“Regular consumption of ultra-processed foods significantly increases the risk of developing dementia.”

High (vs. low) intake of UPF was associated with increased risk of dementia (pooled relative risk 1.44 (95% confidence interval 1.09–1.90) (p = 0.02)) (I^2 = 97.0%), although moderate (vs. low) intake of UPF was not (1.12 (0.96–1.31) (0.13)) (85.0%). ... We present the first systematic review and meta-analysis to assess the association between ultra-processed food consumption and dementia, convincingly demonstrating that high UPF intake is associated with dementia.

High (vs. low) intake of UPF was associated with increased risk of developing all-cause dementia (pooled RR 1.44 (1.09–1.90) (p = 0.02)), with high heterogeneity (97.0% (p < 0.01))... High UPF consumption is associated with dementia. Public health measures to reduce overconsumption of UPFs are imperative to reduce the burden of dementia.

Consumption of an additional average daily serving of ultraprocessed animal products and beverages were associated with 17% (95% Confidence interval [CI]: 1.032, 1.326) and 6.3% (95% CI: 1.010, 1.118) heightened risk of developing cognitive impairment throughout the study period, respectively. Total UPF consumption and consumption of other UPF categories (other, sweets, spreads, savory snacks, ready-to-eat meals, grains, and dairy-based) were not associated with risk of developing cognitive impairment.

The findings show that total UPF intake was not associated with either the level of cognitive function or with cognitive decline with aging for any of the assessed domains, including global cognition, information processing speed, episodic memory, or executive function.

High UPF consumption is associated with dementia. Public health measures to reduce overconsumption of UPFs are imperative to reduce the burden of dementia. High (vs. low) intake of UPF was associated with increased risk of dementia (pooled relative risk 1.44 (95% confidence interval 1.09-1.90) (p = 0.02)).

As we move into 2025 and 2026, the scientific consensus has evolved from establishing a broad association to dissecting the specific “culprits” within the UPF category and identifying the biological mechanisms at play. These latest findings suggest that not all UPFs are created equal; specifically, ultra-processed meats (like deli meats and hot dogs) and sugar-sweetened beverages show the most robust and consistent links to cognitive impairment and poor memory, whereas some other ultra-processed categories, such as certain whole-grain breads or dairy-based UPFs, may not carry the same degree of risk. A 2026 report utilizing data from the Health and Retirement Study (HRS) at the NIH found that high UPF consumption is particularly detrimental to executive function—the mental skills used for self-regulation and focus—even before a formal dementia diagnosis is made.

Our results indicated that high UPF intake was associated with increased risks of incident dementia (hazard ratio [95% confidence interval] = 1.37 [1.08, 1.74]), Parkinson's disease (1.76 [1.22, 2.53]), and multiple sclerosis (2.38 [1.02, 5.55]), with stronger associations observed in participants with lower polygenic risk score. Moreover, high UPF intake corresponded to extensive gray matter compromise, including reduced subcortical volumes with right-hemispheric predominance, and widespread cortical deterioration in volume, thickness, and surface area.

Between 1980 and 2024, 139 human observational or intervention studies were published that examined the role of these individual dietary patterns in brain aging. When systematically reviewed using the USDA Nutrition Evidence Systematic Review method and an a priori established protocol, a common theme emerged: diets characterized by higher consumption of vegetables, fruits, legumes, nuts, fish, seafood, and unsaturated vegetable oils, alongside lower intake of red and processed meats and sugar-sweetened beverages, are consistently associated with a reduced risk of cognitive decline and dementia.

Research has suggested that UPF consumption is associated with higher risk of all-cause dementia, and Alzheimer's disease (12, 13).

The new DGAs explicitly say that “highly processed” foods such as “packaged, prepared, ready-to-eat (RTE), or other foods that are salty and sweet… that have added sugars and sodium” should be avoided. For the first time, we're calling out the dangers of highly processed foods.

We present the first systematic review and meta-analysis to assess the association between ultra-processed food consumption and dementia, convincingly demonstrating that high UPF intake is associated with dementia and suggesting that ultra-processed diets could contribute to cognitive impairment. High (vs. low) intake of UPF was associated with increased risk of dementia (pooled relative risk 1.44 (95% confidence interval 1.09–1.90) (p = 0.02)).

