This 2021 rodent study investigated dietary advanced glycation end products (AGEs):

“There is increasing evidence in humans and animals that consumption of dietary AGEs contribute to AGEs measured in plasma and organs and that a diet high in dietary AGEs in humans has negative biological effects, such as low-grade inflammation, endothelial dysfunction, and insulin resistance. However:

• It is currently unknown whether AGE accumulation in tissues and the negative biological effects associated with a high AGE diet are reversible; and
• How dietary AGEs are involved in the aforementioned biological effects remains poorly understood.

We hypothesized that mice fed a high dietary AGE diet for 10 weeks would show increased blood and tissue AGEs, increased inflammatory markers, and different microbiota composition as compared to mice fed a standard dietary AGE diet. In addition, we studied whether changes following the high dietary AGE diet were reversible by implementing a switch after 5-weeks of high dietary AGE diet to the standard dietary AGE diet for 5 subsequent weeks.

To obtain a high AGE diet, a standard rodent chow was baked at 160 ^◦C for two hours. Free- and protein-bound AGEs Nε-(carboxymethyl)lysine (CML), Nε-(1-carboxyethyl)lysine (CEL), and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were analyzed in plasma, liver, and kidney. Additionally, free-, protein-bound AGEs, and AGE precursor oxoaldehydes methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3DG) were analysed in animal diets.

Inflammatory z-score consists of TNF-α, IFN-γ, KC/GRO, IL-6, and IL-10:

A high AGE-diet led to an increase of AGEs in plasma, kidney, and liver, and to more inflammation, and modification of gut microbiota. These effects were reversed or discontinued by a diet lower in AGEs.

Our observations of reversible AGE accumulation in kidney and liver may not be extrapolated to other organs. Likewise, our findings in mice cannot be directly extrapolated to humans, as species differences exist in for example metabolic rate and dietary habits, as also in gut microbiota composition.”

https://www.sciencedirect.com/science/article/abs/pii/S0963996921004464 “Dietary advanced glycation end products (AGEs) increase their concentration in plasma and tissues, result in inflammation and modulate gut microbial composition in mice; evidence for reversibility” (not freely available)

This study started with 9-week-old mice and lasted eleven weeks, the human equivalents of which are ages 20 to 30 years. Study measurements weren’t intended to detect all potential symptoms of high-AGE diets. The lead author followed up with All about AGEs.

AGEs’ reversibility in older humans is one of my operative hypotheses:

• I haven’t cooked or eaten high AGE precursor or AGEs food at home in the past three years.
• The highest AGE item I’ve eaten at restaurants has been fish tacos.
• I’m not hyperglycemic, and don’t expect that further AGE accumulation from either exogenous or endogenous sources has occurred.