Suiker in perspectief editie 53 | september 2021

DR. PAULINA MORQUECHO CAMPOS ON THE IMPORTANCE OF FOOD ODOURS “The nose knows, but the brain is the one taking the final food choice” |11 Suiker in perspectief, september 2021 “In terms of behaviour, we saw with the participants in our laboratory setting that when they smelled for example meat, they did indeed got more cravings for something savoury”, Paulina tells. “However, contrary to our expectation, they did not actually eat more meat products. Maybe our brain can ignore those signals and determine that the body does not need food at that moment. Yet, with an eye-tracking experiment, we saw that the participants' gaze was immediately drawn to the sweet snacks after they smelled chocolate odour. It would be interesting to see how people react in a real life setting, such as a supermarket or shopping centre.” Smelling is not enough “One of the things we expected to find, was that the amount and composition of the saliva would change if someone smelled a certain food odour”, Paulina continues. “We thought that if someone, for example, smelled bread, the body would anticipate and already start producing the specific enzymes in the saliva that are needed to properly digest bread. Our experiments showed that the participants did indeed produce more saliva after smelling food odours, but that the composition of the saliva did not change. Apparently smell is not a clear enough signal for that.” More information needed “We then conducted an experiment in which participants received a cumulative amount of sensory information about food: first smell, then an image of the food, then taste and finally chewing the food. We found out that the body only starts to produce the right enzymes when the food is actually chewed. Also important, we found that the type of food did not influence the enzyme production, but the cumulative sensory information did.” Disconnected Surprisingly, a similar experiment carried out in the 1990s showed that production of enzymes was different depending on the type of food. “We do not know why this was not the case in our tests”, Paulina responds to this. “Perhaps our bodies have become so ‘disconnected’ from nature that we no longer respond adequately to the odours in our environment. Or we are no longer used to eating just one product at the time, because of the rich range of composed food in our obese society: when do we eat just bread? We only eat bread with toppings, usually different types. Maybe the modern body prefers to wait until it knows for sure what is actually being eaten...”