Ultra-processed foods linked to higher dementia risk and lower attention scores in study

An Australian study has linked consuming ultra-processed foods (UPFs) to a higher risk of developing dementia and lowered attention scores. Each 10% of increased UPF consumption showed these negative impacts, even when the participants followed an otherwise healthy diet. 

The study stresses that UPFs are linked to over 30 adverse health outcomes, including cardiovascular disease, obesity, type 2 diabetes, mental disorders, and mortality.

UPFs constitute over half of total dietary intake in high-income countries such as the US and the UK, and around 42% in Australia. Low- and middle-income countries are also seeing an increase.

Food processing

The study, published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, found that the results were independent of what other diet the participants were following. This indicates that even if individuals were eating mostly healthy, a slight increase in UPF consumption was associated with a higher risk of dementia and decreased attention span.

The findings point to the negative impacts on brain health being driven by the degree of food processing. 

“Food ultra-processing often disrupts the food matrix, reduces whole-food constituents (such as phytochemicals, vitamins, and minerals), and introduces potentially harmful substances such as bisphenols, phthalates, or processing-derived compounds like acrylamide, which may contribute to adverse neurocognitive outcomes,” notes the study.

“UPFs are also associated with increased risk for chronic diseases such as diabetes, hypertension, obesity, and high LDL cholesterol, which are major contributors to dementia risk that collectively account for approximately 12% of all dementia cases globally.”

The findings point to the negative impacts on brain health being driven by the degree of food processing.It details that these cardiometabolic pathways may explain the negative association between UPF consumption and attention, but not memory, given the higher sensitivity of attention and function to environmental and psychological stressors.

The findings also align with the hypothesis that healthy foods are associated with increases in white matter in the brain, while Western diets have proven to decrease the hippocampal volume — the hippocampus being the brain’s key structure for memory and learning.

Another previously studied health impact of UPFs is that they can disrupt the gut microbiota, which causes a shortage of short-chain fatty acids production, inflammation, and gut barrier function.

“By identifying food processing as a distinct contributor to poorer cognitive outcomes, our study supports the need to refine dietary guidelines for optimal cognitive function, accounting not only for nutrient composition but also for the degree of processing,” note the study authors.

Prior studies on food processing

A recent report emphasized the distinctions between different types of UPFs, arguing that certain healthier options, such as plant-based foods, in this category should be exempted from food policies discouraging consumers from eating them. 

Contrary to this, another study suggested that UPFs with mainly plant-based ingredients are not necessarily healthier, as they were still linked to a higher risk of cardiovascular diseases and death.

Prior studies have also linked UPF consumption to increased risk of neurological diseases such as Parkinson’s and Alzheimer’s disease. It has also shown associations with weight gain, hormone disruption, and lower sperm quality in men.