A diet high in processed foods quickly leads to brain inflammation and memory decline. That was the alarming conclusion from a study in lab rats by scientists known for their expertise in evaluating how everyday life events impact brain inflammation.

 
For this study scientists put both young rats and older rats on one of three diets: a normal rat chow diet, a highly processed diet, and a highly processed diet supplemented with DHA, a brain-healthy omega 3 fat. The processed diet was designed to mimic foods commonly eaten by most Americans, including foods high in refined, fiber-less carbs like potato chips and frozen pizza and pasta dishes. 

The results? After just 4 weeks, the older rats eating the processed food diet displayed marked inflammation in their brains. What’s more, the inflammation was accompanied by clear-cut memory deficits. Examining the older rats’ memory centers, the hippocampus, the scientists noted significant pro-inflammatory gene activation. The lead scientists commented that the rapid onset of inflammation and memory decline observed “was alarming.” The younger mice consuming the processed food diet did not appear to develop significant brain inflammation, although both the aged and the younger rats gained significant weight on the processed food diet.

 
On a positive note, the older rats that consumed the processed diet supplemented with the omega-3 fat, DHA, did not experience brain inflammation or memory changes, suggesting that DHA may protect against adverse neuroinflammation.

Processed foods are clearly emerging as a major player in America’s epidemic of diet-related chronic diseases. If anyone asked me what I consider the #1 diet change to improve health – hands down it would be to avoid processed foods.

Brain, Behavior, and Immunity, 2021; 98: 198 DOI: 10.1016/j.bbi.2021.08.214