Ultra-Processed Foods and Colon Cancer

**Brian Lehrer** (0:10)
It's The Brian Lehrer Show on WNYC. Good morning again, everyone. As we continue with this year's health convening, if you're just joining us for this and didn't hear the first segment, every year, WNYC hosts a health convening with support from the Alfred P. Sloan Foundation. The convening has typically been an opportunity for healthcare experts and practitioners to inform WNYC's health reporting in an off-the-air briefing and interaction. This is the third year that we're bringing it on to the air, as we've all decided it will be a service for you to hear the briefing too. This year's focus is on ultra-processed foods. You may have just caught our conversation with Dr. Kevin Hall, former senior investigator at the National Institutes of Health before the news, whose study linked ultra-processed foods to obesity. Now, we'll take a different tack and look at how some of these kinds of foods are correlated with an increased risk, specifically of colorectal cancer. Colorectal cancer is now the leading cause of cancer death in Americans under 50, with cases in that age group rising 3 percent per year, according to the statistics that have been published by the American Cancer Society's Colorectal Cancer Statistics 2026 report.
Our guest for this part of the conversation is Dr. Fang Fang Zhang, a Cancer Epidemiologist, MD, PhD, and Chair of the Division of Nutrition Epidemiology and Data Science at the Friedman School of Nutrition Science and Policy at Tufts University. In 2022, for example, she published a landmark study that found that men who consumed the highest levels of ultra-processed foods had 29 percent higher risk of developing colorectal cancer.
Women, different, and we'll get into it. Dr. Zhang's research has helped shape our understanding of why, what we eat, and how its process may be driving that trend. Dr. Zhang, thanks so much for some time today. Welcome to WNYC.

**Fang Fang Zhang** (2:20)
Thank you, Brian. I'm glad to be here.

**Brian Lehrer** (2:22)
Wondering listeners, as we get this conversation going, if any of you were diagnosed with or know someone who has or had colorectal cancer, and what conversations they were having or you were having with your doctors and care team about diet, did it come up at all? If you had an early onset scare, for example, were you able to make meaningful changes in your lifestyle in addition to treatment? But I wonder if it comes up, diet once you are diagnosed, or if the doctors just don't want to confront you with that, then they have to treat it. But Dr. Zhang, I'll start with your, and listeners 212-433-WNYC.
I should end that invitation with the phone number, shouldn't I? Call or text 212-433-9692.
Dr. Zhang, your 2022 study is one of the most cited papers linking ultra-process foods to colorectal cancer. I see you followed more than 200,000 healthcare professionals for over 25 years. So tell everybody briefly, what were you looking for and what did you find?

**Fang Fang Zhang** (3:38)
I'm sure. So in that study, we were trying to answer a question is, does eating more ultra-process food increase the risk of colorectal cancer? We know that ultra-process food make up a very large part of American diet.
And there's growing evidence linking these foods to a range of health issues like obesity, diabetes, heart disease, and premature death. So at that same time, that colorectal cancer is one of the cancers most strongly influenced by diet. We already know that higher intake of processed meat and lower consumption of fiber and whole grains increase risk of colorectal cancer. And many ultra-processed food tend to reflect those patterns, right? Many ultra-processed food contain processed meat and the low in fiber. So that really motivates us to look at this question in a large long-term study.
And we followed more than 200,000 men and women over about 25 years. And what we found is that among men, those who consume the highest amount of ultra-processed food had about 29 percent higher risk compared to those in the lowest intake. As you said, we didn't find the same association in women. And also I want to notice some differences in the type of ultra-processed food. For example, the higher consumption of processed meats, those as hot dogs, sausage, deli meats, and sugar-sweet beverages, were linked with higher risk in men. And in women, we saw higher risk related to certain ready-to-eat mixed dishes like pizza. On the other hand, we found some foods like yogurt, were actually associated with a lower risk in women.

**Brian Lehrer** (5:26)
Even though you consider yogurt a processed food?

**Fang Fang Zhang** (5:30)
Well, it depends on what type of yogurt. So the yogurt that's just plain, just made of milk and cultures, they're not considered ultra-processed. They're considered to be minimally processed. However, the yogurt with added sugar and other additives, like stabilizers, they are considered ultra-processed.