According to Touvier, people should note that a balanced and diversified diet is one of the most important public health priorities as ultra-processed foods may be associated with a higher risk of cancer.
"What people eat is an expression of their lifestyle in general and may not be causatively linked to the risk of cancer". They usually lack vitamins and minerals.
They usually contain sweeteners, emulsifiers, preservatives, colours and flavours, and may be high in fat and salt.
The research was based on food diaries completed by 105,000 adults. These included hydrogenated oils, modified starches, and protein isolates in the likes of mass-produced wrapped breads, "industrialised" confectionery, frozen and ambient ready meals, and sweetened soft drinks. "By working closely with our partners throughout the food supply chain, we can use processing positively to ensure all sectors of society have access to safe, affordable food".
Foods were grouped according to the degree of processing and cases of cancer were identified from participants' declarations - and validated by medical records and national databases.
Women in the top quarter were 38 per cent more likely to develop postmenopausal breast cancer. The researchers suggested eating more raw fruit and veg.
Their findings are based on 104,980 healthy French adults (22% men; 78% women) with an average age of 43 years who completed at least two 24-hour online dietary questionnaires, created to measure usual intake of 3,300 different food items (NutriNet-Santé cohort study). Fortunately or unfortunately, they account for up to 50% of total daily energy intake in several developed countries. A 2017 study found that they make up 50% of the Canadian diet, and they make up more than 50% of the United Kingdom diet. Drinks made up 20 per cent and breakfast cereal 16 per cent.
Chemicals in processed food could "make you obese fairly quickly, but for "big" diseases it needs to be a longer study", she added.
"To our knowledge, this study is the first to investigate and highlight an increase in the risk of overall - and specifically breast cancer associated with ultra-processed food intake", said the team led by Bernard Srour from the French Institute of Health and Medical Research (Inserm) in Paris. While a small rise in ultra-processed food intake was associated with an increased risk of cancer, there was no significant link between less processed foods - such as canned vegetables, cheese and fresh bread - and cancer. This is because there might be several factors at play - for example, people who eat more processed foods might also be less physically active or have other risk factors.
A study of 19 European countries by the the University of Sao Paulo recently found that United Kingdom families buy more ultra-processed food than any others in Europe, amounting to 50.7 per cent of the diet. It could, for instance, be linked to nutritional composition, food additives or contact with packaging materials.