- A study found links between 32 health problems and eating ultra-processed foods.
- The link was stronger for some problems than others, such as depression and type 2 diabetes.
Ultra-processed foods have been linked with a higher risk of developing 32 health problems in a study. But experts say that they don't need to be cut out of our diets entirely.
The research, published in The BMJ on Wednesday, was based on 45 existing studies that assessed the potential health effects of ultra-processed foods, involving over 9.8 million participants in total. The studies looked at the amount of UPFs participants ate and if they developed any health problems.
This is the latest study to look at the potential health risks of UPFs, which have become a concern as they make up more and more of our diets. So far, research suggests that UPFs are not as healthy as whole foods such as vegetables, whole grains, and beans, but the US government's dietary guidelines don't recommend cutting them out.
The review defined UPFs as industrially produced foods made from chemically modified ingredients and additives rather than whole foods, such as packaged snacks, carbonated soft drinks, instant noodles, and readymade meals.
None of the studies were funded by or associated with ultra-processed food manufacturers.
UPFs were linked to health problems such as cardiovascular disease and depression
The review found links between consuming UPFs and 32 health issues, including a higher risk of dying in general, as well as cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic problems.
According to a press release, a 10% increase in UPF consumption was tied to a 12% higher risk of developing type 2 diabetes.
Seven studies found a direct link between eating more UPFs and the risk of colorectal cancer, and a further six studies found that the risk of developing cardiovascular diseases, which include heart attacks and coronary heart disease, increased the more UPF participants consumed.
Other health problems linked to eating a lot of UPFs included:
Hypertension (high blood pressure)
Obesity, especially abdominal
Death from any cause
Anxiety
Depression
Sleep problems
It also found limited evidence for associations between higher UPF consumption and asthma, non-alcoholic fatty liver disease, and other cancers, including breast, prostate, and pancreatic cancers, chronic lymphocytic leukemia, and central nervous system tumors.
Some UPFs may be beneficial for our health, so more research is needed
Evangeline Mantzioris, program director of nutrition and food sciences at the University of South Australia, who was not involved in the study, said in a statement: "this research highlights the importance of people limiting their intake of UPF and replacing it with whole foods."
However, the researchers categorized the associations for most health problems as "low" or "very low" in credibility.
Plus, the team acknowledged that not all UPFs appear to affect health in the same way. In one study, UPFs were generally associated with a higher risk of type 2 diabetes, but certain sub-categories of UPF were actually associated with a lower risk of type 2 diabetes, such as ultra-processed cereals, dark/wholegrain bread, packaged sweet and savory snacks, fruit-based products and yogurt, and dairy-based desserts.
The authors of the study recommended that the public should be encouraged to eat fewer UPFs, but dietitians have previously told Business Insider it's unwise to completely cut out UPFs, as they can be an easy and cheap way to get calories and nutrients.
Instead, dietitian Taylor Grasso previously told BI it's best to aim for an 80:20 ratio of whole to processed foods to help people eat healthily but not obsess over food.
Gunter Kuhnle, professor of nutrition and food science at the University of Reading, UK, who was also not involved in the study, said in a statement that as the results discussed in the review are based on very weak data and don't touch on the causes of the health problems mentioned, they don't justify any changes in dietary recommendations.
It's unclear why UPFs are linked to so many health problems
The review suggested several reasons why UPFs might be linked to health problems.
Firstly, a person who eats a lot of UPFs may have a poor diet in general, which can lead to health problems. Or, it could be that UPFs replace nutritious foods in people's diets.
The additives in UPFs, such as non-sugar sweeteners, emulsifiers, and colorants, could also cause health issues. The authors pointed out that sweeteners, for instance, have been classified as "possibly carcinogenic" by the International Agency for Research on Cancer, although at levels higher than most people would consume.
It could also be that the industrial processing involved in producing UPFs or the packaging they tend to come in could contaminate the foods with harmful substances.
But, the authors acknowledged that they don't know for sure why UPFs cause these issues, and that further research is needed.