Research

How do ultra-processed foods affect brain health as we age?

New research in the American Journal of Public Health pulls the curtain back on ultra-processed food and helps bring the science into the open.

June 3, 2026
  •  
2 min read
By
Heejin Lee
Cindy W. Leung

A large, nationally representative study of more than 5,000 U.S. adults age 50 and older found that diets higher in ultra-processed foods are linked to a greater risk of cognitive impairment, including dementia.

Following the same individuals over nearly a decade, researchers found that people who ate the most ultra-processed foods were more likely to develop cognitive impairment compared to those who ate the least. In contrast, diets higher in minimally processed foods — like fruits, vegetables, and whole foods — were associated with a lower risk of cognitive impairment.

Certain types of ultra-processed foods, particularly processed meats, were more strongly linked to cognitive impairment.

The takeaway: diets high in ultra-processed foods may not just affect physical health; they may also increase the risk of cognitive decline over time. Choosing more whole and minimally processed foods may help support brain health as we age.

Read the full article published at AJPH

About the author
s
:
Heejin Lee
  
is a postdoctoral researcher at the Harvard T.H. Chan School of Public Health. She received her PhD in Nutrition from Seoul National University. Her research focuses on how diet quality, ultra-processed food consumption, and food insecurity shape cognitive health and aging outcomes, with the aim of identifying factors that support healthy aging.
Cindy W. Leung
  
is an Associate Professor of Public Health Nutrition at the Harvard T.H. Chan School of Public Health. Her research primarily focuses on diet and health disparities, investigating how the experience of food insecurity affects health, chronic disease risk, and the well-being of structurally marginalized populations. Early in her career, she coordinated food distribution programs and taught community nutrition education at a food bank in Oakland, California, which shaped her focus on applied community nutrition.

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