pronounced effects of AGEs on appetite and markers of inflammation, but did indicate that AGEs may affect postprandial ghrelin, oxidative stress, and glucose responses.
Dietary advanced glycation end products (AGE) formed during heating of food have gained interest as potential nutritional toxins with adverse effects on inflammation and glucose metabolism. In the present study, we investigated the short-term effects of high and low molecular weight (HMW and LMW) dietary AGE on insulin sensitivity, expression of the receptor for AGE (RAGE), the AGE receptor 1 (AGER1) and TNF-α, F2-isoprostaglandins, body composition and food intake. For 2 weeks, thirty-six Sprague-Dawley rats were fed a diet containing 20 % milk powder with different proportions of this being given as heated milk powder (0, 40 or 100 %), either native (HMW) or hydrolysed (LMW). Gene expression of RAGE and AGER1 in whole blood increased in the group receiving a high AGE LMW diet, which also had the highest urinary excretion of the AGE, methylglyoxal-derived hydroimidazolone 1 (MG-H1). Urinary excretion of N ε -carboxymethyl-lysine increased with increasing proportion of heat-treated milk powder in the HMW and LMW diets but was unrelated to gene expression. There was no difference in insulin sensitivity, F2-isoprostaglandins, food intake, water intake, body weight or body composition between the groups. In conclusion, RAGE and AGER1 expression can be influenced by a high AGE diet after only 2 weeks in proportion to MG-H1 excretion. No other short-term effects were observed.
We have efficiently synthesized 36 arylopeptoid dimers with ortho‐, meta‐, and para‐substituted aromatic backbones and tert‐butyl or phenyl side chains. The dimers were synthesized by using a “submonomer method” on solid phase, by applying a simplified common set of reaction conditions. X‐ray crystallographic analysis of two of these dimers disclosed that the tert‐butyl side chain invokes a cis amide conformation with a comparatively more closely packed structure of the surrounding aromatic backbone while the phenyl side chain results in a trans amide conformation with a more open, extended structure of the surrounding aromatic backbone.
Advanced glycation end products (AGEs) have been implicated in the pathophysiology of type 2 diabetes and cardiovascular disease. We aimed to determine the associations of urinary carboxymethyl-lysine (CML) and methylglyoxal-hydroimidazolone (MG-H1) levels with cardiometabolic parameters in metabolically healthy obese women. Anthropometric, glycemic, cardiovascular, and urinary AGE parameters were measured in 58 metabolically healthy obese women (age: 39.98 ± 8.72 years; body mass index (BMI): 32.29 ± 4.05 kg/m2). Urinary CML levels were positively associated with BMI (r = 0.29, p = 0.02). After adjustment for age and BMI, there was a trend for positive associations between urinary CML levels and fasting (p = 0.06) and 2 h insulin (p = 0.05) levels, and insulin resistance measured by homeostatic model assessment (HOMA-IR) (p = 0.06). Urinary MG-H1 levels were positively associated with systolic and diastolic blood pressure, pulse pressure, mean arterial pressure, and total and low-density lipoprotein cholesterol after adjustment for age, BMI, and HOMA-IR (all p ˂ 0.05). There were no associations between urinary CML levels and cardiovascular parameters, and between urinary MG-H1 levels and glycemic measurements. Our data support a role of urinary AGEs in the pathophysiology of insulin resistance and cardiovascular disease; however, future studies are highly warranted.
Advanced glycation endproducts (AGEs) are formed when sugars react with peptides and proteins without the help of enzymes and by thermal processing of food such as baking and frying. AGEs and especially N e -(carboxymethyl)lysine (CML) has been used as general key biomarkers for oxidative stress and a number of diseases associated with poor lifestyle. Herein we present the first synthetic pathway to the free zwitter ion of CML via a protected intermediate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.