Thousands of middle-aged people in Britain are dying prematurely every year as a result of ultra-processed foods, a study has suggested.
Researchers analysed the diets of eight countries then estimated the number of deaths linked to an over-reliance on foods such as ready meals, confectionery, fizzy drinks and processed meat.
The study, published in the American Journal of Preventive Medicine, said that about 18,000 deaths in people aged 30 to 69 could be prevented each year in Britain if people ate less ultra-processed foods (UPFs).
The term refers to mass-produced foods with multiple ingredients and additives that could not be created in a home kitchen. UPFs make up more than half of the typical British diet.
Diets high in UPF have been linked to an increased risk of 32 different diseases, including diabetes, cancer, heart disease, obesity and depression.
The study looked at data on UPF consumption in Britain, Brazil, Australia, Canada, Mexico, Colombia, Chile and the United States. Britain was second only to America for dependence on UPF, which accounted for 54 per cent of average daily calorie intake. The figure for the US was 55 per cent.
The study said that every 10 per cent increase in the proportion of daily calories from UPF increased the risk of death from all biological causes, including cancer and heart disease, by 3 per cent.
Researchers calculated that 14 per cent of premature deaths, defined as deaths in adults aged under 70, could be attributed to UPF in the US and Britain. This equated to 17,781 deaths in Britain in 2018–2019, the latest year for which data was available.
In countries with lower UPF intake, such as Colombia, only 4 per cent of premature deaths were linked to UPF.
The study called for governments to issue guidelines encouraging people to cut down on UPFs and to “create healthy environments using regulatory and fiscal policies”.
Eduardo Nilson, of the Oswaldo Cruz Foundation in Brazil and lead author of the study, said that UPFs harmed health “because of the changes in the foods during industrial processing and the use of artificial ingredients, including colourants, artificial flavours and sweeteners, emulsifiers, and many other additives and processing aids”.
He added: “Policies that disincentivise the consumption of UPFs are urgently needed globally, promoting traditional dietary patterns based on local fresh and minimally processed foods.”
The study was based on observational data and could not prove a causal link. It was unclear whether UPFs were linked to death because the act of processing was in itself harmful or if the high salt, fat and sugar contents were primarily to blame.
Scientists have pointed out that people who consume lots of UPF are also more likely to have other unhealthy habits, such as smoking or not exercising, which can lead to death.
Stephen Burgess, a statistician in the Medical Research Council biostatistics unit at the University of Cambridge, said: “This type of research cannot prove that consumption of ultra-processed foods is harmful but it does provide evidence linking consumption with poorer health outcomes.”
He said it was possible that the causal factor could instead have been physical activity, but added: “When we see these associations replicated across many countries and cultures, it raises suspicion that ultra-processed foods may be more than a bystander.”
Nerys Astbury, an associate professor in diet and obesity at the University of Oxford, said: “It’s been established for some time … that consuming diets higher in energy, fat and sugar can have detrimental effects on health, including premature mortality.
“This study adds to the body of evidence on the association between UPF and ill health and disease. However, many UPF tend to be high in these nutrients and studies to date have been unable to determine with certainty whether the effects of UPF are independent of the already established effects of diets high in foods which are energy dense and contain large amounts of fat and sugar.”
Campaigners are calling for tougher regulations to restrict the advertising of UPFs and national guidelines warning of their harmful effects.
The foods are subjected to a series of sophisticated industrial processes, including splitting whole foods into oils, fats and sugar, then recombining them.
What counts as an ultra-processed food?
The term “ultra-processed foods” was devised by Brazilian scientists in 2010. It refers to mass-produced foods with multiple ingredients and additives, often loosely defined as the sort of foods your grandmother would not recognise or which could not be created in a home kitchen. These include:
• Mass-produced sliced bread
• Low-fat or sweetened yoghurts
• Breakfast cereals such as Coco Pops
• Doughnuts and biscuits
• Most protein and cereal bars
• Chicken nuggets and processed meat products
• Instant soups and noodles
• Fizzy drinks, including diet versions
• Margarines and spreads