Ultra-Processed Foods Linked with Dementia

Ultra-processed foods are filled with synthetic and industrialized food additives (including endocrine-disrupting chemicals in the packaging) and contain few (if any) natural food ingredients. Highly-processed or ultra-processed “food” items have been linked in scientific studies to numerous health concerns including weight gain, obesity, diabetes, heart disease, strokedepression and frailty and an increased risk of early death. The general consensus among experts is that people should avoid–or greatly minimize–their consumption of ultra-processed foods and replace them with unprocessed and minimally processed foods.

Now, the results of a new study have revealed that people who eat the highest amounts of ultra-processed foods like snack food, junk food (soft drinks, chips, cookies, sausage and other processed meats, deep-fried chicken, yogurt, canned baked beans and canned tomatoes/tomato sauce/paste, ketchup, mayonnaise, packaged guacamole and hummus, packaged breads and flavored cereals, etc.) and fast food may have a higher risk of developing dementia than those who eat the lowest amounts of ultra-processed foods.  Researchers also found that replacing ultra-processed foods in a person’s diet with unprocessed or minimally processed foods was associated with a lower risk.

“Ultra-processed foods…contain food additives or molecules from packaging or produced during heating, all of which have been shown in other studies to have negative effects on thinking and memory skills. Our research not only found that ultra-processed foods are associated with an increased risk of dementia, it found replacing them with healthy options may decrease dementia risk.” -Huiping Li, PhD, researcher, Tianjin Medical University

Study overview

Researchers identified 72,083 people from the UK Biobank, a large database containing the health information of half a million people living in the United Kingdom. Participants were age 55 and older and did not have dementia at the start of the study. They were followed for an average of 10 years. By the end of the study, 518 people were diagnosed with dementia.

During the study, participants filled out at least two questionnaires about what they ate and drank the previous day. Researchers determined how much ultra-processed food people ate by calculating the grams per day and comparing it to the grams per day of other foods to create a percentage of their daily diet. They then divided participants into four equal groups from lowest percentage consumption of ultra-processed foods to highest.

Results overview

On average, ultra-processed foods made up 9% of the daily diet of people in the lowest group, an average of 225 grams per day, compared to 28% for people in the highest group, or an average of 814 grams per day. One serving of items like pizza or fish sticks was equivalent to 150 grams. The main food group contributing to high ultra-processed food intake was beverages, followed by sugary products and ultra-processed dairy.

In the lowest group, 105 of the 18,021 people developed dementia, compared to 150 of the 18,021 people in the highest group.

After adjusting for age, gender, family history of dementia and heart disease and other factors that could affect risk of dementia, researchers found that for every 10% increase in daily intake of ultra-processed foods, people had a 25% higher risk of dementia.

Researchers also used study data to estimate what would happen if a person substituted 10% of ultra-processed foods with unprocessed or minimally processed foods, like fresh fruit, vegetables, legumes, milk and meat. They found that such a substitution was associated with a 19% lower risk of dementia.

Journal Reference: Huiping Li, Shu Li, Hongxi Yang, Yuan Zhang, Shunming Zhang, Yue Ma, Yabing Hou, Xinyu Zhang, Kaijun Niu, Yan Borne, Yaogang Wang. Association of Ultraprocessed Food Consumption With Risk of Dementia A Prospective Cohort. Neurology, July 27, 2022

DOI: 10.1212/WNL.0000000000200871