Ultraprocessed foods (UPFs) make up nearly three-quarters of the entire U.S. food supply and about 60% of Americans’ daily caloric intake. A significant body of research has tied consumption of these foods – awash in added sugar, salt, fat, artificial colors, or preservatives – to cancer, diabetes, and heart disease.
Now, a growing number of studies also link them to poor brain health, including an increased risk of dementia, depression, and anxiety, and some experts are calling for public health policies aimed at reducing UPF consumption.
A mainstay of diets in countries around the world, UPFs have come under increasing scrutiny because of their link to major diseases. The ingredients in UPFs add little or no nutritional value. Their primary function is to increase a product’s shelf life and palatability. Some recent evidence suggests these foods may be as addictive as tobacco. In addition, two pooled analysis studies using the Yale Food Addiction Scale showed that 14% of adults and 12% of children in the United States may have a UPF addiction.
The most widely used measure of what is, and what is not, a UPF was developed in 2009 by researchers in Brazil. The NOVA food classification system assigns food and beverages to one of four groups:
- Unprocessed and minimally processed foods, such as fruits, vegetables, milk, and meat.
- Processed culinary ingredients, including white sugar, butter, and oils derived from seeds, nuts, and fruits.
- Processed foods, such as tomato paste, bacon, canned tuna, and wine.
- Ultraprocessed foods, such as soda, ice cream, breakfast cereal, and prepackaged meals.
Those sounding the alarm about the potential harmful effects of UPFs are particularly concerned about their consumption by young people. The National Health and Nutrition Examination Survey showed that from 1999 to 2018, highly processed foods accounted for the majority of energy intake in those aged 2-19 years.
One of the most commonly used additives in UPFs, the artificial sweetener aspartame, garnered headlines this summer when the World Health Organization classified it as a likely carcinogen in humans. Aspartame is used in thousands of products, from soda to chewing gum to chewable vitamins.
The U.S. Food and Drug Administration strongly disagreed with the WHO’s position and is sticking by its recommended daily limit of 50 mg/kg of body weight – equivalent to 75 packets of the sweetener Equal – as safe for human consumption.
“Aspartame is one of the most studied food additives in the human food supply,” FDA officials said in a statement, adding that the agency found “significant shortcomings” in the studies the WHO used to justify the new classification. “FDA scientists do not have safety concerns when aspartame is used under the approved conditions.”
Increased attention to consumption of UPFs in general and aspartame particularly in recent years has yielded several studies pointing to the foods’ association with compromised brain health.