An observational study published today in The BMJ has suggested a possible association between intake of highly processed, or 'ultra-processed' foods (such as packaged snacks, confectionary, sweetened drinks and ready meals) and breast cancer.
Scientists at research institutes in France and Brazil followed 104,980 people over eight years – with participants completing three web-based dietary records every six months, during which they declared all food consumed over a 24 hour period. Food and drink were categorised into four food groups based on level of processing (from minimal processing through to ultra-processing).
Adjusting for lifestyle factors which could have impacted breast cancer risk, the scientists found that a 10% increase in the proportion of ultra-processed foods in the diet was associated with a 12% increase in risk of developing cancer of any type, and an 11% increased risk of developing breast cancer.
Emphasising the need for further research into a possible association between heavily processed foods and breast cancer risk, the researchers noted that at this stage no firm conclusions can be drawn about cause and effect.
Eluned Hughes, Head of Public Health and Information at Breast Cancer Now, said:
“While it’s interesting to see that eating ultra-processed foods might be associated with an increased risk of breast cancer, this potential link must be explored further before drawing any firm conclusions.
“It is difficult to distinguish the specific effects of ultra-processed foods – or any particular food group – from those of other diet and lifestyle factors. 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. We look forward to further research to unravel the complex relationship between nutrition and breast cancer risk.
“What we do know is that limiting the amount of processed food you eat as part of a healthy balanced diet high in fruit, vegetables and pulses – as well as being physically active – can help you maintain a healthy weight, which has been scientifically proven to reduce the risk of developing breast cancer.”