Do ultra-processed foods make you age faster?

By Gretchen McKay / Pittsburgh Post-Gazette

You don’t need an advanced degree in food science to know on a gut level that ultra-processed foods aren’t good for you, and filling up on them day in and day out probably isn’t great for your overall health. 

While they certainly satisfy our bodies’ cravings for fat, sugar and carbs, and are sometimes cheaper than the fruits, vegetables and other whole foods we know are good for us, salty snack foods, processed meats and sugary beverages are typically high in high-fructose corn syrup, unhealthy saturated fats and salt, and chock-full of calories that lack real nutrition. 

According to the American Heart Association, a diet full of ultra-processed foods not only can lead to chronic diseases like obesity, hypertension and type 2 diabetes, but also may also be linked to an increased risk of heart and cardiovascular disease, certain cancers and stroke.

But do they also, as some recent studies suggest, including one featured in the journal Nature Medicine in May, make people grow older faster than those who follow a healthier diet?

The answer is a definite “maybe,” in that researchers don’t know for sure, said Karen Harouse-Bell, assistant professor of nutrition and dietetics at Seton Hill University.

For starters, it matters how you define “ultra-processed.” Does it mean the food includes a certain amount of additives and preservatives? Was it made using industrial techniques and processes? Or is it a food that simply includes minimal or no whole foods?

It also depends on whether the study shows causation between these not-good-for-you foods and accelerated aging, or a correlation. The former implies one action leads to another, while the latter means there is only an association between the two. 

There is no doubt that people are eating way too much of some ultra-processed foods; according to a 2022 Smithsonian Magazine article, for instance, Americans gobble down about 1.85 billion pounds of potato chips each year, or more than 6½ pounds per person. That said, there are very few studies that evaluate ultra-processed foods leading to early aging directly, said Karouse-Bell.

And most, she said, have been observational studies where people report what and when they ate that cannot definitively prove cause and effect because there are so many confounding variables.

That means the suggested association between heavily processed foods and biological aging — where our cells are in the aging process versus the number of years lived — could also be due to other factors such as a lower intake of flavonoids or phytoestrogens, which are found in fresh fruit and vegetables, or higher exposure to chemicals during food packaging.

“Some studies show these associations, but as I tell my students, there’s no way to know if the association is because of ultra-processed foods or another possible reason,” she said. “For instance, people who eat more ultra-processed foods may not be as active [as those who eat fewer] or also eat less fruits and vegetables.”

Even the multi-generational Dutch LifeLine Cohort Study, which studied health and diseases passed down within families, concluded that further research is needed to fully understand the complex relationship between diet and lifestyle factors that will help unravel the determinants of healthy aging.

“It’s a very interesting topic, looking at how Americans eat,” said Harouse-Bell. “But it’s a mistake to blame the ultra-processed food themselves for health problems, since it’s not so much the foods themselves as the overconsumption” of high-calorie fatty and sugary foods, and acceptance by the public that they’re “normal” foods.

According to the Centers for Disease Control and Prevention, between 60-70% of the American diet now consists of highly or ultra-processed food,  she noted, “and that is just shocking to me.”

Food, she added with a sigh, “is meant to nourish us, and deliver all the nutrients we need” on a daily basis. 

What, exactly, does ‘ultra-processed’ mean?

Food processing is any deliberate change made to a food from the time of origin to the time of consumption

While there is no standard agreement on what “ultra-processed” means, Karouse-Bell says the NOVA classification system developed by researchers at the University of São Paulo in Brazil provides researchers with some basic tools (though its functionality remains largely unexplored). It assigns foods to one of four groups based on how heavily they are industrially processed.

Group 1 foods contain unprocessed or minimally processed foods. They include the edible parts of plants or animals that have been taken straight from nature or that have been minimally modified or preserved by, say, drying, crushing, grinding, refrigeration or vacuum-packing. 

Group 2 foods contain “processed culinary ingredients” such as oils, butter, sugar and salt, which are produced from Group 1 foods and used to make freshly prepared drinks, dishes and meals. Examples include cooking oils, sweeteners like maple syrup or honey, spices and condiments like ketchup and mustard. 

