McMaster study links ultra-processed food to range of health risks and calls for more affordable whole foods

New research out of McMaster University in Ontario has directly linked consumption of ultra-processed foods – a category that includes not just traditional junk foods, but items marketed as healthy as well – to several health issues.

The paper was written by McMaster University kinesiology researchers and published in the peer-reviewed journal Nutrition and Metabolism on Wednesday.

The researchers found that consumption of ultra-processed foods (UPFs) was linked with correlating levels of high blood pressure and cholesterol, and was not affected by an individual's age, size and level of activity.

Higher consumption of these processed foods is also linked to higher levels of triglycerides, "a type of fat found in the blood which, in high amounts, contributes to risk of heart disease, stroke and other diseases," study co-author and PhD student Angelina Baric told CBC Hamilton. 

She also said the research shows that processing foods changes how available the foods' nutrients are to the body and that higher consumption meant higher risk of health issues in every demographic researchers looked at.

Many links between the consumption of these foods and the cardiometabolic risk factors "remained significant even after adjusting for [Body Mass Index], suggesting that ultra-processed foods may influence health through mechanisms beyond weight gain, such as inflammation, insulin resistance, and poor metabolic regulation – all well-established predictors of heart disease and type 2 diabetes," McMaster said in a press release.

"The associations persisted even after adjusting for physical activity, smoking, the total amount of food consumed and socioeconomic factors including income and education," said the release.

Ultra-processed foods are typically considered pre-packaged items that contain "ingredients you wouldn't use in home cooking, such as additives, emulsifiers, flavour enhancers and colours," Baric said. 

Examples include potato chips, hot dogs, deli meat and frozen foods. Baric said these foods often contain "substances that are extracted from whole foods rather than whole foods themselves."

They are often high in sodium, sugar and saturated fat, she added.

Even seemingly healthy foods such as protein bars and breakfast cereal largely fall under this category, Baric said.

Her team's research found that people with lower incomes were likely to eat more of these foods, but she says those of higher socioeconomic status might be more likely to consume processed foods targeted at the wellness and workout markets, such as protein powder, protein bars or energy drinks.

"Those are also ultra-processed," she said. "There's still a lot of additives added to these foods."

The term "ultra-processed foods" is distinct from "processed foods," which typically refers to items with less than five ingredients, such as canned vegetables.