STEVE INSKEEP, HOST:
Many individuals are looking to reduce their consumption of ultra-processed foods. Research indicates these foods can elevate the risk of various health issues, including diabetes, heart disease, and even depression. The question then arises: how can we identify ultra-processed foods? Michaeleen Doucleff explores a potential answer.
MICHAELEEN DOUCLEFF, BYLINE: The method for detecting ultra-processed foods comes from Dr. Dariush Mozaffarian, who leads the Food is Medicine Institute at Tufts University.
DARIUSH MOZAFFARIAN: I refer to it as the water test.
DOUCLEFF: According to Dr. Mozaffarian, this water test is particularly effective for determining whether carbohydrates are ultra-processed. This includes items like bread, crackers, pretzels, puffed corn, and potato snacks.
MOZAFFARIAN: When people ask about ultra-processed foods, they often find grains and carbohydrates—like starches—most confusing. They want to know how to choose healthier versions.
DOUCLEFF: Essentially, he explains, you take a carbohydrate—like a piece of bread or a portion of a granola bar—and…
MOZAFFARIAN: Place it in a cup of water and check back in three or four hours. What does it look like?
DOUCLEFF: He specifies that the key is to observe whether or not it dissolves.
MOZAFFARIAN: If it remains largely intact, it’s likely that it will be digested slowly.
DOUCLEFF: Foods that are digested slowly can reach deeper into your gut, nourishing your microbiome, which is essential for good health. In contrast, ultra-processed carbohydrates break down quickly due to their manufacturing processes. Essentially, companies predigest the grains, corn, or potatoes.
MEROE MORSE: They are ground down into their individual components and then reassembled and bound together.
DOUCLEFF: That’s Dr. Meroe Morse from MD Anderson Cancer Center. She notes that placing an ultra-processed carbohydrate in water leads to it breaking down rapidly, mirroring what occurs in your digestive system.
MORSE: These items get digested very quickly, which can trigger a spike in glucose levels. When glucose spikes occur, insulin levels typically rise as well.
DOUCLEFF: Consistently experiencing such spikes can lead to insulin resistance and, eventually, diabetes. Therefore, when selecting carbohydrates, aim for those that maintain their structure in water. This is where the water test comes into play. I decided to test it with my daughter, Rosy.
ROSY: Hello.
DOUCLEFF: How old are you, Rosy?
ROSY: Ten.
DOUCLEFF: That’s right! We have two types of bread here: a French baguette purchased from the store and a whole wheat bread we made ourselves. What ingredients are in the baguette, Rosy?
ROSY: White flour, dextrose, wheat gluten.
DOUCLEFF: So, quite a few preservatives and additives. Now, we’re going to take similar-sized pieces of each type of bread and put them into a glass of water.
DOUCLEFF: After waiting three hours, Rosy and I examined the homemade whole wheat bread first.
Does it still look like bread?
ROSY: Yes.
DOUCLEFF: Is it still intact?
ROSY: Yes.
DOUCLEFF: Has it dissolved?
ROSY: No.
DOUCLEFF: Correct; it hasn’t dissolved. Our homemade bread has successfully passed the water test, indicating it is minimally processed. Now let’s check the baguette…
ROSY: Oh, wow.
DOUCLEFF: (Laughter).
ROSY: I can barely lift it. It feels like a sponge.
DOUCLEFF: …It has soaked up an enormous amount of water. Look at the glass; what’s happening inside?
ROSY: It’s dissolving.
DOUCLEFF: Exactly! The baguette did not pass the water test and is clearly ultra-processed.
ROSY: It’s kind of gross. Bread shouldn’t be like that.
DOUCLEFF: Precisely, it shouldn’t dissolve so swiftly in our bodies either.
For NPR News, I’m Michaeleen Doucleff.
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