The sugars and glucose syrup in Halloween candy are far from those found in an apple or in breast milk. But basically, sugar is “everywhere in nature” and it is essential, underlines Stéphanie Fulton, full professor in the nutrition department at the University of Montreal. “In evolutionary terms, our brains were built to search for food and ensure our survival,” she recalls. The brain, in particular, runs on glucose. “It’s a need for the body and several aspects of our biology are there to satisfy this need,” she says.
As soon as it is placed in the mouth, sugar targets receptors located on the tongue and at the top of the mouth. This signal causes the release of dopamine in the brain. “Without dopamine, we would not be motivated to seek out sugar,” summarizes Professor Stéphanie Fulton. The release of dopamine continues during digestion, since the same receptors and transporters are found in the digestive system. “Behavior is further reinforced by the associations we make with sugar: the colors of product packaging, the people we are with, the time of day, holidays…”
When asked why we seek to consume sugar so much, Professor Michel Lucas, from the department of social and preventive medicine at Laval University, offers another angle of analysis. “I think it’s more the sugary products that are coming for us,” he says. In his eyes, Halloween is perpetuated by the world’s big food companies, which flood the market with sugary products, high-calorie drinks and refined cereals. “They make things available and exploit a biological vulnerability,” summarizes the professor, for whom free choice is not really a choice here. “The people who can afford to refute the industrial proposition are often well-heeled and educated people,” he says.
In food, there is a concept called the “ecstasy point”. It is the optimal amount of salt, sugar and fat in a food product to maximize taste. Consumers have integrated these industrial products into their diet and when a habit is formed, they do not tend to change, believes Michel Lucas. “British researchers followed consumers for five years, and they realized that a consumer used to a product that satisfies them does not want to explore elsewhere,” he emphasizes.
Is sugar addictive? The question has been debated in neuroscience since the publication of studies showing that rodents exposed to cocaine and sugar tended to choose sugar first. “Most scientists are not going to consider it an addictive substance, because we need it,” emphasizes Professor Stéphanie Fulton. Still, she says, sugar affects systems and circuits similar to those affected by alcohol or drugs, “but not to the same extent.” People who stop eating added sugar may feel stressed and even shiver a little, but the effect is mostly psychological, says Stephanie Fulton.
Several studies have shown that stress increases the consumption of foods high in sugar and fat; it is therefore possible that these foods attenuate the stress response. Sugar can even have an analgesic effect. In 2016, a Cochrane review concluded that sucrose (table sugar) reduces pain in newborns undergoing punctures or injections. “We don’t yet know the mechanisms very well, but we think that endorphins are synthesized following consumption; the children therefore achieve an effect of ecstasy,” summarizes Professor Michel Lucas.
We are not all equal when it comes to the power of attraction of sugar; we now know that genetics has a role to play. “A small portion of the population is going to have just one gene that increases appetite, but in general, for most people, it’s several genes that make them more likely to overconsume sugar,” explains Stephanie Fulton. According to recent data, these genes are associated with impulsivity and lack of ability to control oneself. »
Even after eating a complete and satisfying meal, we can still feel the urge to dig into our son’s Halloween bag. “We’ve all had the experience of feeling full after a meal, but five minutes later, still opening the dessert menu or the refrigerator door to find ice cream,” emphasizes Stéphanie Fulton. This is also seen in mice in the laboratory; they overconsume sugar water even after having eaten their fill. “We have satiety systems for different tastes,” summarizes Stéphanie Fulton.
