A recently published review examining links between ultra-processed food consumption and cognitive health found that eating roughly two portions of processed deli meat each day corresponded with a notably elevated dementia risk. Drawing on dozens of human and animal studies — among them a U.K. cohort of close to 500,000 participants — a review published in the August 2026 issue of Annual Review of Nutrition found that every additional 25-gram daily increment of processed meat was associated with a 44% higher rate of all-cause dementia and a 52% higher rate of Alzheimer's disease.
A 25-gram portion of deli meat works out to somewhere between one and two slices, with the final count depending on how thickly each piece has been cut. Conducted by a cross-border panel of 27 researchers, the analysis cast a wider net — probing whether long-term consumption of heavily processed foods plays a role in the gradual decline of brain health.
Ultraprocessed foods — a category that takes in sweetened beverages, packaged snack products, and other items subjected to extensive industrial processing, often formulated with additives such as emulsifiers, preservatives, and synthetic colorants — carry an approval pathway that does not always require a thorough accounting of their effects on the body, including the brain, according to Owen Carmichael, the study's lead author. Carmichael, a researcher based at the Pennington Biomedical Research Center in Baton Rouge, Louisiana, shared those remarks with a broadcast news outlet.
Carmichael drew a distinction between the scrutiny applied to ultra-processed foods and the far more demanding approval pathway that pharmaceutical products must navigate before reaching the public — noting that certain UPFs are manufactured to a level of precision that places them closer in character to drugs than to conventional food, yet the oversight framework governing them operates on an "act first, gather evidence later" basis rather than the reverse. Separately, he outlined two competing scientific hypotheses that researchers are currently testing to understand how regular UPF intake may relate to outcomes in neurological health.
One pathway researchers point to involves UPFs placing strain on cardiovascular function, which in turn may affect the brain — a connection Carmichael summarised by noting that heart health and cognitive health tend to travel together. He noted that, broadly speaking, UPFs tend to cause the most harm below the neck, with organs and tissues such as the heart, blood vessels, muscles, fat deposits, and liver among those affected.
A second line of thinking holds that particular additives in food may interfere with the brain's chemical balance. Carmichael noted that additional investigation into both theories remains warranted.
The review notes that animal-based studies continue to account for a substantial portion of the existing evidence base, while extended randomised clinical trials have yet to be conducted. Those behind the research were careful to note that its observational design means the data on processed meats — a category covering deli turkey, ham, salami, bacon, hot dogs, and sausages — cannot establish a direct causal link to dementia.
Carmichael has long advocated keeping cardiovascular health in mind as a factor in long-term brain health. Guidance on dietary choices for heart health has long pointed toward leafy produce, other vegetables, and oily fish — advice that nutritional thinking across several dietary frameworks continues to echo.
According to the review, drawing on available research, trimming ultra-processed food intake by just one-tenth of daily calories — and filling that gap with whole, unprocessed options — was linked to a 19% reduction in dementia risk. Research in the field indicates that roughly 55 percent of the calories consumed daily by Americans come from ultra-processed food products.
Their low cost, widespread availability, and prominent marketing presence make ultra-processed foods a routine dietary fixture for a broad swath of the population, according to William Scott Burgin, a vascular neurologist at the University of South Florida who also serves as chief medical officer at NeuroEM Therapeutics. Burgin, who had no part in the new study, urged against treating all ultra-processed foods as a single category, pointing out that items such as fortified whole grain cereals, dairy products like yogurt, and packaged breads and grain goods technically fall under that label yet are likely neutral or potentially beneficial to health.
He also drew attention to the fact that the bulk of available evidence rests on observational data rather than controlled dietary trials, before adding that while reducing ultra-processed food intake is worth pursuing, eating a cookie on occasion poses no meaningful concern. Alongside that guidance, a diet drawing heavily on omega-3 fatty acids, antioxidants, and polyphenols was put forward as beneficial, with certain supplements — B vitamins among them — noted as having some research backing.
Requests for comment were directed to two industry bodies — the North American Meat Institute, operating out of Virginia, and the American Association of Meat Processors, whose offices sit in Pennsylvania — by a television news outlet.
