Lisa Andrews
Key Takeaways
- Scientists have classified foods into four groups (known as the NOVA Classification) based on how processed the foods are and they use this classification system in scientific research.
- Researchers have found that a higher intake of ultra-processed foods (UPF) increases the risk of developing many types of cancer, including colorectal, breast and pancreatic cancers.
- AICR’s Cancer Prevention Recommendations advise choosing more vegetables, fruit, legumes and whole grains, and fewer fast foods and ultra-processed foods loaded with sugar.
Ultra-processed foods refer to packaged, super-palatable foods like candy, fast food and sugar-sweetened beverages. They’re in the news because studies link consuming high amounts with increased cancer risk.
AICR advises eating a diet rich in vegetables, fruits, beans and whole grains, while cutting back on fast foods and highly processed foods that are high in sugars, starches and fats.
Processed vs. Ultra-Processed Foods
It’s important to distinguish between “processed” and “ultra-processed” food options, because a lot of food is ‘‘processed” before it’s sold and it’s not a bad word. Processes such as fermentation and canning can improve a food’s nutritional value and extend its shelf life. Even some ultra-processed foods, like sweetened yogurt, may contain sugar, but they also contain valuable nutrients such as protein and calcium. Not all processed food is harmful.
The foods that we should cut back on are those that provide low nutritional value or those that contain ingredients that are harmful to health when eaten in excess. This category includes things like sugar-sweetened beverages, candy and flavored chips.
To help highlight the difference between foods, scientists and the World Health Organization use the NOVA classification system to place foods into four categories based on how processed they are.
NOVA Food Classification System
Group 1: Unprocessed or minimally processed foods: fruits, vegetables, nuts, whole grains, fish, poultry, etc.
Group 2: Processed culinary ingredients: oil, sugar and salt used to improve flavor of group 1 foods.
Group 3: Processed foods: group 1 foods after group 2 foods have been added, such as salted nuts or canned beans and fish.
Group 4: Ultra-processed foods: foods that go through industrial processing and contain added salt, sugar, additives, etc. Examples are candy, pastries, fast food and salty snacks.
Health organizations recommend choosing more unprocessed or minimally processed foods and less of the UPF foods in group four. Yet, Americans currently get about 57 percent of calories from UPF, and that’s too high. The US Dietary Guidelines don’t address exactly how much UPF is fine to eat, but they do advise reducing added sugar, trans fats and sodium in the diet.
Study Links UPF with Cancer
A recent study on UPF was partially funded by the World Cancer Research Fund, which is AICR’s partner organization. The study found that each 10 percent point increase in consumption of UPF is linked with an increased incidence of overall cancer, especially breast and ovarian cancers.
Chronically consuming UPF may lead to overweight or obesity, which raises the risk of certain cancers. Studies also link certain additives, preservatives and contaminants in UPF with increased cancer risk. Plus, a high consumption of UPF often comes along with low intake of foods that reduce cancer risk, such as vegetables, fruits and whole grains.
Replacing 10 percent of ultra-processed foods with the same amount of minimally processed foods is associated with reduced risks of:
- Overall cancer
- Head and neck cancers
- Esophageal squamous cell carcinoma
- Colorectal cancer
- Hepatocellular carcinoma
- Post-menopausal breast cancer
Another study, which was a systematic review and meta-analysis of UPF and cancer found that a higher intake of UPF increased the risk of overall cancer, as well as colorectal, breast and pancreatic cancers.
The Bottom Line
Over the past 10 years, 38 studies have been conducted to measure the effectiveness of the AICR Cancer Prevention Recommendations and found they are effective at reducing cancer risk—with reductions of up to 60 percent for some cancers.
The Recommendations have always included recommendations to eat more vegetables, legumes and whole grains (NOVA group 1, 2 and 3 foods) while reducing ultra-processed foods with lots of sugar and starch (NOVA group 4 foods). It’s solid advice that you can rely on.
