We all know that processed foods aren’t the healthiest choice.
But four recent studies, including one this week, indicate that some of these non-nutrient-dense options, often referred to as ultra-processed foods, may increase the risk for a shorter life as well as poor mental health outcomes.
The modern grocery store is filled with many choices for consumers to consider. Some choices (such as fruits and vegetables) are obvious options that will benefit health and longevity. In comparison, others may provide us with calories, but no real nourishment.
For starters, it’s important first to define the differences in our food choices when it comes to processing:
- Whole foods are foods that are intact and have gone through either no processing or minimal processing. An example would be steel-cut oats (no processing) or old-fashioned oats (some processing to account for quicker cooking). A key indicator of whole foods is that most to all of their nutrient density (vitamins, minerals, fiber) remain intact. Examples include whole fruits or vegetables, raw nuts and seeds, intact grains such as quinoa or wild rice, dry beans and legumes, fatty wild fish, lean poultry or meat, and yogurt.
- Processed foods are those that have undergone some processing from their original and natural state. This could include the addition of additives such as salt or sugar. They may also contain additives to ensure freshness. Examples may include fruit juice, refined flour, canned beans and fish, fresh bread, cheese and even pre-cut vegetables.
- Ultra-processed foods are foods that have undergone an extensive transformation of the original food and often contain only extractions of the food. A 2019 commentary in the journal Public Health Nutrition defined ultra-processed foods as “industrial formulations of processed food substances (oils, fats, sugars, starch, protein isolates) that contain little or no whole food and typically include flavorings, colorings, emulsifiers, and other cosmetic additives.” Examples may include processed reconstituted meat products, potato chips, frozen French fries, candy, store-bought cookies, soft drinks, refined grain pretzels, commercial bread, sweetened breakfast cereals, and baking mixes.
Ultra-processed foods are foods that have undergone an extensive transformation of the original food and often contain only extractions of the food.
What do studies show about the regular consumption of ultra-processed foods?
A handful of corn chips during a football game or a store-bought cookie after dinner won’t make a huge difference in your overall health. However, when these foods become staples in your diet, research shows that adverse physical and mental health implications may arise.
Ultra-processed foods may lead to poor mental health outcomes
A 2022 cross-sectional examination in the journal Public Health Nutrition found that individuals who consumed the greatest amount of ultra-processed foods were significantly more likely to report mild depression, as well as more mentally unhealthy and more anxious days per month. The authors noted that the associations with adverse mental health outcomes and ultra-processed foods might derive from the greater presence of biologically active food additives and low-essential nutrients.
Another study published in the August 2023 issue of the Journal of Affective Orders found that high consumption of ultra-processed foods is associated with depressive symptoms, especially in people with obesity.
Ultra-processed food intake may increase the risk of cancer, as well as all-cause and cardiovascular risk mortality
Recent data, derived from three large prospective cohort studies and published in the British Medical Journal, found that men (but not women) who consumed a large amount of ultra-processed foods had a 29% greater risk of colorectal cancer than men who consumed smaller amounts. The men who consumed the highest amount of ultra-processed foods consumed mostly ready-to-eat products derived from meat, poultry or fish. Another recent study in the BMJ found that food processing (and consumption of foods highly processed) was linked with higher mortality risk, especially from cardiovascular disease.
Studies show that ultra-processed foods may also lead to adverse health outcomes due to associations related to excess consumption with obesity, heart disease and nonalcoholic fatty liver disease.
A study published Monday in the American Journal of Preventive Medicine linked the consumption of highly processed foods to early death. The study estimated that in 2019, the deaths of as many as 57,000 Brazilian people between the ages of 30 and 69 were linked to ultra-processed food.
How to avoid ultra-processed food
Best-selling author Michael Pollan defined food as something that comes from nature, is fed from nature and eventually rots. This is perhaps the first high-level manner in which to determine whether a food is ultra-processed or not. Ultra-processed foods will tend to give themselves away by other factors as well:
- A long list of ingredients that are not native to the average kitchen or that are not ingredients that the average consumer can understand. This may include colorings, preservatives or other additives meant to increase palatability.
- Foods that have been stripped of fiber, or foods that contain large quantities of calories, fat, sugar or salt may also be key indicators. This indicates that the product is dense in energy, but not in nutrients.
- Most ultra-processed foods are low in cost, convenient and easy to prepare. Studies also indicate that processed foods are typically those that are hard to stop eating, often referred to as hyper-palatable.
How dangerous are ultra-processed foods? Moderation is a key
Completely avoiding all ultra-processed foods may not be realistic for everyone. So just how much is it OK to eat? And when does the amount consumed hit a level that it will start to affect your health?
Assessing the processing level of a food and knowing just how much we should avoid certain foods can be confusing. And it can vary even among different sources of the same food. For example, there is a difference between a burger cooked at home versus a burger bought frozen from the grocery store versus a burger purchased from a fast-food restaurant. The three may vary greatly in their processing. Processing of general snack foods may vary as well based on brand and practices. Plus, total avoidance may be challenging for some individuals based on budget, accessibility and. time constraints.
The recent data on ultra-processed foods, however, clearly show that the greater the consumption, the greater the risk. Therefore, making a frozen pizza for dinner, having pretzels or crackers for a snack, or having a few slices of bacon on a Sunday morning is not what researchers have found to be the culprit of early death. Rather, it’s when these foods are significantly more prevalent than nutrient-rich whole foods. As with most areas of nutrition, further studies are needed to truly assess all the complexities surrounding our dietary choices and our health.
Ultra-processed foods are not going away anytime soon, but consuming less of them may benefit your overall health. A safe rule of thumb is to make 85% of your diet nutrient-dense, and consider the remaining 15% percent your allowance for everything else. This is how we can start to truly change our nutrition story by striving for a sustainable healthy diet — not perfection.