Study associates ultra-processed foods with 25 types of cancer – 03/17/2023 – Health

Research has shown an association between consumption of ultra-processed foods and a higher risk of developing cancer in 25 different parts of the body.

The study was carried out by Nupens (Nucleus for Epidemiological Research in Nutrition and Health) at USP and published on the 6th in the scientific journal The Lancet Planetary Health.

According to the study, a diet composed of processed or ultra-processed foods was associated with a higher risk of developing cancer of all types and the most specific: head and neck, esophageal, colorectal, liver and postmenopausal breast cancer.

However, replacing 10% of the daily consumption of ultra-processed or processed foods with the same amount of fresh and unprocessed products (such as fruits and vegetables) was associated with a reduction in the risk of developing cancer.

The Nova classification groups foods according to the level of processing: in natura, minimally processed, culinary ingredients, processed and ultra-processed, with the latter being those most associated with health risks.

The research, called Epic, followed for a decade (from March 1991 to July 2001) 521,324 individuals in 23 centers in ten European countries: Germany, Denmark, France, Greece, Italy, Netherlands, Norway, United Kingdom, Spain and Sweden .

The scientists divided the participants into four distinct groups according to the average daily consumption of each food category: in the first group, the diet was almost 77% composed of in natura foods and less than 5% of ultra-processed foods; in the second and third groups, the proportions of in natura foods fell and of ultra-processed foods increased in such a way that, in the fourth group, the proportion of in natura foods was 63% and more than a quarter (25.3%) of daily consumption was ultra-processed foods.

The four types of diet were compared to assess the risk of developing 25 types of cancer. They are: head and neck, esophagus (adenocarcinoma and squamous), stomach (two types), colon, rectum, liver, gallbladder, pancreas, lung, kidneys, bladder, glioma (medulla and brain), thyroid, multiple myeloma, leukemia, non-Hodgkin’s lymphoma, melanoma, cervical, endometrial, ovary, prostate and breast.

Of the total participants, 450,111 were included in the final analysis and 47,573 had a cancer diagnosis and were followed through 2013.

The research has the advantage over randomized clinical trials because of its long duration, says Fernanda Rauber, a Nupens researcher and one of the authors.

“Prospective population studies make it possible to assess some type of association between consumption and a higher risk of disease. On the other hand, it is more difficult, not to say impossible, to measure the association when we evaluate individuals exposed to that variable in a randomized trial with the probable outcome of cancer “, he explains.

According to Nathalie Kliemann, first author of the study and researcher at the International Agency for Research on Cancer of the WHO (World Health Organization), the results point not only to the higher risk of consumption of ultra-processed foods with the late onset of cancer, something that was already known, but how this risk can be reversed with a change in habits.

“The replacement of 10% of the daily consumption of ultra-processed or processed products, according to the classification of Nova [de 2009], for the same amount of in natura or minimally processed foods caused a reduction in risk. And this has a direct effect on the development of public health promotion policies”, he says.

Kliemann points out, however, that it is necessary to change the individual look at nutritional alternatives, as if it were simply a matter of choice, to a collective look at public health. “We can’t just blame the individual, there’s a whole system behind it”, he says.

According to the researchers, Brazil is a country that has made significant advances with regard to food policies, with the launch, in 2006, of the Food Guide for the Brazilian Population, and later, in 2009, with the New classification, but the consumption of ultra-processed products has been increasing in recent years.

“At the time of the beginning of the Epic study, the daily consumption of ultra-processed products was around 30% in some developed countries. This index reached 60% in countries like Canada and the United States. In Brazil, it is in the range of 20%, but has been growing gradually in recent years”, says Kliemann.

For Rauber, the Epic survey, despite not having included data from Brazil, can be extrapolated to different countries precisely because it concentrated participants from ten European countries with different cultures and societies.