Eating just two slices of deli meat a day was associated with a substantially higher risk of dementia, according to a new review of ultra-processed foods (UPFs) and brain health.
The findings, published in the August 2026 issue of Annual Review of Nutrition, looked at dozens of human and animal studies, including one involving nearly 500,000 people in the U.K. 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.
Twenty-five grams of processed meat equals roughly one to two slices of deli meat, depending on how thick the meat is sliced.
The review, done by an international team of 27 researchers, looked more broadly at 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.
“The main takeaway for consumers is that it is very easy to get food items into the food supply without really understanding what kinds of effects they have on health, including the health of the brain,” lead author Owen Carmichael, Ph.D., of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, told Fox News Digital.
Some UPFs are so highly engineered that they “look like pharmaceuticals,” Carmichael said.
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“Yet they don’t face anywhere near the scrutiny pharmaceuticals face when trying to get on the market,” he added. “When it comes to food safety, we sort of shoot first and ask questions later.”
Carmichael said researchers are investigating two leading theories on why UPFs are linked to brain health.
One is that UPFs can damage heart and blood vessel health, indirectly affecting the brain. “Healthy heart, healthy mind,” he said.
In general, he said UPFs are “especially bad for your health from the neck down, damaging the heart, blood vessels, muscle, fat [and] liver.”
The other theory is that certain food additives may disrupt brain chemistry.
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Both theories need further research, Carmichael said.
Much of the current research still comes from animal studies, according to the review, and long-term randomized clinical trials are still lacking.
The authors emphasized that the findings are observational and cannot prove that processed meat, which includes deli turkey, ham, salami, bacon, hot dogs and sausages, directly causes dementia.
But for people looking to improve long-term brain health, Carmichael’s “healthy heart, healthy mind” rule still applies.
Many dietary recommendations overlap with long-standing heart-health advice, such as eating more fruits, vegetables and fish.
The review cited research suggesting that replacing just 10% of calories from UPFs with unprocessed foods could lower dementia risk by 19%. Ultra-processed foods make up about 55% of Americans’ daily calories, experts note.
UPFs tend to be inexpensive, convenient and heavily marketed — making them easy for many people to consume regularly, Dr. William Scott Burgin, a vascular neurologist at the University of South Florida and chief medical officer for NeuroEM Therapeutics, told Fox News Digital.
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“UPFs are probably the worst for brain health,” said Burgin, who was not involved with the new research.
But he cautioned against lumping all UPFs together.
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“There are foods that get technically classified as ultra-processed, but are more likely neutral or may even be good for you, such as fortified whole grain cereals, dairy-based foods like yogurt, and packaged breads and grain products.”
Burgin also noted that most of the evidence comes from observational studies rather than research assigning people to specific diets.
“All that being said, while I encourage people to reduce their consumption of UPFs, a cookie every now and then is not a problem,” he said.
He also encouraged a diet rich in omega-3s, antioxidants and polyphenols, while noting that some evidence also supports supplements such as B vitamins.
Fox News Digital reached out to The Meat Institute, headquartered in Virginia, and The American Association of Meat Processors, based in Pennsylvania, for comment.
