Association Between Consumption of Ultra-processed Foods And Cognitive Decline
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By Fiona Riddle
It is estimated that more than 60 percent of the average American’s caloric intake comes from ultra-processed food. It is important to distinguish ultra-processed from processed foods. Except for the intake of fruits and salads, the great majority of our foods have been processed by cooking, fermentation, canning or freezing. Humans have been practicing some of these processing techniques for thousands of years. However, ultra-processed foods have become increasingly popular during the last 75 years, are manufactured on a large, industrial scale, contain numerous additives and are essentially devoid of any whole foods and adequate nutrition; think potato chips, soft drinks, power bars and sugary breakfast cereals. While rapidly growing rates of obesity are a visible representation of the negative health consequences, and the impacts on cardiovascular health have begun to surface, little discussion has been had about the consequences for brain health and cognitive function.
“It is estimated that around 80 percent of processed foods contain some sort of byproduct from corn, soy and wheat.”
These ultra-processed foods typically contain large amounts of additives, often lab-made artificial ingredients such as flavorings and colors, which not only improve the shelf life and appearance of these foods, but also make them more palatable and even addicting. It is estimated that around 80 percent of processed foods contain some sort of byproduct from corn, soy, and wheat. These commodity grains are cheap to produce and can be turned into a wide variety of ingredients such as refined flours and high fructose corn syrup. The addition of these fillers allow companies to reduce the volume of whole foods found in these products, consequently lowering the nutritional value while at the same time often increasing the total amount of calories.
America’s population is increasingly overfed and yet vastly undernourished. A recent study found that the consumption of whole foods decreased from 32.7 percent to 27.4 percent of calories from 2001 to 2018 and that ultra-processed food consumption increased by 4.5 percent. As more research continues to be conducted, evidence continuously links ultra-processed food to poor diet quality and higher instances of chronic disease and obesity.
A 2019 comparative study found a positive correlation between the sales of ultra-processed food and drink and “population-level body mass index (BMI) trajectories.” While we cannot assume a causal relationship from this association, it does shed light on a likely factor of the increasing rates of obesity and related metabolic diseases given the increasing rates of ultra-processed food consumption.
“…increased consumption of ultra-processed foods was found to be associated with a higher risk of developing cardiovascular, coronary heart, and cerebrovascular diseases.”
In yet another study, increased consumption of ultra-processed foods was found to be associated with a higher risk of developing cardiovascular and cerebrovascular diseases. And while this study suggests only correlational findings as well, it highlights the importance of the need for further investigation.
“higher consumption of ultra-processed foods was associated with a higher rate of global and executive function decline”
Most recently, there is evidence suggesting a similar association between increased consumption of ultra-processed foods and accelerated cognitive decline. A 2022 investigation published in The Journal of the American Medical Association found that “higher consumption of ultra-processed foods was associated with a higher rate of global and executive function decline” after 8 years among the 10,775 participants. In short, a higher percentage of daily energy consumption from ultra-processed foods was associated with increased cognitive decline. Since participants had a mean age of 51.6, the finding suggests that a reduction in caloric intake from ultra-processed foods would help to reduce cognitive decline specifically in middle aged populations.
“Negative health consequences may be related to the nutritional composition, additives or even contaminants that make their way into food products.”
In light of these findings, it is imperative that further research is conducted to investigate the exact reasons behind the negative health outcomes of consuming ultra-processed foods as there are many different possible factors. Negative health consequences may be related to the nutritional composition, high caloric density, additives or even contaminants that make their way into food products and then impact the body’s systems. For example, excess sugar consumption is known to increase rates of systemic immune activation throughout the body leading to metabolic endotoxemia.
While the chemicals and substances added to ultra-processed foods are one plausible explanation, another reason for the association of such foods with negative health outcomes is the lack of health promoting, anti-inflammatory components, such as fiber, polyphenols, and omega-3 fatty acids.
“…choose foods that have minimal ingredients and ingredients that you would find in your own kitchen.”
In order to minimize risk of chronic diseases and premature cognitive decline, ultra-processed food intake should be limited, and a priority should be made to focus on more real, whole foods. A good rule of thumb when grocery shopping is to choose foods that have minimal ingredients, ingredients without complicated chemical names, and ingredients that you would find in your own kitchen. For example, additives such as TBHQ, high fructose corn syrup and artificial flavorings are not a staple in the average American household. An emphasis on a wide variety of high-quality protein and produce have been shown to improve health outcomes in multiple populations.
Fiona Riddle is a Certified Health Coach with a degree in Psychology from UCLA. She is passionate about a holistic approach to health when working with her private coaching clients. She is an avid cook, constantly creating and sharing new recipes on her Instagram (@feelgoodwithfi) to showcase simple clean home cooking.
✓ This article was reviewed and approved by Emeran Mayer, MD