Hey there,

You probably know that what we eat has a big impact on our health. But did you know one of the largest studies ever — with more than 450,000 people — confirmed that even small food swaps can lower cancer risk?

According to the study, published in The Lancet Planetary Health in March 2023, replacing even a small part of what we eat with minimally processed foods significantly reduces cancer risk.

This research, called the European Prospective Investigation into Cancer and Nutrition (EPIC), followed participants since 1991. The findings show that replacing just 10% of processed foods with minimally processed ones reduced overall cancer risk by 4%. For certain cancers, the effect was much greater:

• Esophageal cancer risk decreased by 43%

• Liver cancer risk decreased by 23%

The study also showed that cutting down on ultra-processed foods helps too, though to a smaller degree. Substituting 10% of ultra-processed foods with minimally processed ones reduced overall cancer risk by 1%, liver cancer by 27%, and esophageal cancer by 20%.

This study builds on earlier research by the same team, led by Dr. Nathalie Kliemann of the International Agency for Research on Cancer (WHO, Lyon). That earlier study, based on over 200,000 adults in the UK, found that every additional 10% of ultra-processed food in the diet was linked to a 2% higher overall risk of cancer and a 19% increase in ovarian cancer risk.

To better understand the link between food processing and cancer, researchers needed a larger cohort — which is why the EPIC study was launched. It included over 450,000 participants from 1991 to 2001, with an average age of 51 at enrollment. Within 14 years, 47,573 were diagnosed with cancer.

Foods were classified using the NOVA system, which groups them by processing level:

• NOVA 1: unprocessed or minimally processed

• NOVA 2: processed ingredients

• NOVA 3: processed foods

• NOVA 4: ultra-processed foods

Replacing just 10% of processed foods (NOVA 3) with minimally processed ones was linked to a lower overall cancer risk, especially for esophageal, liver, brain, throat, colon, and post-menopausal breast cancers.

When it comes to ultra-processed foods, the results were less clear. At the time of the study, these foods represented about 32% of daily calorie intake among participants — but today, that number could be nearly double in many European countries. Researchers explain that this may be why the data on ultra-processed foods is limited compared to processed foods.

While the conclusions confirm what many earlier studies suggested, this is the first large-scale research to clearly link processed foods with colorectal cancer and post-menopausal breast cancer.

As Dr. Kliemann told Medscape: “This study is the most extensive investigation of the links between food processing and cancer risk, and its size explains why we were able to identify specific cancer types.”

The key message is simple:

• The more fresh, minimally processed foods we eat, the lower our cancer risk.

• A diet high in processed foods increases risk — and this is no longer just theory, but now backed by the most comprehensive study so far.

Source: The Lancet Planetary Health