Do Ultra-Processed Foods Affect Memory? What the 2026 Research Shows

You've probably heard some version of the same advice: if you care about your brain, eat fewer ultra-processed foods.

It sounds straightforward enough.

But when researchers actually look at ultra-processed food and cognitive performance over time, the answer gets considerably less tidy.

Three recent studies examined the question in thousands of older adults. Two found associations between higher ultra-processed food intake and poorer performance on at least some cognitive measures.

Another followed adults across roughly a decade and found no association with cognitive decline at all.

So are ultra-processed foods actually bad for your memory?

That's a less dramatic answer than you'll find in a lot of headlines.

It's also a much more useful one.

What exactly is an ultra-processed food?

The term doesn't simply mean "food that came in a package."

Researchers commonly use a system called the NOVA classification, which groups foods according to the degree and purpose of industrial processing.

At one end are foods that are unprocessed or minimally processed: fruit, vegetables, eggs, plain grains, meat and similar foods.

At the other are ultra-processed foods, typically industrial formulations made with multiple ingredients and processes that aren't commonly used in a home kitchen.

Obvious examples include many soft drinks, packaged sweets and snack foods.

But the category can also include foods people don't automatically think of as "junk food," such as some breads, breakfast cereals, flavored yogurts, protein bars, sauces and ready-to-eat meals.

That's part of what makes this research complicated.

"Ultra-processed" describes how a food was produced. It doesn't perfectly describe its nutritional value.

Do ultra-processed foods actually affect memory?

That's exactly what several research groups have tried to answer recently.

And their findings don't completely agree.

What did the U.S. study find?

One study published in 2026 analyzed data from 1,408 older U.S. adults participating in the nationally representative Health and Retirement Study.

None of the participants had dementia or reported memory problems at baseline.

Researchers estimated how much of each participant's daily energy intake came from ultra-processed foods and later assessed several separate areas of cognition, including memory, language, orientation, visuospatial ability and executive function.

The average participant got about 42% of daily energy intake from ultra-processed foods.

The clearest signal appeared in executive function—the set of mental skills involved in planning, switching between tasks, organizing information and controlling attention.

People with higher UPF intake showed a possible greater likelihood of executive-function impairment.

But there was an important catch.

The overall trend was only marginally statistically significant, and higher UPF intake was not significantly associated with impairment in memory, language, orientation or visuospatial ability.

So this study did not show that people who ate more ultra-processed foods broadly performed worse across every area of cognition.

It suggested a much narrower possibility: executive function may be one area worth watching.

Then a much larger study found something different

A second 2026 study examined 11,502 Australian adults with an average age of about 78.

Researchers separated participants into those consuming fewer than four servings of ultra-processed food per day and those consuming four or more.

They then followed cognitive performance across a median of approximately 5.6 years.

Higher UPF consumption was associated with somewhat poorer performance on measures of:

• global cognitive function
• verbal fluency
• processing speed
• overall composite cognitive performance

But even here, the results weren't universal.

The researchers did not find a statistically significant difference on their verbal learning and memory test.

And the differences they did identify were relatively small.

So now we have two studies pointing toward a possible cognitive association—although not necessarily toward memory specifically.

Then comes the third study.

Why did a 10-year Dutch study find no association?

Researchers in the Netherlands analyzed 1,371 adults ages 55 and older from the Longitudinal Aging Study Amsterdam.

This study is particularly useful because participants completed cognitive testing repeatedly across roughly a decade.

Researchers measured global cognition, information-processing speed, episodic memory and executive function.

They also classified dietary intake according to the same NOVA system used in much of the ultra-processed food research.

The result?

They found no evidence that total ultra-processed food intake was associated with cognitive function or cognitive decline in any of the domains they measured.

That's not a minor contradiction.

It's exactly why "ultra-processed food damages your brain" is stronger than the current evidence supports.

How can three studies reach different conclusions?

Because they're not actually running the same experiment.

Nutrition research is extraordinarily difficult to isolate.

Consider just a few of the differences:

The participants were different

The U.S., Australian and Dutch populations differed in age, lifestyle, healthcare environment and overall diet.

The amount of ultra-processed food was different

UPFs made up an average of about 42% of daily energy intake in the U.S. study.

In the Dutch study, ultra-processed foods represented an average of about 20% of daily food intake by weight.

Those aren't directly comparable measurements, but they illustrate how different the dietary environments were.

The studies measured food differently

Researchers generally have to estimate long-term diet from questionnaires or dietary surveys.

People don't remember everything they eat perfectly, and diets change over time.

They measured cognition differently

"Cognition" isn't one thing.

Memory, processing speed, attention, verbal fluency and executive function rely on overlapping but distinct systems.

One study can find a difference in executive function while another sees no difference in episodic memory—and both results can be accurate.

This is also why it's useful to be specific when talking about how cognition changes as we get older. A single global label like "brain health" can hide very different processes underneath it.

Does this mean ultra-processed foods are harmless?

No.

A lack of consensus around cognition doesn't mean there are no reasons to pay attention to diet quality.

Ultra-processed-food consumption has been studied in relation to a broad range of health outcomes, and dietary patterns rich in vegetables, fruit, whole grains, legumes, nuts, fish and unsaturated fats continue to have substantial support in general health research.

