According to a recent study, increasing your daily intake of ultraprocessed foods by just 10%—which is about the amount in a small bag of potato chips—might significantly heighten the risk of developing dementia, even if your overall diet is healthy and plant-based.
Ultraprocessed foods, often labeled as UPFs, account for around 53% of all calories consumed by adults in the U.S. Interestingly, for children, this figure jumps to nearly 62%, as noted by the Centers for Disease Control and Prevention (CDC).
Lead researcher Barbara Cardoso, a senior lecturer in nutrition at Monash University in Melbourne, stated, “Our study showed that UPF consumption was associated with worse attention and increased dementia risk in middle-aged and older adults.”
While the study established a connection, it didn’t specify direct causality. Cardoso mentioned that this link was consistent even among those who followed a Mediterranean diet, hinting that the issue relates more to how these foods are processed than to their nutritional content alone.
Dr. W. Taylor Kimberly, a neurology professor at Harvard Medical School and not part of the research, described the findings as a crucial addition to the growing evidence about the negative impact of ultraprocessed foods on cognitive health.
Kimberly had previously co-authored a study that reported a 16% rise in the risk of cognitive impairment with a 10% increase in ultraprocessed food consumption, even among largely plant-based eaters.
A silver lining exists, however. Kimberly pointed out that individuals who commit to reducing their UPF intake over the long term might see benefits. His earlier research showed that substituting UPFs with whole foods could lead to a 12% lower risk of cognitive decline over five to six years.
For adults in their 50s and 60s, another study revealed that eliminating unhealthy foods from their diets over a decade reduced the risk of Alzheimer’s and dementia by 11% compared to those who made no changes.
The widely praised Mediterranean diet, rich in whole grains, vegetables, and healthy fats, is associated with lower risks of various diseases including cancer, diabetes, and cardiovascular issues. This is especially relevant for individuals carrying two copies of the APOE4 gene, a significant Alzheimer’s risk factor.
Other renowned plant-rich diets, like the DASH and MIND diets, also promote whole foods while minimizing sugar and ultraprocessed items. They have been linked to improvements in overall health, including blood pressure and heart health, which can positively affect brain function.
Ultraprocessed foods, on the other hand, are largely devoid of whole food components. They involve breaking down whole grains and other foods into their molecular components, then reconstituting them with artificial additives. Experts caution that these “predigested” foods, often high in sugar, salt, and fats, may lack essential nutrients for both body and brain health.
A 2022 study involving 10,000 participants found that those with the highest ultraprocessed food intake experienced a 25% faster decline in executive functions and a 28% quicker rate of overall cognitive impairment compared to those who consumed the lowest amounts.
Concerns about the health hazards of ultraprocessed foods are increasing. A February 2024 review encompassing 45 studies with around 10 million participants highlighted that just a 10% increase in consumption could elevate the risk of various health issues.
This increment was seen as a baseline, implying that an even greater intake of ultraprocessed foods might pose additional risks.
The review indicated a strong correlation between high ultraprocessed food consumption and a nearly 50% increased risk of death from cardiovascular diseases, as well as mental health disorders. Other findings suggested that these foods could raise the risk of obesity by 55%, sleep disturbances by 41%, type 2 diabetes by 40%, and depression by 20%.
Attention Span and Dementia Risk
The latest study, published in the journal Alzheimer’s & Dementia, engaged over 2,100 Australians aged 40 to 70. Participants documented their diets over the past year, revealing that about 42% of their food intake consisted of ultraprocessed options.
Alongside dietary assessments, participants also took cognitive tests to measure attention and information processing speed. Importantly, none had dementia at the study’s start.
Cardoso observed a clear trend: “For every 10% increase in ultraprocessed food consumption, we noted a distinct and measurable decline in attention.” This drop was reflected in standardized tests that assess visual attention and processing speed.
Attention span plays a crucial role in various brain functions, including learning and problem-solving. Although a direct link between UPFs and memory wasn’t established, the researchers did predict cognitive decline using a tool designed to assess dementia risk over the next two decades.
The research indicated that a 10% increase in UPF consumption corresponded to an increase of 0.24 points in dementia risk on a scale from 0 to 7. So, consuming ultraprocessed pancakes for breakfast, chips for lunch, cookies for snacks, and pizza for dinner can add up quickly.
Cardoso suggested that eliminating ultraprocessed foods could potentially lower risks, particularly if done before neurological issues arise.
“Midlife is an opportune moment to tackle modifiable risk factors before changes compatible with dementia occur,” she explained.
She added that ultraprocessed foods are linked to negative changes in the body’s systems, such as the endocrine system and gut microbiota, which may lead to adverse neurological outcomes. Furthermore, they are associated with cardiovascular risk markers for dementia, including diabetes, hypertension, obesity, and elevated LDL cholesterol, potentially affecting cognitive health indirectly.
