Not all ultra-processed foods (UPFs) are detrimental to health, according to a major study that suggests the overall quality of a person's diet plays a more significant role in health outcomes than the level of processing.
The findings, presented at an annual meeting of nutrition experts in Maryland, indicate that foods like wholegrain breakfast cereals, plant-based milk and yogurt, whole grain bread, and canned fruit can be part of a healthy dietary pattern. Researchers analyzed data from over 200,000 U.S. adults to investigate the relationship between diet quality and the risk of heart disease, type 2 diabetes, and premature death.
While many UPFs are characterized by high levels of fat, sugar, and salt, and often contain artificial ingredients that may affect gut health, the study challenges the notion that all such foods are inherently harmful. The research aimed to disentangle the impact of overall diet quality from the degree of food processing.
"While many ultra-processed foods tend to be of poor nutritional quality and should generally be limited or avoided, processing itself is not inherently harmful," said Xiaowen Wang, a research fellow at Harvard T.H. Chan School of Public Health. "Advising people to universally avoid ultra-processed foods can lead to lower diet quality since healthy ultra-processed foods are beneficial and unhealthy minimally-processed foods are detrimental."
The study examined plant-based foods within participants' diets over four decades, from the 1980s to the early 2020s, to ensure fair comparisons. During this period, approximately half of the participants developed heart disease, type 2 diabetes, or died. The analysis revealed that individuals consuming healthier diets had a significantly lower risk of these adverse outcomes compared to those with poorer diets.
Crucially, the researchers found that the health benefits were similar whether the healthy diets consisted of ultra-processed or minimally processed foods. This suggests that the nutritional value of the food is a more critical factor than its processing level.
Traditional food classification systems, such as the Nova system, do not always account for nutritional value, potentially labeling nutritious UPFs as unhealthy while categorizing some less nutritious, minimally processed foods as acceptable. Experts recommend that individuals prioritize nutrient density and food quality over solely focusing on the degree of processing.
Conversely, the study confirmed that certain UPFs remain poor dietary choices, including fast-food meals, chips, fizzy drinks, packaged desserts, and snack foods like crisps and chocolate bars. Minimally processed items like white rice, fruit juice, and homemade desserts made with refined flour and sugar can also be unhealthy. The consensus among experts is that the public should focus on the overall dietary pattern rather than an exclusive avoidance of processed foods.