Total ultra-processed food intake not linked to colorectal cancer in large US cohort study
Overall ultra-processed food (UPF) consumption was not associated with increased colorectal cancer (CRC) incidence in a cohort of more than 400 000 US adults, according to a study published on 15 October by Erikka Loftfield of the National Cancer Institute, US, and colleagues in the open access journal PLOS Medicine.
Ultra-processed foods account for more than half of energy intake among US adults and have attracted growing attention due to potential links to chronic diseases, including colorectal cancer. However, UPFs represent a wide range of foods. Some, like whole grain and dairy products, are associated with a lower risk of CRC while others, like processed meats, are associated with a higher risk.
To better understand these relationships, researchers analysed data from 461 682 adults aged 50 to 71 years enrolled in the NIH-AARP Diet and Health Study between 1995 and 1996. Participants recorded their eating habits using a food frequency questionnaire that researchers used to estimate UPF intake. Participants were then followed until 2018, a median of 18.8 years.
The study found no association between overall UPF intake and CRC incidence. However, findings differed by type of food. Higher intake of whole grains, fibre, dairy products, and calcium derived from UPF sources was associated with lower CRC incidence, whereas meat from UPF sources was associated with higher incidence. Researchers also found that replacing 10% of gram weight from UPF intake with minimally processed foods was associated with a 2% lower CRC incidence.
The researchers caution against generalising these findings to younger, more diverse populations. The study cohort included primarily older, white Americans and only measured UPF intake once at baseline. As a result, the findings cannot account for changing eating habits or the increasing availability in UPFs, potentially leading to an underestimation of actual UPF intake.
The study suggests that UPFs should not be treated as a monolith and reinforce current dietary guidance emphasising whole grains, fibre, dairy, and calcium while limiting processed meat intake to reduce the risk of CRC.
Loftfield adds, “In this large population of older US adults, we did not observe an association between total ultra-processed food (UPF) intake and colorectal cancer incidence; however, when we looked at food groups, like whole grains, dairy, and meat, by UPF or non-UPF source, we found that associations were in line with current dietary guidance for colorectal cancer prevention such that higher whole grain and dairy but lower meat intakes were associated with lower colorectal cancer incidence.”
Provided by PLOS
