New research suggests that the nutritional quality of food may be more important than the degree to which it is processed. The study, analyzing data from over 200,000 participants in three large US studies spanning from the 1980s to the 2020s, found that products such as canned beans, plant-based dairy, and vitamin-fortified breakfast cereals can still contribute to a healthy diet.
Study Details and Findings
Participants were grouped into four categories based on their plant-based eating habits: healthy/ultra-processed (e.g., plant-based milk and yoghurts), healthy/minimally processed (e.g., fresh fruit and nuts), unhealthy/ultra-processed (e.g., fast food and fizzy drinks), and unhealthy/minimally processed (e.g., fruit juice, potatoes, white rice). During follow-up, 26,209 people developed cardiovascular disease, around 21,000 developed type 2 diabetes, and 55,493 died.
The study found that the risk of death, diabetes, and cardiovascular disease varied depending on the overall quality of a person's diet. Those who ate more healthily had a lower risk, regardless of whether food was ultra-processed or minimally processed.
Expert Comments
Xiaowen Wang, a postdoctoral research fellow in the department of nutrition at Harvard TH Chan School of Public Health, said: “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.”
Ms Wang added: “A healthy plant-based diet rich in whole grains, fruits, vegetables, nuts, legumes and healthy plant oils is beneficial, even if it includes some processed foods.” She also warned: “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.”
She concluded: “People should prioritise the quality of foods rather than focusing solely on the level of processing. Aim for more nutrient-dense, high-quality foods to help lower your risk of chronic diseases.” The findings will be presented at Nutrition 2026, the flagship meeting of the American Society for Nutrition, on July 28.
