Studies have shown that processed food is addictive, increasing the activation of receptors where emotional responses are regulated and feel-good hormones, such as dopamine, reside. It’s been discovered that processed food has the exact same impact on the reward system in the brain as any addictive drug, such as cocaine. Because they cause the same biological responses, those who are susceptible can have the same issues as anyone who suffers with addiction. Studies released late 2022 shared evidence that even consuming 20% of your calories from ultra-processed foods, also puts you at a higher risk of developing dementia.
Ultra-processed foods are items that are generally factory-made and come laden with additives and preservatives like sweeteners and thickeners. They may also contain additives like artificial colors and hydrogenated fats (read here about the difference between dietary fats). Generally, these things are packaged in plastic or cans. You’re likely to see “high fructose corn syrup” on the ingredient list of an ultra-processed food item, or perhaps some interesterified oils (replacements for trans fat) which are now widely banned. A few examples include soft drinks, fast food, packaged cookies, pre-packaged snacks, and more.
One study, published December 2022 in Jama Neurology, explored the connection between ultra-processed foods and cognitive decline. They discovered that the human brain was impacted when people consumed 20% or more of their calories from ultra-processed foods. In a 2,000 a day diet, 20% would equal about 400 calories a day. A 6″ Subway turkey breast sandwich with a small bag of chips and water is 400 calories. A small order of fries and regular cheeseburger from McDonald’s contains a total of 530 calories.
The part of the brain involved in executive functioning-the ability to process information and make decisions- is especially hard hit, according to the study. “People who consumed more than 20% of daily calories from processed foods had a 28% faster decline in global cognition and a 25% faster decline in executive functioning compared to people who ate less than 20%,” said study coauthor Natalia Gonçalves, a researcher in the department of pathology at the University of São Paulo Medical School.
Another study, published July 2022 in the journal American Academy of Neurology, found that after adjusting for age, gender, family history of dementia and heart disease and other factors that could affect risk of dementia, for every 10% increase in daily intake of ultra-processed foods, people had a 25% higher risk of dementia.
These studies are significant, as researchers work to better understand the risk factors behind dementia and how people can combat the risk throughout life- not just in older age.
These studies focused on ultra-processed foods. But when pinpointing how to reduce your overall intake of processed foods, consider that it’s not just fast food, candy, chips, and the usual suspects. There is a spectrum of what is considered processed:
- Minimally processed foods — such as bagged spinach, cut vegetables and roasted nuts — often are simply pre-prepped for convenience.
- Foods processed at their peak to lock in nutritional quality and freshness include canned tomatoes, frozen fruit and vegetables, and canned tuna.
- Foods with ingredients added for flavor and texture (sweeteners, spices, oils, colors and preservatives) include jarred pasta sauce, salad dressing, yogurt and cake mixes.
- Ready-to-eat foods — such as crackers, granola and deli meat — are more heavily processed.
- The most heavily processed foods (often referred to as ultra-processed) often are pre-made meals including frozen pizza and microwaveable dinners, chips, candy, packaged soups, etc. that go through multiple processes.
While it’s no secret that processed food doesn’t do us any favors, Americans as a whole consume nearly 60% of their calories from processed foods. The newest studies on the impact to cognitive function only add to the concern for our health. Over the years, research has found many detriments to regularly consuming processed foods.
For example, one study provided strong evidence that these foods not only tend to make people eat more, but they may also result in dramatic and relatively rapid weight gain and other negative health effects. Another study, published in the journal Cell Metabolism, found that people ate significantly more calories and gained more weight when they were fed a diet that was high in ultra-processed foods like breakfast cereals, muffins, white bread, sugary yogurts, low-fat potato chips, canned foods, processed meats, fruit juices and diet beverages. These foods caused a rise in hunger hormones compared to a diet that contained mostly minimally processed foods like fresh fruits and vegetables, eggs, grilled chicken, fish and beef, and whole grains, nuts and seeds. You can find examples of how to decrease your consumption of processed foods from breakfast, lunch, and dinner foods, here.
Beyond the link to overeating, a diet heavy in processed food is also tied to all kinds of other health problems, including cardiovascular disease, cancer, and the risk of all-cause mortality.
With this new information in mind, limit your exposure to foods that have received higher levels of processing. While processed foods are convenient, in the long run your longevity and quality of life will benefit from healthier choices. On Wednesday, we’ll share a variety of foods that are minimally processed and provide a variety of health benefits.