In one of the largest studies to date on processed foods, scientists followed over 44,000 French Adults to investigate the relationship between processed foods and health.
They found that that study participants who ate the most processed foods also had the highest risk of death. They also had an elevated risk of cancer.
This however does not necessarily mean that processed foods are dangerous for you. these studies could only detect correlation rather than causation. In this article, we outline the findings and our take on the results based on the research methods.
The Link Between Processed Foods and Mortality
In an analysis looking at death rates from all causes, scientists found that study participants who ate more processed food had a significantly higher risk of death over the course of the study.
They estimated that a 10% increase in calories from processed food corresponded to a 14% increase in risk of death. Using the average calorie intake and the average proportion of calories from processed food, we estimate that this difference corresponds approximately to 60-80 more calories per day from processed foods.
This amount is approximately equal to half of a can of coke or a munchkin donut hole.
Source: Association Between Ultraprocessed Food Consumption
and Risk of Mortality Among Middle-aged Adults in France
What are Ultra Processed Foods?
There are multiple definitions of processed foods. Oftentimes strange sounding ingredients are completely natural while healthy sounding food is surprisingly unhealthy.
In order to quantify processed foods, the researchers in the study used the NOVA Food Classification system. We've listed the top categories of ultra processed foods above and provide examples of what would count as ultra processed food.
The most common type in the study was sugary foods, contributing 26% of the “ultra processed foods” calories in the study. These include sweet foods such as cookies, candy, and cakes.
The second most common category was sugary drinks. While these are not technically foods, they are a significant contributor to calorie counts in many diets. For patients in this study, 20% of processed food calories came in the form of drinks.
Finally, third on the list is starchy food. Carbs are a relatively controversial food category. Keto and Low Carb diet adherents tend to avoid carbs while those on low fat and DASH diets balance carbs with other categories of foods. Both groups however reject simple carbs as unhealthy, which are generally the carbs included in this study. These simple carbs include foods made with processed grains including white bread and packaged pastries.
Source: NOVA Food Classification
The Link Between Processed Food and Cancer
One of the biggest drivers of mortality in the study was cancer. Patients who ate the most processed food had the highest risk of cancer.
In the data above, patients were split into four categories based on how much of their diet was composed of ultra processed foods.
The findings show that all patients who ate an above average proportion of processed foods had an elevated risk of cancer. Patients in the highest category of ultraprocessed food consumption were found to have a 21% higher risk of cancer than patients in the lowest quartile.
Source: Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort