Ultra-processed meats ‘boost risk of early death’

Eating ultra-processed meat products such as chicken nuggets and hot dogs can send you to an early grave, according to a major new study.

Researchers at Harvard University tracked the diets of more than 100,000 adults in the US for three decades, finding a link between the consumption of mass-produced foods and the risk of dying.

Diets high in ready-made processed meat and fish products appeared to be the most harmful, increasing the risk of death by 13 per cent. This category includes items such as shop-bought sausages, burgers, fish fingers, chicken nuggets and turkey twizzlers.

The study, published in the British Medical Journal, involved data from more than 114,000 middle-aged nurses and health professionals, who were tracked between 1984 and 2018.

The participants completed a detailed food questionnaire every four years to assess their diets. They were divided into four quartiles based on their consumption of ultra-processed foods — industrially produced food and drink items, often packed with additives, which make up half of the typical British daily diet.

Over the 34-year study, 48,193 of the participants died. The chance of dying was compared with their diets, with results adjusted for age and other diseases.

Of the four groups, those who ate the most ultra-processed foods overall were 4 per cent more likely to die than those who ate the least. This group ate on average seven servings of ultra-processed food a day, compared to three servings a day for the least ultra-processed group. One serving equates to a bowl of breakfast cereal, a can of fizzy drink, a rasher of bacon or a slice of bread.

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The study broke down the extra risk by the type of ultra-processed food. Meats were linked to the biggest increased risk, with the quartile of participants who ate the most ultra-processed meat products 13 per cent more likely to die. Fizzy drinks and breakfast cereals were also highlighted as significantly increasing the risk.

However other categories of ultra-processed food, including sauces such as shop-bought mayonnaise and packaged savoury snacks such as crisps, were not found to increase death risk.

The study has been published amid a fierce debate about the harms of ultra-processed foods, with some experts calling for blanket restrictions to be placed on their marketing to help tackle obesity.

Mingyang Song, an associate professor in nutrition at the Harvard TH Chan School of Public Health and the lead author of the study, said the findings support “limiting consumption of certain types of ultra-processed food for long-term health”.

However, Song stressed that not all ultra-processed food products should be universally restricted and said it was important to avoid oversimplification when writing dietary guidelines.

Other scientists have pointed out that some products which are minimally processed — such as a fresh cut of red meat — can still be unhealthy if consumed in excess. Meanwhile some ultra-processed foods — such as baked beans or sliced bread — can be staples of a healthy diet. Previous research has linked ultra-processed foods to heart disease, high blood pressure, cancer, depression and diabetes. The link is partly because these foods are often high in fat, salt and sugar, but some experts believe that the way the foods are manufactured means they are inherently harmful and damage gut health.

Duane Mellor, a dietitian and spokesman for the British Dietetic Association, said the new study “suggests that not all groups of ultra-processed foods are associated with the same health risks, with sugar and artificially sweetened drinks and processed meats being most clearly associated with risk of an early death”.

Gunter Kuhnle, a professor of nutrition at the University of Reading, said: “We know from previous studies and this one that there is plenty of evidence for limiting foods high in saturated fat, salt and sugar — which some ultra-processed foods tend to be high in.

“Public health policy should be informed by evidence, and there is very good evidence about the health effects of foods based on their composition — which is largely confirmed by this study. In contrast, there is still virtually no robust evidence for an effect of ‘ultra-processing’ specifically on health.”