Nutrition is a comparatively new type of science. For example, the first vitamin was isolated and chemically defined in 1926 – less than 100 years ago! As nutrition science continuously evolves and research linking food to health outcomes increases, it’s natural to overreact to sweeping conclusions about not one food or nutrient, but many foods commonly consumed by most people. Recently, the media has been mentioning the phrase ‘ultra-processed foods’ – prompting another buzzword to add to your nutrition and health lingo.
Defining the term
By definition, a processed food is a food item that has had a series of mechanical or chemical operations performed on it, typically to change or preserve it. This can range from grinding meat and forming it into a burger patty to manufacturing tofu from soybeans. The term ‘ultra-processed’ was developed over ten years ago by researchers at the University of São Paulo, Brazil. The researchers defined the term as part of a proposed new classification of foods known as the NOVA classification, which categorizes foods according to the extent and purpose of food processing, rather than in terms of its nutritional composition. This is why, for example, breakfast cereals are included in the ultra-processed food category, even though they may contain whole grains or low-fat ingredients that could be a healthy choice in the diet. According to the NOVA system, ultra-processed foods are “…industrial formulations typically with five or more and usually many ingredients. Such ingredients often include those also used in processed foods, such as sugar, oils, fats, salt, anti-oxidants, stabilizers, and preservatives.” Further, ultra-processed foods are described as “convenient (durable, ready to eat, or heatable), hyper-palatable (extremely tasty), highly profitable (low cost ingredients), and designed to replace all other food groups with the aid of attractive packaging and intensive marketing.” While the term ‘ultra-processed’ may be popping up more in the media these days, this doesn’t indicate a new, extreme form of processing that consumers should avoid. In fact, ultra-processed foods may provide more benefits than you think.
What does nutrition research say?
In the spring of 2019, the British Medical Journal (BMJ) added fuel to the conversation around ultra-processed foods by publishing two observational studies, one of which linked consumption of ultra-processed foods to increased risk of cardiovascular disease (CVD), and another linking this food category to all-cause mortality. In the first study, researchers at the University of Paris monitored the diets of approximately 100,000 people twice a year for five years using the abovementioned NOVA classification system. The researchers then looked for associations between intake of ultra-processed food and risk of CVD, and found there was a 12% increase in the risk of CVD for every 10% increase in the amount of ultra-processed food consumed.
In the second study, researchers from the University of Navarra in Spain assessed the diets of almost 20,000 people annually over the course of 15 years (i.e. 1999 to 2014) using the NOVA system. After taking into account other confounding variables such as age, body mass index (BMI), and smoking history, the researchers concluded that there was a 62% greater risk of death for participants eating more than four servings of ultra-processed food a day compared to those eating the least amount of ultra-processed food.
What does this research mean?
While the findings from these studies are strengthened due to the large sample sizes, it’s important to remember that observational study designs do not demonstrate cause and effect. Further, linking ultra-processed foods to CVD is a complicated assumption, especially when multiple factors, including family history and other lifestyle choices, can contribute to disease development. Both unprocessed and processed red meats, for example, are associated with greater risk of developing CVD and type 2 diabetes compared to poultry, fish, or vegetable protein sources. Additionally, the definition of ‘ultra-processed foods’ was not adequately-defined in these studies and is not well-defined by the healthcare community. For example, some define ‘ultra-processed foods’ as “ready to eat, snack foods,” which could include dried fruit that can be a healthy snack.
Putting it All Together
Of course, if we review the definition of ultra-processed foods, it’s not surprising that excess consumption of such foods would likely cause such negative health outcomes. However, processed food intake alone is not a strong enough variable to link to disease development, and the definition and subsequent intake recommendations should be clearer for consumers to understand. It’s absolutely true that certain processed foods should be consumed less often and in smaller portions than others. With that said, it’s important to recognize that not all processed or ultra-processed foods provide the same benefits and nutrients, an aspect not considered by the NOVA classification system.
The greater body of nutrition research continues to emphasize the importance of a varied and balanced diet, of which processed foods are unavoidable and even often rich in nutrients. As there is no correlation between level of processing and the nutritional value of food, incorporating a rich variety of different foods in your diet is recommended. Such eating patterns are outlined by the Dietary Guidelines for Americans, which encourage intake of whole grains, fruits and vegetables, legumes, nuts, fish, poultry, and heart-healthy oil. Processed foods may include canned fruit, for example, that can be a healthy choice (when not packaged in syrup) and count toward a daily serving of fruit. Additionally, many processed foods are fortified with added fiber, vitamins, and minerals to support a healthy diet. Processed foods even include bread, which is often fortified with folic acid, a key nutrient to prevent birth defects. Fortified and processed foods not only aid in reaching the recommended daily values of key nutrients, but can also be formulated to reduce overall consumption of added sugars, fat, and sodium that, in excess, can contribute to the risk of chronic disease development.
Though new nutrition research and terminology is constantly the subject of media headlines, the widely-accepted and long-proven model for optimal nutrition remains the unsurprising, call it boring, truth – a balanced, varied, and colorful diet is the best way to ensure adequate intake of nutrients that support optimal health. No one is saying processed foods are not part of this equation.