Ultra-Processed Foods and Dementia Risk

Several large studies have linked eating more ultra-processed foods, such as soda, packaged snacks and processed meats, to a higher risk of dementia and faster cognitive decline. Here's what the research shows, its limits, and simple swaps that fit any budget.

By Jim Pavlish, Editor · Last updated: October 28, 2026 · Editorial policy

"Ultra-processed food" has become one of the most talked-about phrases in nutrition. Several large studies now link eating a lot of it to a higher risk of memory and thinking problems. Here's what the research says, what it can't tell us yet, and practical changes that don't require a complete diet overhaul.

This page is general information, not medical advice. If you have diabetes, kidney disease, swallowing problems or other conditions that affect what you eat, talk with your doctor or a registered dietitian before making big changes.

What counts as "ultra-processed"?

Most researchers use a system called NOVA, which sorts foods by how much they've been processed:

• Unprocessed or minimally processed: fresh or frozen fruits and vegetables, beans, eggs, plain milk and yogurt, fish, nuts, oats, rice.
• Processed culinary ingredients: oils, butter, salt, sugar.
• Processed foods: canned vegetables, cheese, freshly baked bread, canned fish. Usually just a few ingredients.
• Ultra-processed foods: made mostly from industrial ingredients, often with additives you wouldn't use at home, such as flavorings, colorings, emulsifiers and sweeteners. Examples include soda and sweetened drinks, packaged cookies and chips, candy, many breakfast cereals, flavored yogurts, hot dogs and deli meats, chicken nuggets, frozen pizzas and instant noodles.

The categories are not perfect. A whole-grain packaged bread and a frosted snack cake may both count as ultra-processed. Some plant-based meat alternatives fall in this group too, even though they can be part of a healthy diet. That's one reason scientists debate how useful the label is.

What the research shows

UK Biobank, 2022. A study in the journal Neurology followed 72,083 adults aged 55 and older in the United Kingdom for about 10 years. For every 10% increase in the share of the diet made up of ultra-processed foods, the risk of dementia was about 25% higher, after adjusting for age, family history, heart disease and other factors. On average, these foods made up 9% of the diet in the lowest group and 28% in the highest. Drinks were the biggest contributor, followed by sugary products. In the lowest group, 105 of 18,021 people developed dementia; in the highest, 150 of 18,021. The researchers also estimated that swapping 10% of ultra-processed foods for minimally processed ones was linked to a 19% lower risk.

Brazil, 2023. A study of more than 10,000 adults in Brazil, published in JAMA Neurology, found that people who got more than about 20% of their daily calories from ultra-processed foods had a 28% faster decline in overall thinking scores over about eight years than those who ate less. Notably, many participants were middle-aged, which suggests eating habits in midlife may matter.

United States, 2024. Researchers followed 30,239 Black and white US adults aged 45 and older from the REGARDS study for an average of about 11 years and published the results in Neurology. Each 10% increase in ultra-processed foods was linked to a 16% higher risk of cognitive impairment and an 8% higher risk of stroke. Eating more minimally processed foods was linked to lower risk of both. The link held even after the researchers accounted for how closely people followed healthy eating patterns like the MIND diet.

Important limits

• These studies show links, not proof. People who eat more ultra-processed food may differ in many ways, including income, stress, sleep and access to health care. Researchers try to adjust for these, but can't account for everything.
• Diet was often measured only a few times, using questionnaires that rely on memory.
• Dementia was sometimes counted only from hospital and death records, which can miss milder cases.
• No trial has tested whether cutting ultra-processed food prevents dementia.

The National Institute on Aging notes that no specific diet has been proven to prevent Alzheimer's, though healthy eating patterns are linked to better health overall.

Why ultra-processed foods might affect the brain

Scientists have several theories, none proven yet:

• Many of these foods are high in added sugar, salt and unhealthy fats, which can raise blood pressure, blood sugar and weight, all known risk factors for dementia (see Blood Pressure and the Brain and Diabetes and Dementia).
• They're often low in fiber, vitamins and plant compounds found in whole foods.
• They may crowd out foods linked to better brain health, like vegetables, beans, berries and fish.
• Some researchers are studying whether certain additives affect inflammation or gut bacteria. This is still early.

Simple swaps that add up

You don't have to give up every packaged food. The UK study estimated that even swapping about 50 grams a day (roughly a chocolate bar's worth) of ultra-processed food for something minimally processed, like half an apple, was linked to a small reduction in risk. Ideas:

• Drinks first. Since sweetened drinks were the biggest source in the UK study, try water, sparkling water with lemon, unsweetened tea or coffee instead of soda.
• Snacks: a handful of unsalted nuts, fruit, plain yogurt with berries, or raw vegetables with hummus instead of chips or cookies.
• Breakfast: plain oats with fruit instead of sugary cereal.
• Protein: canned beans, eggs, canned or frozen fish, or leftover home-cooked chicken instead of deli meat or hot dogs.
• Frozen and canned produce count. Plain frozen vegetables and fruit, and canned beans or tomatoes, are minimally processed and often cheaper than fresh.
• Read labels. A long ingredient list with words you wouldn't find in a home kitchen is a clue.

For caregivers

If you care for someone with dementia, convenience foods can be a lifesaver, and getting enough calories matters more than perfection, especially if the person is losing weight or has trouble eating. Our guide to Eating, Drinking and Nutrition has tips for mealtimes.

The bottom line

Eating a lot of ultra-processed food is linked to higher dementia risk in several large studies, though cause and effect aren't proven. Shifting some of your diet toward simple, whole foods is a low-risk change that also helps your heart and blood sugar. Pair it with the other steps in Reducing Dementia Risk: The 14 Risk Factors.

Sources

1. Neurology (Li et al., 2022): Association of Ultraprocessed Food Consumption With Risk of Dementia
2. JAMA Neurology (Gonçalves et al., 2023): Association Between Consumption of Ultraprocessed Foods and Cognitive Decline
3. Neurology (Bhave et al., 2024): Associations Between Ultra-Processed Food Consumption and Adverse Brain Health Outcomes
4. National Institute on Aging: What Do We Know About Diet and Prevention of Alzheimer's Disease?
5. Alzheimer's Association: Eat Right

Not medical advice. This article is general information, not a diagnosis or treatment plan for any individual. Talk with a doctor about your situation.

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• The MIND Diet
• Reducing Dementia Risk: The 14 Risk Factors
• Diabetes and Dementia
• Blood Pressure and the Brain
• Eating, Drinking and Nutrition
• How to Read Health Research News