A study has found that the emotional memory region of the brain, the amygdala, is sensitive to processed foods. The study links the finding mainly to the diet's lack of fiber, which leads to a decline in gut-derived butyrate metabolites and may cause inflammation in the brain. “We found that all of the refined diets — whether they were high fat, high sugar, low fat, or low sugar, it didn't matter — impaired memory that's governed by the amygdala,” says co-lead author Ruth Barrientos.

Researchers looked at the dietary habits of more than 72,000 people ages 55 and older without dementia and followed them over an average of 10 years. Even after adjusting for other established risk factors, the researchers calculated a 25% higher risk for dementia in people eating the largest amounts of these foods compared with those who ate little of them.

A massive brain imaging study of nearly 30,000 people has uncovered striking connections between eating ultra-processed foods and measurable changes in brain structure. These changes may be tied to overeating and addictive eating patterns, though scientists caution that more research is needed to confirm cause and effect.

A recent study published in JAMA Neurology reported that healthy dietary patterns are linked to a lower risk of subjective cognitive decline (SCD), an early sign of cognitive problems. The results also showed that higher consumption of vegetables and fish, with lower intake of red and processed meats, was associated with healthier cognitive outcomes. In contrast, fried potatoes, sugary drinks, sweets, and processed meats were linked to poorer cognition.

While the results of this study do not prove cause and effect, the robust study methodology and large sample size are sufficient to conclude that ultraprocessed foods should be limited to avoid potential negative impacts to an individual’s cognitive function.

Researchers found that these ultra-processed foods can be linked to poor memory and cognitive issues in a new study published in the American Journal of Clinical Nutrition. By the end of the study period, they found a 17 percent increase in cognitive issues among people who consumed at least one serving of ultra-processed meat a day. And for each serving of soda consumed, there was a 6 percent increase in cognitive impairment.

Of the four included studies, three showed a significant association between ultra-processed foods consumption and the risk of developing Alzheimer's disease. The addition of 10% UPF in the diet was associated with a significant 13% increase in the risk of incidence of AD. Of the studies included in our review, Li et al. (20) in a cohort involving 118,528 adults and elderly individuals, found that higher consumption of UPF was associated with a higher risk of incidence of AD.

People whose diets had the highest levels of ultraprocessed foods (20% of calories or more) showed a 28% faster rate of overall cognitive decline, according to the researchers from the University of São Paulo, other universities in Brazil, and the Harvard T.H. Chan School of Public Health in Boston. Those eating the highest levels of ultraprocessed foods (UPFs) also showed a 25% faster rate of executive function decline.

Results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), which included more than 10,000 people aged 35 and older, showed that higher intake of UPF was significantly associated with a faster rate of decline in executive and global cognitive function.

Two recent large-scale studies suggest that eating ultra-processed foods may exacerbate age-related cognitive decline and increase the risk of developing dementia. In contrast, another recent study reported that ultra-processed food consumption was not associated with worse cognition in people over 60. This was a relatively modest difference in the rate of cognitive decline between experimental groups.

This week's study is a meta-analysis that examined the relationship between ultra-processed food intake and neurodegenerative disorders, including multiple sclerosis (MS), Parkinson's disease (PD), Alzheimer's disease (AD), cognitive impairment, and dementia. The results revealed that increased ultraprocessed food consumption was associated with a: 15% increased risk of developing multiple sclerosis. 56% increased risk of developing Parkinson's disease. 17% increased risk of cognitive impairment (specifically not dementia, including Alzheimer's -type dementia).

A study following over 130,000 Americans linked consuming processed red meats such as bacon and hot dogs to a 14% increased risk of dementia. Additional research suggests diets high in ultraprocessed foods could harm brain health by affecting blood vessels, displacing healthy nutrients and promoting inflammation.

The World Health Organization recognizes diets high in ultra-processed foods as a risk factor for multiple non-communicable diseases, including those affecting brain health, though specific longitudinal data on dementia causation remains observational and requires further RCTs for causality.