Eating large quantities of ultra-processed foods has been linked to several health concerns, including heart health issues, chronic infections, and inflammatory bowel disease. Now, a new study conducted by researchers from Ohio State University has found that highly processed foods may also increase the risk for long-term memory concerns.
However, the team points out that when processed foods are supplemented with DHA -- the omega-3 fatty acid -- it may help to lower the risk of memory decline.
“These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficits -- and in the aging population, rapid memory decline has a greater likelihood of progressing into neurodegenerative diseases such as Alzheimer’s disease,” said researcher Ruth Barrientos. “By being aware of this, maybe we can limit processed foods in our diets and increase consumption of foods that are rich in omega-3 fatty acid DHA to either prevent or slow that progression.”
How diet impacts memory function
For the study, the researchers had three-month and 24-month old mice divided into three different diet groups. One group ate their typical diet, another group followed a highly processed diet, and a third group followed a processed diet with DHA supplements. The mice followed the diets for four weeks, after which the researchers analyzed their brain scans to see how the diets impacted their memory function.
The researchers observed that the older mice exhibited the greatest changes to brain and memory function, regardless of which diet they followed. However, the older mice that followed the highly processed diet showed signs of memory loss and had higher inflammatory properties in the hippocampus and amygdala.
“The amygdala in humans has been implicated in memories associated with emotional -- fear and anxiety-producing -- events,” Barrientos said. “If this region of the brain is dysfunctional, cues that predict danger may be missed and could lead to bad decisions.”
There were some positive findings though. The researchers learned that the older mice had better brain health outcomes when DHA supplements were mixed into their diets. These mice had fewer inflammatory markers in their brain scans and also showed fewer symptoms associated with memory loss.
In terms of how consumers can use these findings to their benefit, the researchers recommend prioritizing healthy foods. While the DHA supplements were beneficial, eating an unlimited amount of processed foods isn’t likely to yield the best long-term health outcomes.
“These are the types of diets that are advertised as being low in fat, but they’re highly processed,” said Barrientos. “They have no fiber and no refined carbohydrates that are also known as low-quality carbohydrates. Folks who are used to looking at nutritional information need to pay attention to the fiber and quality of carbohydrates. This study really shows those things are important.”