Another Study Links Highly Processed Foods to Brain Decline

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Woman eating chips
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Tempted to indulge in junk food this holiday season? You probably won’t be doing your brain any favors.

Getting a higher percentage of your calories from highly processed foods is associated with a faster rate of cognitive decline, according to a study recently published in JAMA Neurology, a scientific journal of the American Medical Association.

Researchers in Brazil tracked more than 10,000 people for up to a decade. These participants were ethnically diverse and ranged in age from 35 to 74, with the average age being 51.6.

Participants who got more than 25% of their calories from ultra-processed foods had a rate of cognitive decline that was 28% faster than people who ate the lowest amount of processed foods.

Those in the former group also had a 25% faster rate of executive-function decline. “Executive function” refers to higher-level cognitive skills, such as planning, problem-solving, decision-making and self-control.

The study results send an ominous signal in a country that loves to indulge in processed foods.

About 58% of the calories consumed by U.S. citizens come from ultra-processed foods, the researchers say. People in Great Britain (57%), Canada (48%) and Brazil (30%) also get a lot of their calories from this type of food.

The researchers defined ultra-processed foods as those that contain several processed ingredients (such as table sugar, oils and salt) as well as food additives that are not used in home cooking, such as flavors, colors and emulsifiers.

Examples of ultra-processed foods include:

  • Sweet and savory snacks
  • Breakfast cereals
  • Ice cream
  • Sugar-sweetened beverages
  • Processed meats
  • Ready-to-eat frozen meals

The JAMA Neurology study is not the first to link highly processed foods to cognitive decline. A study published in Neurology, the journal of the American Academy of Neurology, in 2022 found such foods are associated with a greater risk of dementia diagnosis, as we detailed in “This Popular Type of Food Is Linked to Higher Dementia Risk.”

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