A study that followed over 10,000 Brazilians for up to 10 years showed that eating foods like hot dogs and soda for more than 20% of a daily food intake could increase a person's rate of overall cognitive decline. The findings from the study were explained Monday at the 2022 Alzheimer's Association International Conference in San Diego.

"In Brazil, ultra-processed foods make up 25% to 30% of total calorie intake. We have McDonald's, Burger King and we eat a lot of chocolate and white bread. It's not very different, unfortunately, from many other Western countries," said co-author Dr. Claudia Suemoto, an assistant professor in the division of geriatrics at the University of Sao Paulo Medical School.

Signs of cognitive decline can include forgetting dates, conversations, and events. It can also include feeling overwhelmed by decision making or not understanding directions.

"People who consumed more than 20% of daily calories from processed foods had a 28% faster decline in global cognition and a 25% faster decline in executive functioning compared to people who ate less than 20%," said study coauthor Natalia Goncalves, a researcher in the department of pathology at the University of Sao Paulo Medical School.

Eating processed food is known to come with multiple other health risks including an increased risk for cancer, heart disease, high blood pressure, and disbetes. Processed food also lacks nutritional value, according to Laborers Health & Safety Fund of North America.

Half of the participants in the study were college-educated white women and the average age was 51. The study also found that the people who ate the most ultra-processed food were "more likely to be younger, women, white, had higher education and income, and were more likely to have never smoked, and less likely to be current alcohol consumers.”

Researchers noted that preparing one's own food from whole ingredients is the best way to avoid future health issues including cognitive decline.