Woman snacking on junk food at her desk

(Photo by juliaap on Shutterstock)

We’ve seen many studies about the ill effects of a diet heavy with processed foods. Research typically points to the terrible effects junk food has on the heart or weight gain. Now, a new study by researchers from Massachusetts General Hospital shows that even consuming a modest amount of processed foods increases the risk of memory problems and stroke.

Ultra-processed foods are food products that have undergone extensive processing and often contain additives to enhance flavor and texture. These foods are typically low in protein, fiber, vitamins, and minerals, and instead loaded with added sugars, sodium and saturated fats. Designed to be convenient, affordable, highly palatable, and have a long shelf life, they’re often the junk food products you’ll find in vending machines and fast-food restaurants.

  • Soft drinks and sugary beverages: Soda, energy drinks, sweetened iced tea, and fruit-flavored drinks
  • Salty and sugary snacks: Potato chips, tortilla chips, cheese puffs, crackers, cookies, cakes and candies
  • Fast food and ready-to-eat meals: Hamburgers, hot dogs, french fries, pizza, and frozen dinners
  • Processed meats: Bacon, sausages, ham, salami and deli meats
  • Packaged bread and baked goods: White bread, sandwich rolls, pastries, and muffins
  • Flavored dairy products: Sweetened yogurts, ice cream, and flavored milk
  • Breakfast cereals: Sugary cereals and granola bars.
  • Reconstituted meat products: Chicken nuggets, fish sticks, and hot dogs
  • Instant soups and sauces: Canned soups, instant soup mixes, ketchup, and mayonnaise
  • Packaged desserts: Puddings, jellies, and sweet pastries

Consuming a diet high in ultra-processed foods has been linked to various health concerns, including obesity, cardiovascular disease, diabetes, and now, as the recent study suggests, potential cognitive decline and increased stroke risk. Led by Dr. W. Taylor Kimberly, the research, published in Neurology, found that:

  • Just a 10% increase in ultra-processed food consumption was associated with a 16% higher risk of cognitive impairment.
  • Greater intake of ultra-processed foods was linked to an 8% increase in stroke risk, with a more pronounced effect among Black participants (15% relative increase in risk).
  • Eating more unprocessed or minimally processed foods was linked with a 12% lower risk of cognitive impairment and a 9% decreased risk of stroke.

Study Methodology

The study followed 30,239 people aged 45 or older who self-identified as Black or White for an average of eleven years. Participants were divided into four groups based on their processed food intake, which was calculated as a percentage of their daily diet. Out of the total participants:

  • 14,175 were evaluated for cognitive decline, with no history of cognitive impairment at the beginning of the study.
  • 20,243 were assessed for stroke risk, with no history of stroke at the beginning of the study.

Researchers adjusted for various risk factors, such as age, sex, and high blood pressure, when analyzing the data.


By the end of the study, 768 people were diagnosed with cognitive impairment, and 1,108 people had experienced a stroke. The results showed that:

  • People who developed memory and thinking problems consumed 25.8% of their diet in ultra-processed foods, compared to 24.6% for those who did not develop cognitive problems.
  • Individuals who had a stroke during the study consumed 25.4% of their diet in ultra-processed foods, compared to 25.1% for those who did not have a stroke.

Discussion and Takeaways

“Our findings show that the degree of food processing plays an important role in overall brain health,” Dr. Kimberly said in a media release. “More research is needed to confirm these results and to better understand which food or processing components contribute most to these effects.”

While the study does not prove a causal relationship between ultra-processed food consumption and cognitive decline or stroke risk, it highlights the potential importance of a healthy diet in maintaining brain health as we age. It’s all the more reason to incorporate more whole foods, like simple cuts of meat, vegetables, and fruits, into your daily diet.

For more research on processed foods published on StudyFinds, click here.

About Steve Fink

Steve Fink is the founder and Editor-In-Chief of StudyFinds.com. He is a veteran journalist who previously served as Vice President of News Engagement for CBS Television Stations' websites. Beginning his career as a sports producer at WJZ-TV in Baltimore in 2001, he previously served as Managing Editor of CBSNewYork.com and WCBSTV.com before joining the company’s corporate digital team in 2010.

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