Processed foods linked to a higher risk of cancer - new study

According to a new study, increased consumption of ultra-processed foods may be linked to a higher risk of developing cancer. 

Imperial's School of Public Health in London published the most comprehensive research about the link between ultra-processed foods and the higher risk of developing cancers and cancer-related deaths.

Study on 200,000 participants

The researchers used UK Biobank records and collected information on the diets of 200,000 middle-aged UK adults.

Ultra-processed foods are heavily processed foods during their production. These items include many popular packaged foods like breakfast cereal, supermarket bread, ready meals and fizzy drinks. These products are popular among consumers because they are cheap and convenient. Brands also often falsely advertise them as healthy. 

Processed foods dangerous for health

Processed packaged foods contain a lot of salt, sugar, fat and artificial additives. They negatively impact our health and are associated with obesity, type 2 diabetes, high blood pressure and heart disease.

Researchers monitored the health of 200 000 participants during a 10-year period. They looked at the overall risk of developing cancer and the specific risk of developing 34 types of cancer. They also looked at the risk of people dying from cancer.

Processed foods linked to higher risk of cancer

The latest study results show that eating more ultra-processed packaged foods was associated with a higher risk of cancer, specifically ovarian and brain cancers. Consumption of ultra-processed foods was also associated with an increased risk of dying from cancer, most notably ovarian and breast cancers.

For every 10 per cent increase in highly-processed food in a person's diet, the risk of cancer overall increased by 2 per cent, and for ovarian cancer increased by 19 per cent.

Each 10 per cent increase in ultra-processed food consumption was also linked with increased mortality for cancer overall by 6 per cent, alongside a 16 per cent increase for breast cancer and a 30 per cent increase for ovarian cancer.

These links remained after adjusting for various socio-economic, behavioural and dietary factors like body mass index (BMI), smoking status and physical activity.

Consumption of processed foods in the UK the highest in Europe

The consumption of ultra-processed foods in the UK is the highest in Europe for adults and children. This is associated with a greater weight gain in UK children and a higher risk of developing obesity and type 2 diabetes in adults.

Dr Eszter Vamos, the lead author for the study from Imperial College London's School of Public Health, commented: "This study adds to the growing evidence that ultra-processed foods are likely to negatively impact our health including our risk for cancer. Given the high levels of consumption in UK adults and children, this has important implications for future health outcomes.

"Although our study cannot prove causation, other available evidence shows that reducing ultra-processed foods in our diet could provide important health benefits. Further research is needed to confirm these findings and understand the best public health strategies to reduce the widespread presence and harms of ultra-processed foods in our diet."

"Our bodies may not react the same way to these ultra-processed ingredients and additives as they do to fresh and nutritious minimally processed foods."

Dr Kiara Chang, the first author of the study from Imperial College London's School of Public Health, said: "The average person in the UK consumes more than half of their daily energy intake from ultra-processed foods. This is exceptionally high and concerning as ultra-processed foods are produced with industrially derived ingredients and often use food additives to adjust colour, flavour, consistency, texture, or extend shelf life.

"Our bodies may not react the same way to these ultra-processed ingredients and additives as they do to fresh and nutritious minimally processed foods. However, ultra-processed foods are everywhere and highly marketed with cheap price and attractive packaging to promote consumption. This shows our food environment needs urgent reform to protect the population from ultra-processed foods."

WHO and UN recommend to reduce ultra-processed foods 

Countries around the world (France, Canada, Brazil) have been updating their national dietary guidelines with recommendations to limit ultra-processed food consumption, while in the UK there are currently no measures to tackle this problem. 

The United Nations' Food and Agriculture Organisation and The World Health Organisation (WHO) have previously recommended people to significantly reduce ultra-processed foods as part of a healthy, sustainable diet.

Dr Chang said: "We need clear front of pack warning labels for ultra-processed foods to aid consumer choices, and our sugar tax should be extended to cover ultra-processed fizzy drinks, fruit-based and milk-based drinks, as well as other ultra-processed products.

"Lower income households are particularly vulnerable to these cheap and unhealthy ultra-processed foods. Minimally processed and freshly prepared meals should be subsidised to ensure everyone has access to healthy, nutritious and affordable options."

The researchers note that their study is observational, and more work is needed in this area to establish a causal link between ultra-processed foods and cancer.