Fragrant and crunchy French fries, inviting donuts and cakes, a nice grilled steak, cola-flavoured sugary drinks, all foods that are not the best for your health but that make your mouth water just imagining them, right? And when you taste them you think you're the one choosing to do it. What if they told you that instead it is these same foods that exercise control and make you want to consume other similar foods, thus increasing the risk of obesity and associated diseases? It may seem strange but this is exactly how things are, as stated by very recent scientific research appearing in the magazine eLife and published by an American team from the University of Arizona (Shanmugam et al, eLife, 2023).
Why we crave unhealthy foods
What makes us want to consume certain foods that are often not even healthy, such as sweets, snacks, grilled meats and fried foods? American researchers carried out a laboratory study on worms. In this way, they were able to answer this question. In particular, scientists' attention has focused on some substances, called advanced glycation end products, which develop in abundance in these foods during cooking processes such as baking, grilling and frying, as well as being present in highly processed foods. These are the substances that, as a result of the Maillard reaction, give the brown color and that irresistible taste to dishes. These substances, however, if on the one hand make foods palatable, on the other hand increase inflammation and the risk of obesity, stiffen the walls of blood vessels, favor the onset, over the years, of hypertension, kidney disease, neurodegeneration and cellular degeneration. But it doesn't end here. In fact, the final products of advanced glycation also have another characteristic. According to the study, it was observed that the intake of these substances caused the worms to prefer other foods similar to those just consumed containing high quantities of advanced glycation end products, with a mechanism that scientists were able to understand. It is precisely the advanced glycation end products that stimulate the action of certain enzymes, which in turn induce appetite and excessive intake of certain foods.
How can we defend ourselves?
The study was carried out on worms but has very important implications for human health, as what was observed also applies to us human beings and our propensity to prefer certain less healthy foods. The process of formation of advanced glycation end products cannot be reversed. For example, once you have toasted white bread for a long time and it is dark, it is not possible to make it go back to the way it was before. So what can we do to protect ourselves from the harmful effects of these substances? Our body is equipped with a protection system but, with age, this mechanism weakens. A good choice is therefore to prevent or at least limit the formation of advanced glycation end products, which, as we have seen, are harmful and encourage the desire to continue eating foods that contain them. For example, you can limit refined grains and choose whole grains, where fiber makes glucose more stable, thus slowing the formation of advanced glycation end products. It is also possible to act on cooking methods, favoring cooking methods with wet heat, such as steaming, while limiting other cooking methods with dry heat such as grilling or frying. In addition, we can add an acidic component, such as lemon juice, during more risky cooking, such as grilling. All these measures limit the formation of the final products of advanced glycation, make dishes healthier and limit the desire to consume other sweets, fried and grilled foods.