A large-scale study found a significant link between ultra-processed foods and increased dementia risk. Researchers from Tianjin Medical University tracked the diet and health of 72,803 adults in the United Kingdom, all aged 55 and older, for a decade as part of the research.
The numbers behind the risk
For every 10 percent increase in ultra-processed food consumption, the risk of Alzheimer’s disease rose 14 percent, and the risk of dementia overall increased 25 percent. Comparing the extremes, nearly 43 percent more people in the highest ultra-processed food intake group developed dementia than those in the lowest intake group.
There was also good news in the data: replacing just 50 grams of ultra-processed food per day with a healthier, less-processed option was associated with a 3 percent lower risk of dementia — a modest but realistic swap for most people.
What counts as ultra-processed?
Ultra-processed foods typically contain additives, preservatives, and high amounts of added sugar, fat, and salt. They’ve become dietary staples in many households due to convenience and long shelf life, but this and other recent studies suggest that heavy reliance on these products may come at a cognitive cost. A related 2026 study found that for every 10 percent increase in ultra-processed food intake, researchers observed a measurable drop in visual attention and processing speed on standardized cognitive tests.
Foods linked to lower dementia risk
In contrast, other research has identified dietary patterns associated with a lower dementia risk. One study found that people who consumed six servings per day of flavonoid-rich foods — naturally occurring compounds in fruits, vegetables, tea, and dark chocolate — experienced a 28 percent reduction in dementia risk. Other dietary research has linked regular egg consumption to lower Alzheimer’s risk in older adults.
What this means for your diet
Healthcare providers continue to promote dietary guidelines favoring fruits, vegetables, and other flavonoid-rich, minimally processed foods. If a full dietary overhaul feels unrealistic, the research suggests even small, consistent swaps — like the 50-gram substitution noted above — can meaningfully move the needle on long-term brain health. Read more about the connection between diet and cognitive decline from the Alzheimer’s Association.
