People overeat and become overweight for a variety of reasons. The fact that tasty, high-calorie foods are available almost anywhere, anytime, doesn't help. Recently, researchers at the Buck Institute for Research on Aging determined for the first time why certain chemicals in cooked or processed foods, known as
advanced glycation end products (AGEs), increase hunger and seriously challenge people's fixation on these foods.
What are AGEs?
AGEs are metabolic byproducts that occur when sugar binds to a protein, lipid, or part of a nucleic acid. Produced by the famous Melad reaction in the food world, where glycoproteins and heat cause them to brown.
Generally speaking, food that has been cooked, baked, or fried looks delicious, and this is due to the fact that after cooking, baking, or frying, a class of brown compounds, known as AGEs, are produced by the Meladic pronouncement.
Many of today's junk and processed foods have AGEs.
Although the Merad reaction is known for its ability to make food delicious, the resulting chemicals can wreak all kinds of havoc on the body. They cause inflammation and oxidative damage, leading to hardening of the blood vessels, high blood pressure, kidney disease, cancer, and neurological problems.
Not only that, but once AGEs are formed, they cannot be easily detoxified. Instead, the body's ability to remove AGEs gradually decreases with age. So this provides yet another example of the age-related nature of the diseases mentioned above.
And in order to understand the specific effects of AGEs, the researchers specifically used worms, an animal that has a relatively short life cycle, to conduct the tests so that the effects behind them could be more clearly observed.
In the tests, the researchers found that the chemicals, in addition to causing disease and shortening life expectancy, also increased the worms' appetite for the same substances.
Why do AGEs whet the appetite?
To understand why worms' appetites are whetted by AGEs, the researchers purified some well-studied AGEs and found that two of them increased feeding. They further studied one of the compounds to figure out the signaling mechanism.
They showed that food intake was passively increased in mice in the presence of the glod-4 mutation, a mechanism mediated by a specific MG-H1 AGE (methylglyoxal-derived hydroimidazolone-1, a class of AGEs). Further analysis revealed that the GATA transcription factor ELT3 mediates the MG-H1 AGE through a tyramine-dependent pathway to achieve this goal.
This work identifies, for the first time, signaling pathways mediated by specific AGE molecules that enhance feeding and neurodegeneration. They also found that mutant worms that are unable to process naturally produced AGEs have lifespans that are approximately 25–30% shorter. And the work is now being extended to rats, where the researchers want to study the link between AGEs and fat metabolism.
Some simple things anyone can do to lighten the burden of AGEs in the body include eating whole grains (fiber helps keep glucose levels stable), cooking with moist heat rather than drying (i.e., steaming rather than sautéing or baking), and adding acids to foods as they are cooked to slow down the reactions that lead to the formation of AGEs.
