A Mediterranean diet improves glycation markers in healthy people and in those with chronic diseases: a systematic review of clinical trials.

CONTEXT:Consumption of the Mediterranean diet (MedDiet) has beneficial effects on cardiometabolic health and aging. OBJECTIVE:This systematic review aimed to critically investigate the effect of the MedDiet on glycation markers in healthy or overweight individuals with type 2 diabetes or cardiovascular disease. DATA SOURCES:MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched, using the terms "Mediterranean diet" AND "glycation end products, advanced". DATA EXTRACTION:Three randomized and 3 nonrandomized clinical trials, containing data on 2935 adult and elderly individuals with normal weight or overweight, were included. All extracted data were compiled, compared, and critically analyzed. DATA ANALYSIS:The authors of most of the studies demonstrated a reduction in serum concentrations of advanced glycation end products (AGEs), such as εN-carboxymethyllysine and methylglyoxal, and in skin autofluorescence levels after at least 4 weeks of adherence to the MedDiet. The MedDiet also led to positive effects on gene expression of receptors for AGEs, as RAGE and AGER1, and an enzyme involved in detoxification (glyoxalase I). There is no evidence that short-term adherence affects glycation markers. CONCLUSIONS:Glycation markers improved in response to the MedDiet. The possible mechanisms involved may be related to the low AGE and refined sugars content of the diet, as well as its high monounsaturated fatty acid, phenolic compound, and dietary fiber contents. SYSTEMATIC REVIEW REGISTRATION:PROSPERO registration no. CRD42021284006.