People who eat the highest amounts of ultra-processed foods such as soft drinks, chips and cookies may have a higher risk of developing dementia than those who eat the lowest amounts, according to a new study.
Researchers also found that replacing ultra-processed foods in a person’s diet with unprocessed or minimally processed foods was associated a lower risk.
What are ultra-processed foods?
Ultra-processed foods are formulations of substances derived from foods plus numerous additives used to flavour, bleach, colour, emulsify, texturize and preserve. They contain little, if any, real food at all.
These foods are typically high in calories, unhealthy fats, added sugars and sodium and are lacking fibre and protective phytochemicals. The altered taste and texture of ultra-processed foods make them highly palatable and habit-forming.
Examples include protein bars, margarine, frozen pizza, chicken nuggets, breakfast cereals, pretzels, instant noodles, muffin and cake mixes, mass-produced packaged breads, soft drinks ketchup and mayonnaise.
About the study
The 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 ages 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.
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.
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. Such a substitution was associated with a 19% lower risk of dementia.
According to the researchers, “our results also show increasing unprocessed or minimally processed foods by only 50 grams a day, which is equivalent to half an apple, a serving of corn or a bowl of bran cereal, and simultaneously decreasing ultra-processed foods by 50 grams a day, equivalent to a chocolate bar or a serving of fish sticks, is associated with a 3% decreased risk of dementia.” “It’s encouraging to know that small and manageable changes in diet may make a difference in a person’s risk of dementia.”
The study does not prove that ultra-processed foods cause dementia. It shows only an association.
A limitation of the study was that cases of dementia were determined by looking at hospital records and death registries rather than primary care data, so milder cases may have been overlooked.
Source: Neurology, July 27, 2022.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.