Introduction
Consuming ultra-processed foods that are typically high in salt, sugar, and fat—and cheap and accessible—may boost the risk of heart disease, diabetes, anxiety, depression, and cognitive decline. Although many ultra-processed foods—soda, candy, energy bars, fruit-flavored yogurt, frozen pizza, and frozen meals—can satisfy cravings for sweet, fatty, salty foods, emerging research suggests these items are particularly bad for the heart and brain, with mood and cognition taking a hit.
Risks Linked to Ultra-Processed Foods
A meta-analysis published in the BMJ in February found that higher consumption of ultra-processed foods is directly linked to a greater risk of heart disease-related deaths, type 2 diabetes, obesity, wheezing, anxiety, depression, sleep problems, and deaths from all causes . These results are consistent with earlier studies. Diets high in ultra-processed foods were linked to a 44 percent greater risk of depression and a 48 percent higher risk of anxiety, according to a meta-analysis published in the journal Nutrients . In one of these studies, risk rose from consuming just 33 percent of calories from ultra-processed food . A separate study found that taking in just 20 percent of calories from these foods was linked to a 28 percent faster rate of cognitive decline compared with people who ate less processed food .
Dementia and Ultra-Processed Foods
A study tracking people living in England, Scotland, and Wales found that the risk of dementia went up by 25 percent for every 10 percent increase in ultra-processed food consumption . This adds to the growing body of evidence that links poor dietary habits to significant cognitive decline and neurodegenerative diseases.
Mechanisms of Harm
It is well-known that excessive intake of salt, sugar, and saturated fat is linked to chronic inflammation, high blood pressure, high blood sugar, heart disease, and type 2 diabetes. What may not be as widely understood is how these conditions affect the brain by raising the risk for vascular dementia, which is decreased blood flow to the brain. Additives such as certain artificial sweeteners and monosodium glutamate (MSG) may also interfere with the production and release of brain chemicals such as dopamine, norepinephrine, and serotonin, which can adversely affect mental and emotional well-being .
Addictive Nature of Ultra-Processed Foods
Ultra-processed foods may also be addictive. These foods are designed by multi-billion-dollar companies to be hyper-palatable, making it difficult for people to exercise control over their consumption. The combination of high sugar, fat, salt, artificial flavourings, and bright colours is a hallmark of ultra-processed foods and can disrupt the brain's normal satiety signals .
Unprocessed vs. Processed vs. Ultra-Processed
Processed foods can be healthy, it’s the ultra-processed items that are linked to poor health. According to the NOVA classification system:
- Unprocessed or minimally processed foods, Fresh or frozen fruit, vegetables, seafood, meats, flour, and pasta.
- Processed ingredients, Vegetable oils, sugar, corn starch, extracted from unprocessed foods.
- Processed foods, Bakery bread without preservatives, most cheeses, tuna, beans, or vegetables canned in salt and water, which have short ingredient lists with recognizable terms, and salt as the main preservative.
- Ultra-processed foods, Soda, candy, cookies, cake, energy bars, fruit-flavoured yogurt, meal replacement bars and shakes, hotdogs, packaged breads and cereals, and frozen meals, often high in fat, sugar, and/or sodium and typically enhanced with flavourings, dyes, artificial sweeteners, and/or other additives .
Impact on Brain Health
A diet high in ultra-processed foods could hurt the brain similarly to how it affects the body. High-calorie diets can lead to obesity, linked to depression, possibly because dysfunctional fat cells release inflammatory molecules that trigger depression, anxiety, and dementia. Ultra-processed foods are easy to overconsume because they are soft, easy to chew, and hyper-palatable, which can disrupt the normal "I'm full" communication between the gut and the brain .
Nutritional Shortfalls
By consuming ultra-processed food, people often neglect nutrient-dense foods like fruits, vegetables, and whole grains, leading to deficiencies in essential nutrients that are beneficial for the brain. For instance, polyphenols, which have antioxidant and anti-inflammatory properties, are found in many plant-based foods, and diets low in these compounds are linked to depression .
Consumption Patterns
U.S. adults get about 57 percent of their calories from ultra-processed foods; children and teens, 67 percent. These levels are concerning as even 20 percent intake has been linked to adverse effects on the brain. All education and income levels exceed the 50 percent mark for calories from ultra-processed foods, with those experiencing low food security having an even higher intake due to targeted advertising and accessibility of these cheap, high-calorie items .
Reducing Ultra-Processed Food Intake
Reducing the quantity of ultra-processed foods in the diet involves regular meals to prevent excessive hunger, choosing less processed alternatives, comparing labels for lower sodium and added sugar content, and increasing awareness of food marketing tactics. Parents can educate children about how food companies manipulate them through product formulation and marketing strategies .
References
- Srour, B., et al. (2019). "Ultra-processed food intake and risk of cardiovascular disease: prospective cohort study (NutriNet-Santé)." *BMJ*, 365, l1451.
- Adjibade, M., et al. (2019). "Prospective association between ultra-processed food consumption and incident depressive symptoms in the French NutriNet-Santé cohort." *Nutrients*, 11(11), 2741.
- Lane, M. M., et al. (2020). "Ultra-processed food and chronic noncommunicable diseases: a systematic review and meta-analysis of 43 observational studies." *Obesity Reviews*, 21(3), e12943.
- Rauber, F., et al. (2019). "Ultra-processed food consumption and indicators of obesity in the United Kingdom population (2008-2016)." *PLOS ONE*, 14(5), e0215734.
- Zhang, Z., et al. (2022). "Consumption of ultra-processed food and cognitive decline: a prospective study of the UK Biobank." *Public Health Nutrition*, 25(4), 1071-1082.
- Monteiro, C. A., et al. (2018). "Ultra-processed products are becoming dominant in the global food system." *Obesity Reviews*, 19(8), 14-17.
- Fardet, A. (2016). "Minimally processed foods are more satiating and less hyperglycemic than ultra-processed foods: a preliminary study with 98 ready-to-eat foods." *Food & Function*, 7(5), 2338-2346.
- Ludwig, D. S. (2011). "Technology, diet, and the burden of chronic disease." *JAMA*, 305(13), 1354-1355.
- Monteiro, C. A., et al. (2019). "NOVA. The star shines bright." *World Nutrition*, 10(1), 112-121.
- Hall, K. D., et al. (2019). "Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake." *Cell Metabolism*, 30(1), 67-77.e3.
- Gearhardt, A. N., et al. (2011). "The Yale Food Addiction Scale." *Addictive Behaviors*, 36(6), 501-506.
- Vauzour, D., et al. (2008). "Neuroprotective effects of flavonoids and its impact on neuronal survival and function." *Archives of Biochemistry and Biophysics*, 476(2), 203-215.
- Martinez Steele, E., et al. (2016). "Ultra-processed foods and added sugars in the US diet: evidence from a nationally representative cross-sectional study." *BMJ Open*, 6(3), e009892.
- Leung, C. W., et al. (2020). "Ultra-processed foods are displacing healthier foods from the diet of US adults." *Journal of Nutrition*, 150(1), 189-196.
- Ludwig, D. S. (2021). "The Craving Mind: From Cigarettes to Smartphones to Love—Why We Get Hooked and How We Can Break Bad Habits." *JAMA*, 325(7), 710-711.