Cancer from eating the wrong food?

Highly processed foods increase the risk of cancer. Consumption is particularly dangerous for women: the worse the diet, the greater the risk of ovarian cancer.

Cancer risk from highly processed foods

Almost 200,000 people from the United Kingdom took part in the prospective cohort analysis.
Between 2009 and 2012, they were interviewed several times about their diet using a web-based 24-hour recall.
The foods and drinks consumed were categorised into four groups (unprocessed to highly processed) according to the degree of food processing.
Exposure was determined by the percentage of UPFs in the total food intake in g/day.
Covariates such as age, gender, family history of cancer, household income, educational levels, smoking status, physical activity and body mass index were considered in the analysis.

Ready meals and fast food are becoming increasingly popular in our fast-paced society. The USA and the United Kingdom are leading the way with an average UPF share of more than 50% of daily calorie intake.

Is there a link between UPF and cancer risk?

In the study, subjects covered almost a quarter of their daily food intake with UPFs, ranging from about 10% to 40%. A high consumption of ultra-processed foods was associated with an increased BMI, low physical activity and low socio-economic status.

This was also noticeable in the cancer figures: During a mean follow-up period of just under 10 years, 15,921 people developed cancer, with the incidence rising as UPF consumption increased. An increase in UPF content by 10 percentage points was associated with an increased number of cancer cases overall (HR, 1.02; 95% CI, 1.01-1.04). This correlation was particularly clear for ovarian cancer (HR, 1.19; 1.08-1.30).

Compared to those who had a largely healthy diet, the participants with the highest consumption of UPF had a 7% higher overall cancer risk (95% CI, 1.02-1.14). The risk of lung cancer was 25% higher (95% CI, 1.01-1.57) and the risk of diffuse large B-cell lymphoma was 63% higher (95% CI, 1.00-2.66).

Does an unhealthy diet also increase cancer mortality?

A similar picture emerged for cancer mortality. The higher the UPF consumption, the greater the mortality risk for all types of cancer as well as for certain tumour diseases, above all ovarian cancer. Here, the difference between healthy and unhealthy eating behaviour was more than 90% (HR, 1.91; 95% CI, 1.08-3.39).

Although the study cannot prove causality, it does indicate that an unhealthy diet could be associated with a greater cancer burden. In addition to the poorer nutritional composition of UPFs (energy-dense, high in salt, sugar and fat, low in fibre) the authors also consider harmful substances produced during industrial processing to be carcinogenic. Food additives and certain packaging materials could also play a role.

Take-away for medical practice

Cancer rates are rising worldwide. It is estimated that at least 50% of all cancer cases could be prevented by lifestyle changes. The study shows that healthy eating alone could be an effective tool in the fight against cancer.

Source

Chang K et al. Ultra-processed food consumption, cancer risk and cancer mortality: a large-scale prospective analysis within the UK Biobank. EclinicalMedicine 2023;56: 101840. https://doi.org/10.1016/j.eclinm.2023.101840