Snack Attack

Ultraprocessed foods may speed cognitive decline

Ultraprocessed foods — such as cereal bars, hot dogs and instant noodles — are convenient and taste good, making it easy for busy people to eat on the go. But lurking underneath that colorful packaging are substances that may damage your brain.

According to a study presented at the Alzheimer's Association International Conference® (AAIC®), a diet rich in ultraprocessed foods can be harmful for the aging brain. Researchers Natalia Gomes Gonçalves, Ph.D., and Claudia Suemoto, M.D., Ph.D., of the University of Sao Paulo Medical School in Brazil, looked at the eating habits of nearly 11,000 Brazilian adults and their performance on tests measuring thinking skills over eight years.

The study found that people who consume the highest amount of ultraprocessed foods have a 28% faster decline in cognitive scores, including memory, verbal fluency, and the ability to plan and execute goals, compared to those with a lower consumption of ultraprocessed foods.
 

What are ultraprocessed foods?

Many types of food can be considered processed, such as cheese, pasta sauce and canned vegetables. But food is ultraprocessed when it is packed with additives like fats, sugars, artificial flavors and stabilizers, and has been subjected to multiple processing methods to transform taste, texture or appearance.

Suemoto says that ultraprocessed foods contain little or no whole foods like vegetables, fruits and meat. "Foods in the ultraprocessed category typically include flavorings, colorings, emulsifiers and other cosmetic additives," she says.

Ultraprocessed foods eaten by participants in the study included white bread, cookies, mayonnaise, flavored yogurt, margarine, sausage, hamburgers, ham, salami, hot dogs, instant noodles, candy bars, chocolate, cereal bars, frozen meals and soda. The study found consuming more than 20% of daily calories from ultraprocessed food had an impact on cognition.
 

Making healthier choices

"Eating a variety of fruits and vegetables and decreasing the consumption of foods rich in added fat, sugar and salt can be a powerful strategy to preserve not only brain function but overall health," Gonçalves says.

Where you live, your budget, and access to fresh foods and quality health care can impact your ability to make healthy choices. But for those who are able, some simple changes in what you eat can help reduce risk of cognitive decline, Gonçalves says.

"Cook from scratch at home. Instead of buying a frozen pizza, buy separate fresh ingredients for toppings and make homemade dough," she says. "We need to dedicate a little extra time and energy."
 

Never too late to start

People may benefit from healthier food choices at any age, Gonçalves says. But the study in Brazil found the association between eating ultraprocessed foods and cognitive decline was stronger in middle-aged adults (35-59 years old) compared with older adults (over 59 years old). While it is never too late to adopt healthy habits, people may lower their risk for cognitive decline the sooner they start.

"Middle age is an important period of life to adopt preventive measures since the choices we make at this age may influence our older years," Gonçalves says.
 

Healthy heart, healthy brain

While ultraprocessed food may harm the brain, research has shown that certain diets can help protect it. The Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND diet) has been linked to better cognitive performance and decreased risk of cognitive decline and dementia in several studies across the globe, Suemoto notes. "The healthy foods included in the MIND diet are whole grains, leafy greens and other vegetables, nuts, beans, berries, poultry, fish and olive oil," she says.

Part of following the MIND diet includes limiting the consumption of unhealthy foods like pastries and sweets, fried foods and salt — all foods known to be harmful to vascular health, which in turn could quicken cognitive decline.

In general, what is good for the heart is also good for the brain. The brain is the most highly vascularized organ in the body, says Percy Griffin, Ph.D., M.Sc., director of Scientific Engagement at the Alzheimer's Association.

"The brain is greedy, using up 20% of the body's energy, which we get from food. So it's important to give the brain good, healthy fuel to allow it to work efficiently," Griffin says. "There is growing evidence that what we eat can impact our brains as we age, and many studies suggest it is best for our brain to eat a heart-healthy, balanced diet low in processed foods, and high in whole, nutritional foods like vegetables and fruits."