Ultra-Processed Foods May Be Even Riskier Than You Think

Diets high in ultra-processed foods are consistently linked to many chronic diseases, including cancer, cardiovascular disease, diabetes, and mental-health conditions, according to an expansive new analysis of health outcomes in a global population.

“Earlier studies have already linked ultra-processed food to some diseases, but mostly one condition at a time, in smaller populations,” says lead author David Xiao Liu, MD, a cardiologist and research fellow with Duke-NUS Medical School in Singapore.

“By pooling worldwide data from 51 studies, we were able to build much stronger evidence and model a dose-response relationship, essentially showing how risk changes as people eat more or less ultra-processed food.”

What Makes Ultra-Processed Foods So Bad?

Ultra-processed foods are generally defined as ready-to-eat items (such as packaged potato chips and sodas) or heat-and-serve products (such as frozen pizzas and microwavable dinners) that have undergone extensive industrial processing.

“They tend to be higher in calories and higher in refined carbohydrates, sodium, added sugars, and unhealthy fats while being lower in fiber and beneficial micronutrients,” says Samantha Flanagan, DO, assistant professor with the department of clinical family and community medicine at Temple University’s Lewis Katz School of Medicine in Philadelphia.

The study authors describe the mix of additives in ultra-processed foods as having a “cocktail effect.” “When several additives combine and interact inside the body it may add up to a bigger effect than you’d expect from each ingredient individually,” says Dr. Liu.

The study authors add that compounds that may form during food processing, such as acrylamide (a contaminant formed in heat-treated processed foods) and acrolein (generated during fat heating), have been associated with a higher incidence of cardiovascular disease.

Small Amounts Push Various Health Risks Higher

The research analysis, which was published this week in the journal Family Medicine and Community Health, looked at 51 studies representing more than 8.8 million adults from the Americas, Europe, and Asia, and Oceania, ranging in age from 24 to 77.

The analysis found that each additional 100 grams (3.5 ounces) of ultra-processed food a person consumed per day was linked with a 14 percent higher chance of cardiovascular events, 4 percent higher odds of cancer, 2 percent rise in the likelihood of metabolic syndrome/diabetes, and a 3 percent higher risk of early death from any cause.

For Sandra Zhang, RDN, of the Frances Stern Nutrition Center at Tufts Medical Center in Boston, the results are very persuasive due to the large sample size and inclusion of so many studies.

“The biggest limitations are that diet was self-reported and the studies were observational, so we can’t say ultra-processed foods directly caused these health problems,” says Zhang, who was not involved in the research.

Making Moves to Improve Diet

To improve your diet, nutrition experts advise the following:

• Read food labels. “Check package labels for ingredients that don’t sound like they would be found in a typical kitchen,” says Zhang. Also take note of added sugar (fructose and corn syrup) and sodium.
• Shop the perimeter. “Most of the ultra-processed foods live in the middle of the store — in the cookie, cracker, cereal, and soda aisles,” says Lindsey Smith Taillie, PhD, a professor in the nutrition department at University of North Carolina’s Gillings School of Global Public Health in Chapel Hill, who was not involved in the new research analysis. “Sticking to the perimeter where the fruits, veggies, plain meats, and dairy are helps, along with shopping for shelf-stable staples like beans, rice, and pasta,” she recommends.
• Seek out dietary advice from a professional. “Many commercial insurance companies cover some level of dietitian services for free,” says Flanagan. “If you have access to something like this it can be a great way to learn more about the types of foods you are eating and how to decrease ultra-processed and less healthy foods in your diet.”