Processed foods—chips, soda, frozen meals, the kinds of foods designed to have a long shelf life and be easy to prepare—pose significant health problems. They are often high in unhealthy dietary components, such as sodium and unsaturated fats. To make matters worse, processed foods make up a big part of many diets in the U.S. A comparison of processed food consumption across socioeconomic groups between 2007 and 2012 showed that processed foods made up nearly 60% of all calorie consumption across groups.
Heavy consumption of these kinds of foods can also cause a range of physical health problems, such as diabetes, obesity, and heart disease. However, according to new research published in Brain, Behavior, and Immunity, regular consumption of processed foods may also lead to memory problems.
Researchers fed a diet similar to eating processed foods to young and aging rats for about four weeks. Results of this study found that aging rats had higher rates of inflammation in brain cells as well as signs of memory loss. Specifically, older rats (but, interestingly, not younger rats) should “impaired hippocampal- and amygdalar-dependent memory function.” Because adult brains already experience higher levels of inflammation, they may be more susceptible to more severe effects from additional inflammation.
"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 a senior study author, Ruth Barrientos.
The study also suggested that consumption of the omega-3 fatty acid DHA by rats both prevented and reduced inflammation in the aging rats. DHA, often found in fish and fish oils, is known to have a range of health benefits, such as helping your body manage inflammation.
However, researchers cautioned that just because DHA helps, it is not a get out of jail free card. You can’t just eat whatever you like so long as you are taking regular supplements of DHA. Because the study was completed in rats, there are still many unanswered questions about effective dose amounts of DHA. Paying more attention to diet overall—including looking more critically at a food’s fiber and carbohydrate quality—is a much better first step.