But that's different from saying:

"Eat this packaged food and your memory will get worse."

The cognitive evidence isn't precise enough to support that statement.

And lumping every ultra-processed food into one category may hide meaningful differences between products.

Is all processed food bad for your brain?

No.

Almost everything we eat has undergone some form of processing.

Frozen vegetables have been processed. Olive oil has been processed. Canned beans have been processed. Yogurt has been processed.

Even the NOVA system distinguishes ordinary processed foods from ultra-processed formulations.

So "processed" should not automatically be treated as another word for unhealthy.

That's also why reading the actual ingredient list and nutrition information can sometimes tell you more about a food than simply knowing which processing category it falls into.

What about the gut-brain connection?

This is one plausible piece of the larger picture, but it shouldn't be used to fill in gaps the human studies haven't answered.

Diet influences the composition and activity of the gut microbiome, and the microbiome communicates with the nervous system through several pathways involving immune signaling, metabolites and the vagus nerve.

We've covered how the gut and brain communicate in more detail, as well as what the clinical research on probiotics and cognition actually shows.

But none of that proves that the cognitive findings in these three UPF studies were caused by changes in gut bacteria.

It's a possible mechanism researchers can investigate—not an explanation we should assume.

What should you actually do with this research?

Probably less than a scary headline would have you believe.

You don't need to walk through your pantry throwing away anything with a barcode.

A more evidence-aligned approach is to focus on the overall pattern.

• Build most meals around minimally processed foods when practical. Vegetables, fruit, whole grains, beans, nuts, eggs, fish and other basic foods give you a strong foundation.
• Don't assume packaged automatically means unhealthy. Look at the actual food rather than making decisions from the processing category alone.
• Pay attention to displacement. A packaged food becomes more relevant when it repeatedly replaces fiber-rich, nutrient-dense foods—not simply because it came from a factory.
• Think in patterns, not isolated meals. Cognitive aging happens over years. One frozen dinner or granola bar isn't the meaningful unit of measurement.
• Keep diet in perspective. Sleep, physical activity, cardiovascular health, stress, social connection and other factors also contribute to healthy cognitive aging.

That's consistent with the broader research we've reviewed on what actually supports memory over time.

The most interesting finding may be that the answer isn't settled

Nutrition headlines tend to reward certainty.

"This food protects your brain."

"That food destroys it."

Actual nutritional science rarely behaves that neatly.

Across three recent studies involving more than 14,000 adults, higher ultra-processed food intake was associated with poorer performance on some cognitive measures in two studies.

The third found no association with cognitive decline across roughly a decade.

That doesn't mean the research tells us nothing.

It tells us something more specific:

Overall diet quality still matters, but we're not yet at the point where the degree of food processing alone can tell us what will happen to someone's memory.

And when new research doesn't fit neatly into the headline we expected, that's usually the part worth paying attention to.

Brain health is bigger than any one input

Diet is one piece of a much larger brain-health picture alongside sleep, movement, stress, social connection and other daily habits.

For people interested in another area of brain-health research, you can also explore BEACON40 and the research behind 40Hz light stimulation.

The 40Hz research is separate from the nutrition studies discussed in this article, and BEACON40 should not be interpreted as a way to counteract the effects of a particular diet or food.

If you'd rather start with the science, we've also broken down what the research on 40Hz light and the brain actually shows.

Frequently asked questions

Do ultra-processed foods cause memory loss?

Current research does not establish that ultra-processed foods cause memory loss. Several observational studies have found associations between higher UPF intake and poorer performance on certain cognitive measures, while other long-term research has found no association with cognitive decline.

Are ultra-processed foods bad for the brain?

Higher ultra-processed-food intake has been associated with some poorer cognitive outcomes, but findings are inconsistent and most available studies are observational. Researchers cannot yet conclude that the processing level itself causes poorer brain health.

What foods count as ultra-processed?

The NOVA classification generally defines ultra-processed foods as industrial formulations made using multiple ingredients, substances or processes not commonly used in home cooking. Examples can include soft drinks, packaged snacks, many sweets, some breakfast cereals, packaged breads, ready meals and certain flavored dairy products.

Is all packaged food ultra-processed?

No. Packaging and processing are not the same thing as ultra-processing. Frozen vegetables, canned beans and many other packaged foods may be minimally processed or processed without meeting the definition of an ultra-processed food.

Do ultra-processed foods cause brain fog?

There isn't strong evidence showing that eating a particular ultra-processed food directly causes brain fog. Diet can influence factors such as energy regulation and overall health, but brain fog has many possible contributors including sleep, stress, medications and health conditions.

Which cognitive abilities have been linked with ultra-processed food intake?

Recent studies have reported associations involving executive function, processing speed, verbal fluency and global cognitive performance. Findings for memory specifically have been less consistent.

Should I completely eliminate ultra-processed foods?

The current cognitive research does not provide evidence that complete elimination is necessary. A more practical approach is to emphasize nutrient-dense, minimally processed foods most of the time while considering your overall dietary pattern rather than treating individual packaged foods as inherently harmful.

BEACON40 Personal is a consumer wellness device. Not intended to diagnose, treat, cure, or prevent any disease. This article is for general educational purposes only and is not a substitute for individualized medical or nutritional advice.