Ultra-Processed Foods and Brain Scans: What the New Study Found, and What It Did Not

On 18 October 2026, Fox News ran a story with the headline "Popular foods Americans eat every day linked to silent brain damage, alarming study finds." It is based on a study in JAMA Network Open. The study is real. The headline goes further than the study does.

What the study did

Researchers in Canada looked at 8,783 adults aged 35 to 69. None had heart disease. People answered a food questionnaire. Each person also had a body scan and a brain MRI.

This is a cross-sectional study. That means it took one snapshot in time. It compared people who ate more ultra-processed food with people who ate less.

What it found

People in the highest fourth of ultra-processed food intake, compared with the lowest fourth:

• Had about 1.7 percentage points more body fat.
• Had a larger volume of visceral fat, the fat deep in the belly.
• Had 40% higher odds of small changes on brain MRI that doctors call vascular brain injury (adjusted odds ratio 1.40, 95% confidence interval 1.10 to 1.77).

The researchers did not find a significant link between ultra-processed food intake and scores on two memory and thinking tests. They say the brain MRI link was sensitive to how ultra-processed food was defined. They say longer studies that follow people over time are needed to show what comes first.

Where the headline goes further

• "Brain damage" describes small MRI changes. These people had no heart disease and no reported memory problems. The study did not find a memory or thinking difference.
• The study cannot show that ultra-processed food caused the changes. People who eat more of it may differ in other ways too, such as exercise and income.
• A higher chance of a finding is not the same as having it. The study reports odds across a large group. It cannot tell any one person what will happen to them.

Why a cancer site is covering it

The same pattern has come up with cancer. A 2026 review we covered found that higher ultra-processed food intake was linked to a modestly higher risk of digestive cancers, mostly colorectal. It also could not show cause. See what that review found.

NCI says that obesity raises the risk of many cancers. This new study found more body fat in people who ate more ultra-processed food. That is one possible route, but this study did not test it.

How common these foods are

The CDC reports that, from August 2021 to August 2023, people in the United States aged 1 and older got about 55% of their daily calories from ultra-processed foods. For adults it was 53%. For youth aged 1 to 18 it was 61.9%. CDC says those shares were lower than in 2017 to 2018.

So this is not a niche diet. The question is useful, but one study does not settle it.

What you can do now

• The steps that NCI lists for lowering cancer risk still apply: keep a healthy weight, be active, limit alcohol, and do not smoke. NCI's page on diet and cancer risk has details.
• Ask your care team before you make big diet changes, especially during cancer treatment.
• If you have new memory problems, weakness on one side, trouble speaking or a sudden severe headache, call 911 right away. Do not wait to see if it passes.

What this does not mean

• It does not mean any single food causes cancer or brain damage.
• It does not mean a brain MRI is needed because of what you eat.
• It does not prove that cutting back on ultra-processed food will prevent stroke, memory loss or cancer.

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

Cancer Explained is published by the National Cancer Information Foundation. It is not medical advice and does not suggest a test or treatment.

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