Fresh studies have linked consuming buns, snacks, fizzy drinks, sugary cereals and “ready meals” to significantly higher chances of heart disease, bowel cancer and death.
One of the studies, just published in the British Medical Journal (BMJ), suggests men particularly who eat high amounts of “ultra-processed” food have a much higher chance of developing bowel – or colorectal – cancer.
Past studies have linked ultra-processed food to higher risks of obesity, high blood pressure, cholesterol, and some cancers, but few have looked at its connection with bowel cancer.
The first study looked at the dietary health of 46,341 men and 159,907 women in the US, who responded to detailed questionnaires every four years, over a period of nearly three decades.
Medical and other lifestyle factors were taken into account.
It found that men who consumed most ultra-processed food – the highest fifth – had a 29 per cent higher risk of developing colorectal cancer, compared to those who ate the least ultra-processed food, the lowest fifth.
The results “remained significant” after they were adjusted to take account of respondents’ body mass index and dietary quality, the study found.
There was no link proven between consuming ultra-processed food and the risk of colorectal cancer in women, the authors said.
However, there was an “increased” risk of colorectal cancer associated with high consumption of meat/poultry/seafood based ready-to-eat products and sugar sweetened drinks among men and eating ready-to-eat or ready-to-heat meals among women.
Ultra-processed foods often contain high levels of added sugar, fat, salt but lack vitamins and fibre.
In a second study, also published in the BMJ, researchers analysed the dietary health of 22,895 Italian adults (average age 55 years), almost half of whom were men, over a period of 14 years.
The research took account of underlying medical conditions.
It showed those with the least healthy diet had a 32 per higher risk of death from cardiovascular disease and a 19 per cent higher risk of death from any cause compared with those with the healthiest diet.
“A significant proportion of the excess mortality risk associated with a poor diet was explained by a higher degree of food processing,” the BMJ report said.
“In contrast, ultra-processed food intake remained associated with mortality even after the poor nutritional quality of the diet was accounted for.”
The BMJ cautioned that both studies were “observational so can’t establish cause” and that there were limitations including “the possibility that some of the risks may be due to other unmeasured [confounding] factors.”
“Nevertheless, both studies used reliable markers of dietary quality and took account of well known risk factors, and the findings back up other research linking highly processed food with poor health,” it added.
“As such, both research teams say their findings support the public health importance of limiting certain types of ultra-processed foods for better health outcomes in the population.”
“Results from the Italian study also reinforce the opportunity to reformulate dietary guidelines worldwide, by paying more attention to the degree of processing of foods along with nutrient-based recommendations.”