Ultra-Processed Food and Your Brain: What a Major Study Found About Stroke and Memory

We already know that ultra-processed foods are linked to problems like weight gain and heart disease. Now a large study has added the brain to that list, connecting a diet high in ultra-processed food with a greater risk of stroke and of memory and thinking problems. It is worth understanding what the research actually found, what it does and does not prove, and what it means for the way we eat.

What the study found

Published in the journal Neurology in May 2024, the study drew on data from a long-running project called REGARDS, which followed more than 34,000 adults in the United States aged 45 and over. Researchers looked at thousands of participants over time, tracking their diets alongside their brain health.

The headline findings were striking. A 10 percent increase in the proportion of ultra-processed food in someone's diet was associated with a 16 percent higher risk of cognitive impairment, meaning problems with memory and thinking, and an 8 percent higher risk of stroke. Encouragingly, the reverse was also true: a 10 percent increase in unprocessed or minimally processed foods was linked to a 12 percent lower risk of cognitive impairment and a 9 percent lower risk of stroke.

An important word of caution

Before anyone panics, this kind of study shows an association, not proof of cause and effect. It cannot say for certain that ultra-processed food directly causes stroke or cognitive decline, only that the two tend to go together in the data. People who eat a lot of ultra-processed food may differ in other ways too, and researchers do their best to account for that, but observational studies always come with this limit. The findings are a strong signal worth taking seriously, not a reason to fear a single biscuit.

What counts as ultra-processed food?

Ultra-processed foods are industrial formulations made largely from substances extracted from foods, along with additives, colours, flavourings and preservatives, rather than whole ingredients you would recognise in a kitchen. Typical examples include fizzy drinks, mass-produced snacks and crisps, packaged biscuits and cakes, sweetened breakfast cereals, instant noodles and many ready meals. The defining feature is not just that they are processed, but that they are heavily reformulated and often designed to be very easy to overeat.

Why might these foods affect the brain?

The study did not set out to prove exactly how ultra-processed food might harm the brain, but scientists have several reasonable ideas. Diets high in these foods tend to be high in salt, sugar and unhealthy fats, all of which can affect blood pressure and blood vessels, and healthy blood flow matters enormously for both stroke risk and brain health. Some research also points to inflammation and effects on the gut. And there is a simpler factor at work too: the more room ultra-processed food takes up on your plate, the less room there is for the nutritious whole foods that support the brain. These are plausible explanations rather than settled conclusions, but they fit with what we know about diet and health more broadly.

The hopeful part: whole foods pushed the other way

Perhaps the most useful takeaway is the positive one. In the same study, eating more unprocessed and minimally processed foods was associated with a lower risk. That is genuinely encouraging, because it suggests the goal is not simply to fear certain foods but to make room for better ones. Shifting the balance of your plate towards whole ingredients appears to be a change worth making.

Simple ways to shift the balance

You do not need a perfect diet to move in the right direction. The aim is to gradually crowd out ultra-processed items with simple, minimally processed foods you can build meals around. Wholegrains such as oats are an easy starting point, so a bowl of porridge made from our Organic Jumbo Oats is a far cry from a sugary packet cereal. Nuts and seeds make a brilliant swap for packaged snacks, and a handful of nuts or a spoonful of seeds adds healthy fats and fibre without a long ingredients list. Pulses, wholegrains, fruit, vegetables and simple cupboard staples all belong in the same camp: recognisable foods, minimally messed with.

None of this means never enjoying a treat. It means making whole, minimally processed foods the everyday default and treating heavily processed items as the exception. Small, steady swaps add up, and this research is a timely reminder that what is good for your heart is very likely good for your brain too.

This article is for general information and is not medical advice. If you have concerns about stroke risk, memory or your diet, particularly if you have an existing health condition, it is worth speaking to a doctor or a registered dietitian.