Cognitive decline 12% less likely if you avoid ultra-processed foods, study suggests

Researchers found an association between ultra-processed foods and cognitive decline and strokes.

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Published: May 22, 2024 at 7:00 pm

Ultra-processed foods (UPFs) have a bad reputation: they are the go-to term when talking about unhealthy eating and have been linked to all sorts of health risks over the years. Now, things could be looking worse once again.

Those with a diet high in UPFs – which includes chips, mass-produced breads, crisps, sweetened breakfast cereals, cookies and soft drinks – might have a higher risk of memory and thinking problems, as well as a greater likelihood of suffering strokes.

This is according to a new study published in the medical journal of the American Academy of Neurology. The findings do not prove that UPFs actually cause these symptoms, but they do show an association between the two.

“While a healthy diet is important in maintaining brain health among older adults, the most important dietary choices for your brain remain unclear,” points out W Taylor Kimberly, the study author and neurologist at Massachusetts General Hospital.

“We found that increased consumption of ultra-processed foods was associated with a higher risk of both stroke and cognitive impairment, and the association between ultra-processed foods and stroke was greater among Black participants.’’


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The study involved the participation of 30,239 people, aged 45 or older and all self-identifying as Black or white.

Each participant filled out questionnaires concerning their diet. From the responses, the researchers determined how many UPFs people ate using a calculation of the grams per day then compared that to the grams per day of other foods, which gave a percentage of UPFs in their daily diets.

Researchers then examined a total of 14,175 participants for cognitive decline and 20,243 for stroke. Both groups had no history of such impairments and conditions.

By the end of the study, 768 people were diagnosed with cognitive impairment while 1,108 people had a stroke.

It was found that those in the first group had consumed 25.8 per cent of their diet in UPFs, compared to 24.6 per cent for those with no diagnosis. When adjustments were made for factors like age, sex and high blood pressure, researchers found a 10 per cent increase in the amount of UPFs eaten was associated with a 16 per cent higher chance of cognitive impairment.

Meanwhile, eating more unprocessed or minimally processed foods was linked with a 12 per cent lower risk of cognitive impairment.

In the group that had suffered a stroke, the numbers are similar: they consumed 25.4 per cent of their diet in UPFs, compared to 25.1 per cent for those who did not have a stroke.

And again, the number goes up after adjustments, with researchers finding an 8 per cent increase in the risk of strokes for those with UPF-rich diets. The study also notes that the risk is even higher among Black participants, at 15 per cent.

While the results can serve to highlight the negative effects of eating UPFs, it is worth clarifying that the study only used participants who self-identified as Black or white. The findings do not necessarily apply to the entire population.

“Our findings show that the degree of food processing plays an important role in overall brain health,” says Kimberly. “More research is needed to confirm these results and to better understand which food or processing components contribute most to these effects.”

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