New Evidence That Ultra-Processed Foods May Increase Cancer Risk

A study funded by the World Cancer Research Fund and Cancer Research UK and published in eClinicalMedicine, a Lancet open access clinical journal, provides new evidence of a link between ultra-processed foods (UPFs) and an increased risk of developing cancer.

A team from Imperial College London used UK Biobank data to assess the diets of 197,426 people between the ages of 40 and 69, who completed 24-hour dietary recalls during a three-year period. Ultra Processed Food consumption was expressed as a percentage of total food intake in grams per day and was assessed against the risk of developing and/or dying from 34 different types of cancer over a period of 10-years.

After the researchers adjusted for socio-demographic factors, physical activity, smoking status, and dietary factors, it was found that a 10% increase in consumption of ultra-processed food was linked to a 2% increase in being diagnosed with any cancer and a 6% increase in dying from cancer of any kind.

The researchers also found that, with each additional 10% increase in consumption of ultra-processed food, there was a 19% increased risk for ovarian cancer and a 30% increased risk of dying from ovarian cancer. There was also a 16% increase in risk of dying from breast cancer with each 10% incremental increase in consumption of UPFs.

According to the authors, this study is the “most comprehensive assessment for the prospective associations between ultra-processed food consumption and risk of overall and 34 site-specific cancer incidence and associated mortality.”

UPFs put quite simply, in addition to having undergone a significant amount of processing (which is not always a negative thing) contain ingredients chemically formulated from food-derived substances, and additives not typically found in a home kitchen. Foods such as sodas, hot dogs, frozen meals, flavored yogurt, packaged snacks and fast food typically contain preservatives to extend shelf life, stabilizers to preserve structure, artificial colors to make them appear more attractive, and artificial flavors, salt, sweeteners and fat to make them hyper-palatable.

According to Northeastern University’s Network Science Institute, 73% of the United States food supply is ultra-processed. Demand for these foods is driven by the fact that they are typically more affordable, heavily marketed, perceived as convenient due to long shelf life and often contain health claims on their packaging. But the most dangerous reason for why UPFs are so heavily consumed is their hyper-palatability— they are so pleasing to the taste buds that consumers are unable to stop eating them.

Whether they are marketed as “diet” or “health” foods, because they have been processed in such a way that they have a reduced amount of calories, UPFs are typically lower in nutritional value and contain ingredients that may be detrimental to health for a variety of reasons. Further, the additives, sweeteners and flavorings have proven to drive food addictions, which may cause over consumption of the very foods that are marketed as “diet.”

This is not the first study to establish a correlation between ultra-processed foods and cancer. A study published in The BMJ on August 31st 2022 found a 29% higher risk for developing colorectal cancer among men who consumed high amounts of ultra-processed foods as compared to men who consumed smaller amounts of UPFs.

Other studies have established a link between ultra-processed foods and cardiovascular disease, type 2 diabetes and obesity, among other ailments.

Given that packaging is never labeled according to degree of processing, it is easy to over-consume and become addicted to ultra-processed foods. In fact, January 2023 results of the University of Michigan National Poll on Healthy Aging found that 13% of adults age 50–80 showed symptoms of addiction to highly processed foods.

But how can the typical consumer differentiate between minimally processed foods (not all processing is bad) and ultra-processed foods?

With the extensive selection available in most modern supermarkets, an online tool called the TrueFood dashboard takes away the mystery surrounding the degree of processing in the most common brands of food products by giving each food item a food processing score, based on the percentile of processing as compared to other items in the same category.

Another more manual method of determining degree of processing is to look at the ingredients on the packaging. According to Professor Maira Bes-Rastrollo, a product that contains more than five ingredients is typically ultra-processed, as are foods with unrecognizable ingredients, and foods that are naturally found “fresh” but have a long shelf life.

These latest results are not good news for many health food companies, including vegan food manufacturers that market their plant-based or low calorie ultra-processed packaged foods as “good for you.”

Nearly half of all deaths due to cancer. The World Health Organisation and the Food and Agriculture Organisation have recommended the restriction of ultra-processed foods as part of a healthy and sustainable diet.