Eating more ultra-processed foods tied to cognitive decline, stroke
People who eat more ultra-processed foods like soft drinks, chips and cookies may have a higher risk of having memory and thinking problems and having a stroke than those who eat fewer processed foods. That’s according to a new study published in the May 22, 2024, in the journal Neurology®, the medical journal of the American Academy of Neurology.
The study does not prove that eating ultra-processed foods causes memory and thinking problems and stroke. It only shows an association.
What are ultra-processed foods (UPFs)?
UPFs are industrial formulations made from components extracted from whole foods that chemically modified. They contain numerous additives to enhance taste, texture, appearance and shelf-life. They contain little, if any, whole food.
Ultra-processed foods are high in added sugar, fat and salt, and low in protein and fibre
UPFs comprise of a broad range of ready-to-eat products including soft drinks, packaged snacks, mass-produced breads, muffins, pastries and cookies, protein bars, ice cream, processed meats, frozen foods and meals (e.g., French fries, pizza, chicken nuggets), margarine and many more.
Unprocessed or minimally processed foods include meats such as simple cuts of beef, pork and chicken, unsweetened yogurt, milk, vegetables and fruits.
About the study
For the study, researchers from Massachusetts General Hospital in Boston looked at 30,239 people aged 45 or older who self-identified as Black or white. They were followed an average of 11 years.
Participants filled out questionnaires about what they ate and drank.
Researchers determined how much ultra-processed food people ate by calculating the grams per day and comparing it to the grams per day of other foods to create a percentage of their daily diet. That percentage was calculated into four groups, ranging from the least processed foods to the most processed foods.
Of the total participants, researchers looked at 14,175 participants for cognitive decline and 20,243 participants for stroke. Both groups had no history of cognitive impairment or stroke.
Related: Ultra-processed foods tied to increased cancer risk
The findings
By the end of the study, 768 people were diagnosed with cognitive impairment and 1,108 people had a stroke.
For those in the cognitive group, people who developed memory and thinking problems consumed 25.8% of their diet in ultra-processed foods, compared to 24.6% for those who did not develop cognitive problems.
After adjusting for age, sex, high blood pressure and other factors that could affect risk of dementia, researchers found that a 10% increase in the amount of ultra-processed foods eaten was associated with a 16% higher risk of cognitive impairment.
They also found that eating more unprocessed or minimally processed foods was linked with a 12% lower risk of cognitive impairment.
For those in the stroke group, people who had a stroke during the study consumed 25.4% of their diet in ultra-processed foods, compared to 25.1% for those who did not have a stroke.
After adjustments, researchers found greater intake of ultra-processed foods was linked to an 8% increase in risk of stroke, while greater intake of unprocessed or minimally processed foods was linked to a 9% decreased risk of stroke.
The effect of ultra-processed food consumption on stroke risk was greater among Black participants, with a 15% relative increase in risk of stroke.
"Our findings show that the degree of food processing plays an important role in overall brain health," said the lead researcher. "More research is needed to confirm these results and to better understand which food or processing components contribute most to these effects."
A limitation of the study was that only participants who self-identified as Black or white were included in the study, so results may not be generalizable to people from other populations.
Source: Neurology, May 22, 2024
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