Group 3 includes “processed foods” that have undergone specific alterations during processing to prevent spoilage, enhance flavor or make them more convenient. Think freshly baked breads, processed cheese slices, canned vegetables or breakfast cereal.

Group 4 foods, the “ultra-processed,” are the least nutritious of the bunch. They typically contain little or no whole foods, are ready-to-consume or heat up, and are fatty, salty or sugary and depleted of dietary fiber, protein and micronutrients. Group 4 foods also are the only ones to include emulsifiers, flavor enhancers, anti-caking agents, high-fructose corn syrup, hydrolyzed proteins and other additives. Here’s where you’ll find soft drinks, sweet or savory packaged snacks, frozen pizza, meat products like hot dogs and chicken nuggets and frozen microwave dinners. 

Say you take an apple, said Karouse-Bell. It’s unprocessed if you eat it out of hand, but is considered processed if you treat it with ascorbic acid after cutting it into pieces to prevent browning. And ultra-processed apple food would include that boxed, shelf-stable apple pie you might take to a picnic or an apple drink that includes high-fructose corn syrup.

Even though the word itself can have negative connotations, processing is not necessarily a bad thing, said Karouse-Bell.

Some foods, like whole grains and milk, have to be modified from their natural state to make them easier or safer to eat or be served at peak freshness. Fish is often frozen at sea right after being caught to preserve quality, milk is pasteurized to kill harmful bacteria, canned tomatoes are heated to prevent spoilage, and salad greens and fruits and vegetables are chopped into bite-sized pieces for the sake of convenience.

Also, sometimes the nutritional positives of a food outweigh the negatives of its processing. For example, yogurt is considered an ultra-processed food because it contains sweeteners, thickeners and preservatives. But it’s also an excellent source of bone-building calcium, protein (which is crucial for aging women) and probiotics for gut health. 

For some consumers, it also can be simply a matter of economics. Ultra-processed foods are generally cheaper than fresh, unprocessed foods, making them a more budget-friendly option at the grocery store. 

Not everyone has the financial resources or pantry space to buy and cook fresh every day or week, Karouse-Bell noted.

“Maybe all they have [access to] is canned green beans” or jarred spaghetti sauce, she said. Canned vegetables are better than no vegetables at all, especially if you take care to first wash off the excess salt. 

“There are times in life where you do what you can do.”

Ultra-processed foods are also heavily marketed and more widely available at even the smallest convenience store. And because their flavor is enhanced with chemicals, they are often highly addictive and craveable. Lays’  "Betcha can't eat just one" tagline is famous for a reason. 

Shop more wisely

What we should be focusing on instead, said Harouse-Bell, is the importance of eating as many unprocessed and minimally processed foods as possible.

That includes actually reading labels when you’re at the grocery store to determine how processed the contents are, and opting for one-ingredient foods that are closer to the source— like rice, meat, beans and pasta.

“If [the label] is becoming more and more lengthy, that is what you’re getting,” she said. “The more steps, the further away you’re getting from whole foods.”

For breakfast, healthy choices would include breads that contain whole grain flour as a main ingredient, breakfast cereals with fewer added sugars, oatmeal, shredded wheat or diced fruit.

Lunch and dinner could be built around fresh poultry or fish, dried or low-sodium canned legumes, whole grains like brown or wild rice, and frozen vegetables that aren’t swimming in a butter or cream sauce. 

Fresh fruits or unsweetened apple sauce are also good choices, she said, along with low-sugar yogurt and nuts for snacks or dessert.

“There is a lot of confusion about what to eat,” Karouse-Bell said, “but it’s basically what we learned in grade school about MyPlate’” she said. The essentials haven’t changed. “We’ve just deviated from it.”

Especially as we grow older, consumers need to realize you gain weight as you age, because you just don’t need the same number of calories to maintain a healthy weight.

Which brings us back to the negatives of ultra-processed foods. 

A lot of times they’re tasty and scratch a certain culinary itch that’s definitely worth the culinary splurge. But because they’re lacking in nutrients, it’s easy to consume the calories and then we gain weight.

“We have normalized these types of food to be part of our typical intake,” she said. “But regardless of age, it’s never too late to make a healthy change.”