A large study suggests that increasing consumption of ultra-processed foods, such as sodas and sugary drinks, instant noodles, or packaged sandwiches / snacks, may be linked to a commensurate increase in cancer risk. However, experts caution that the finding came from an observational study and therefore more research needs to be done to confirm these results.
Observational studies are not designed to demonstrate cause and effect, but they can provide information on the links between variables such as diet and disease.
In this case, the researchers analyzed the diet and health of 105,000 middle-aged people in the NutriNet-Santé cohort study. The participants gave information on their typical consumption of thousands of different foods (3,300 specifically). They found that for every 10% increase in the proportion of ultra-processed foods consumed, there was a 12% increased risk of cancer.
Further analysis revealed an 11% increased risk of breast cancer, but no significant link in the case of prostate cancer or colorectal cancer.
Implications for health and well-being
The latest estimates of global numbers suggest that there were 14.1 million new cancer cases in 2012, and that this number is expected to rise to 24 million by 2035.
In their new study, the researchers cite scientific evidence suggesting that many countries are moving toward increased consumption of “ultra-processed foods,” or foods that have undergone various “physical, biological, and / or chemical processes.” Therefore, the health consequences of this trend should be studied, because ultra-processed foods have a series of characteristics that could cause diseases. For starters, they’re higher in added sugar and salt, as well as total fat and saturated fat, and they’re lower in fiber and vitamins.
Additionally, these foods contain additives that, although approved for food use, remain controversial, as some animal and cell studies have suggested that they may cause cancer.
It is a relatively new field of research
The solid evidence is “still very scarce,” the authors write. This study “is the first to investigate and highlight an increased risk of cancer in general and, specifically, of breast cancer associated with the intake of ultra-processed foods.”
Detailed food classification
For their study, the incidence of cancer was measured over an average of 5 years. The data were taken from the information on the participants’ reports and collated with medical records and national databases.
The researchers classified the foods into four groups, according to the “scope and purpose of industrial food processing.” Ultra-processed foods are those that, according to the classification system used in the study, undergo the most industrial food processing.
Some examples of substances added during industrial processing include flavoring, coloring, wetting, emulsifying, and artificial sweetening agents.
The study did not reveal a significant relationship between cancer and the consumption of less processed foods, and a lower risk of general cancer and breast cancer with the intake of fresh and minimally processed foods.
Reference: Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort BMJ 2018; 360 doi: https://doi.org/10.1136/bmj.k322
