Several studies have already been pointing out in recent times that a diet rich in ultra-processed foods is not very healthy. But now, a group of researchers has carried out a review of 45 different pooled meta-analyses of 14 articles, which associated ultra-processed foods with adverse health outcomes, and have concluded that a diet rich in these types of foods is associated with an increased risk of 32 harmful health outcomes, including cancer, serious heart and lung conditions, mental health disorders, and premature death. The review, published in the journal BMJ and which covers (grouping all studies) almost 10 million participants, becoming the largest ever carried out in this matter, highlights among other aspects that this type of diet increases the risk by up to 22%. of suffering from depression.
Ultra-processed foods, such as sweetened or salty snacks, soft drinks, instant noodles, meat products, pre-prepared pizzas and pasta dishes, cookies and confectionery products, are made by assembling food substances, mostly basic ingredients, and cosmetic additives. (aromas, colorants and emulsifiers) thanks to industrial processes. These types of foods are usually high in sugar, fat and salt, and are low in vitamins, protein and fiber.
However, it can represent up to 58% of total daily energy intake in some rich countries such as the United States – Spain is above 20% – and has increased rapidly in countries of various levels of economic development, but especially in many densely populated nations. low- and middle-income populations.
The researchers – experts from several leading institutions, such as the Bloomberg School of Public Health at Johns Hopkins University in the US or the Sorbonne in France – rated the evidence as convincing, highly suggestive, suggestive, weak or no evidence. They also assessed the quality of the evidence as high, moderate, low or very low.
Overall, the results show that greater exposure to these foods is consistently associated with an increased risk of 32 adverse health outcomes.
Compelling evidence showed that higher intakes of ultra-processed foods were associated with a 50% increased risk of cardiovascular disease-related death, a 48% to 53% increased risk of anxiety and common mental disorders, and a 12% increased risk of type 2 diabetes. .
Highly suggestive evidence also indicated that higher consumption of these products is linked to a 21% higher risk of death from any cause, between 40% and 66% of death related to heart disease, obesity, type 2 diabetes and sleep, and a 22% higher risk of depression.
“This study is very powerful and reaffirms that excessive consumption of ultra-processed foods increases the risk of certain pathologies,” explains Elena Roura, scientific director of the Fundació Alícia. “The evidence is very clear, something that nutritionists, dieticians and other health specialists have been saying, and that is why we have to be very aware,” she adds.
A similar opinion is expressed by Juan Revenga, dietitian-nutritionist. “It's raining on wet. "We already knew it, and now we have more compelling evidence, although it should be taken into account that it is an observational study, in which a cause-effect cannot be established." This aspect is also highlighted by Joana Guarch, a clinical psychologist at the Clínic hospital, who emphasizes, however, that this does not mean “that the methodology used is incorrect.”
The increased risk (22%) of suffering from depression if a diet rich in this type of product is followed is striking. For Roura, “the relationship is not so clear” in this specific section. He explains that when we are depressed or anxious we turn to ultra-processed foods because in the short term, being rich in sugar, they give you pleasure, generating serotonin. “In the end, you don't know if you are depressed because you eat poorly, or you eat poorly because you are depressed.” Guarch sees it the same way. “Is the risk in this type of diet, or does suffering from depression increase the risk of you consuming ultra-processed foods?” he asks.
The microbiota is a different thing, adds Roura. “More and more is known about the relationship between the brain and the microbiota: how you feed it has an impact on your emotions and well-being. Ultra-processed foods are not a product to feed them correctly, because they do not have the fiber, polyphenols, or polyunsaturated fatty acids that they need. Your microbiota is impoverished and that has an effect on your central nervous system.”
