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The topic of ultra-processed foods (UPFs) is generating hot debate—and more than a little confusion—not only with the public but among scientists. Some studies suggest that UPFs are linked to adverse health effects like heart disease, cancer, and weight gain. Other research points to the benefits, and even necessity, of food processing to unlock some foods’ health attributes, feed a growing global population, and even reduce food waste. 

To untangle the issue from a scientific perspective, we turned to Mario Estévez García, professor of food science and biochemistry at University of Extremadura in Spain who researches the mechanisms behind the potential negative effects of UPFs. An internationally recognized expert on oxidation and antioxidants, Estévez García will present his most recent findings at a session dedicated to ultra-processed foods taking place just days from now at IFT FIRST: Annual Event and Expo in Chicago. His results will also appear in a Journal of Food Science special issue he is guest editing, due to be published this fall. 

Estévez García’s approach to ultra-processed foods is measured: “The arguments both from supporters and critics make sense, even if they appear contradictory,” he says. “They can complement each other, in fact.” Read on to get his perspective. 

Where do we go next with UPFs research?

While UPFs are associated with negative health outcomes, identifying the specific UPFs driving those associations is essential. But processing/ultra processing are necessary, and they are here to stay. They provide convenience, long shelf life, and why not: positive hedonic responses. They also provide a great opportunity to reduce food waste. So, both sides can be compatible, and we should work on both sides by, on the one hand, identifying harmful UPFs and, on the other, designing UPFs that meet scientifically based dietary recommendations, minimize health risks, and offer beneficial ingredients. 

Where should the scientific community be focusing its efforts right now?

It is essential to understand the potential harmful effects of UPFs beyond epidemiological studies. These studies establish a potential connection—a correlation—between UPFs and certain pathological conditions. But whether this connection is causal or not? This is wholly unknown in most cases. In other words, consumers eating more of some particular UPFs may be more prone to suffer certain diseases than those eating less of those UPFs. And yet, we cannot state that such UPFs are responsible for, or even connected to, such pathological conditions. To establish such a connection, we need to understand the pathophysiological mechanism: that is, which component or components of the UPFs are providing such negative health outcomes and how. This way, we can gain certainty about the connection between intake of such UPFs and the onset of the disease and take action on prevention. If we do not know the “enemy,” it is impossible to establish effective strategies to fight against it. 

Tell me more about the studies you’ve conducted on UPFs and summarize some of the key findings.

In my lab in Spain, we have been conducting mechanistic studies. We have found that certain types of processing seriously affect the digestibility of proteins and that such undigested proteins could display abnormal behavior in our gastrointestinal tract, leading to the impairment of the microbiota and the formation of certain toxic compounds. These studies have been performed initially on animals and will be carried out in humans as well. A relevant outcome from our research is that both plant-based and animal-based UPFs display similar issues. All of them have something in common: severe processing and high content of oxidized proteins. 

What would you say to vegans or vegetarians who may rely on plant-based UPFs?

Fruits and vegetables are essential components of our diet, and we all should eat more of them. But certain plant-based UPFs may not fall into that category anymore. The degree of processing and transformation of the raw ingredients may result in an ultra-processed food with little nutritional value and potential health risks. 

Are we adequately addressing peoples’ concerns about what ingesting processed food means for our health? What role should scientists play in this?

Consumers’ concerns are not being adequately addressed. One of the main reasons is lack of scientific knowledge and failed strategies on how to communicate what we know. It is important that scientists establish a clear definition of UPFs; this will help us communicate reasonable dietary recommendations. Another aspect I want to mention is conflict of interest. We need to keep conflict of interest out of the discussion surrounding UPFs. 

You are guest editing a special issue of Journal of Food Science on ultra-processed foods. What is the goal of the special issue and how does it advance scientific knowledge about UPFs? 

The main goal of this special issue is to provide readers with a compelling collection of papers related to ultra-processed foods written by authoritative experts and featuring some of the most recent mechanistic studies and original discoveries. These studies aim to increase our understanding of the proposed pathophysiological mechanisms of certain UPFs. I believe this is where we need to be concentrating our greatest efforts at this precise moment. 

In a highly anticipated IFT FIRST special session on ultra-processed foods, taking place Monday, July 15, at 3:15 p.m. CT, Estévez García will continue the conversation with Julie Hess, research nutritionist, Grand Forks Human Nutrition Research Center at USDA-Agricultural Research Service (ARS); Kevin Hall, senior investigator at National Institutes of Health (NIH); Youling Xiong, professor, Department of Animal and Food Science at University of Kentucky; and Anna Rosales (moderator), senior director, Government Affairs & Nutrition at IFT.

Are you coming to IFT FIRST? There’s still time—and members save big on registration. Reserve your spot today!   

To learn more about ultra-processed foods, check out this curated collection of IFT resources

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