To obtain the results, nutritionist Arieta Carla Gualandi Leal, responsible for the study, evaluated the diet of 2,572 former students linked to seven universities in Minas Gerais using a standardized questionnaire. These students make up a group that has been monitored by researchers since 2016, every two years. In addition to knowing about consumption, the questionnaire also assesses whether any disease has developed during this biannual period.
The volunteers had to answer a questionnaire about their daily consumption habits of 144 types of food, which were divided into four categories: fresh; cooking ingredients (such as oil, salt and sugar); processed foods; and, lastly, ultra-processed foods. Ultra-processed foods include stuffed cookies, cakes, instant noodles, packaged snacks, soft drinks, among other treats.
According to the nutritionist, the questions included questions about the consumption of a specific food, the frequency (daily, weekly, monthly or annual) and the portion size (small, medium or large). To assist with responses and reduce the possibility of errors, she included a photo album with 96 images to guide respondents. For example, if the person says they eat two spoons of rice a day, the questionnaire illustrates different types of spoons so they can specify the serving size: would it be equivalent to a tablespoon? For dessert? To get rice?
From this collection, the data were tabulated and variables such as gender, age, frequency of physical activity and alcohol consumption were isolated to avoid misinterpretations. The researchers divided the volunteers into groups of low, moderate and high consumption of ultra-processed foods, finding that among those who consumed this group of foods the most daily (between 32% and 72% of daily calories), the risk of developing depression throughout life life was 82%, compared to the group that consumed less ultra-processed products.
The research also found that, among volunteers who consumed more ultra-processed foods daily, the incidence of new diagnosed cases of depression was higher than among those who ate better. “In four years of study, we observed that the prevalence of depression among participants increased by 9.56%. It is a very high rate for a short period of time”, stated the nutritionist.
Multifactorial disease and neuroplasticity
Depression is a multifactorial disease – there is no single cause but a set of associated factors that lead a person to develop it. Among the hypotheses raised by the researcher to justify the findings is the fact that ultra-processed foods are poor in vitamins, minerals, fiber and nutrients that are important for the functioning of the body as a whole. And they are products rich in saturated fats, dyes, chemical additives and other ingredients that are harmful to your health.