A new review of ultra-processed foods (UPFs) and brain health has found that consuming just two slices of deli meat per day is associated with a substantially higher risk of dementia. The review, published in the August 2026 issue of Annual Review of Nutrition, analyzed dozens of human and animal studies, including one involving nearly 500,000 people in the UK.
The study found that each additional 25 grams of processed meat eaten daily corresponded with a 44% higher risk of all-cause dementia and a 52% higher risk of Alzheimer's. This amount of processed meat is equivalent to roughly one to two slices of deli meat, depending on the thickness of the slice. The review's authors noted that this association is observational and does not prove that processed meat directly causes dementia.
The review, conducted by an international team of 27 researchers, looked at the broader question of whether diets high in UPFs may contribute to brain aging over time. UPFs include sugary drinks, packaged snacks, and other heavily industrially processed foods that often contain ingredients such as emulsifiers, preservatives, and artificial colors.
Lead author Owen Carmichael, Ph.D., of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, noted that many UPFs are highly engineered and may have unintended health effects. He emphasized that researchers are still investigating the mechanisms by which UPFs may contribute to brain health, with two leading theories being that UPFs can damage heart and blood vessel health, indirectly affecting the brain, and that certain food additives may disrupt brain chemistry.
The authors of the review emphasized that more research is needed to fully understand the relationship between UPFs and brain health. They noted that much of the current research comes from animal studies, and long-term randomized clinical trials are still lacking.
NTC Report coverage is based on reporting from the original publisher.
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