You eat salads, a little fish, you pay attention to sugar… and yet your mind stops at the 11 a.m. meeting. A new study of 2,192 Australian adults aged 40 to 70 shows that adding a simple industrial snack every day is enough to reduce attention span and increase the future risk of dementia. In question: the ultra-processed foods.
This research carried out by Monash University, the University of São Paulo and Deakin University forms the first major signal that the overall quality of the diet is not enough to protect the brain. Even when the diet looks like a Mediterranean dietthese industrial products eat into the ability to concentrate. In other words, the lunch salad does not “erase” the bag of chips.
How ultra-processed foods cause concentration to drop
The scientists of Healthy Brain Project measured attention and processing speed using standardized online cognitive tests. On average, participants got 41% of their calories from ultra-processed foods, close to the Australian average. “To put our results into perspective, a 10% increase in ultra-processed foods is equivalent to adding a standard packet of chips to your daily diet.” said Dr Barbara Cardoso, from the Department of Nutrition, Dietetics and Food and the Victorian Heart Institute at Monash University.
The team observed that for every +10% of calories from these products, the attention score dropped by 0.05 points and a modifiable dementia risk score increased by 0.24 points. “For every 10% increase in ultra-processed foods a person consumed, we saw a clear, measurable decline in their ability to concentrate“, added Dr. Cardoso. Memory was not directly affected, but attention is the basis of learning, decision-making and sustained intellectual work.
Even with a Mediterranean diet, ultra-processing remains toxic
Key point of the study: the associations remain present even after taking into account overall diet quality, including adherence to the Mediterranean diet. In other words, lots of vegetables and olive oil don’t make up for too much processed food. “Ultra-processing of foods often destroys their natural structure and introduces potentially harmful substances such as artificial additives or processing chemicals“explained Dr. Cardoso.
The researchers point out that the
ultra-processed foodsdefined by the Nova system, are industrial formulations based on refined ingredients and cosmetic additives. Sodas, biscuits, sweet dairy desserts, prepared meals, nuggets or very elaborate cereal bars are some of them. In countries like the United States and the United Kingdom, they already represent more than half of energy intake, and are linked to more than 30 health problems, from cardiovascular diseases to type 2 diabetes.
How to reduce ultra-processed foods without disrupting your entire diet
Data from Monash University shows that a simple packet of crisps or a daily sugary drink can be enough to swing attention scores. A realistic objective therefore consists of reducing the proportion of ultra-processed foods by at least 10%, by replacing, one by one, these products: water or infusion instead of soda, natural yogurt and fruit rather than a flavored dairy dessert, a handful of nuts rather than industrial biscuits.
Reading the list of ingredients also helps: a long column of technical names (emulsifiers, colors, flavors, E-, etc.) often indicates an ultra-processed product. Conversely, a food with a few simple ingredients that you could have at home generally remains a better ally for
concentration. The study is cross-sectional, so it doesn’t yet prove causality, but it does show that when it comes to the brain, how food is made matters as much as what we eat overall.