Eating processed food significantly raises the risk of cancer, experts warned last night.

They said the disease was claiming more lives because of the popularity of ready meals, sugary cereals and fizzy drinks.

The products put middle-aged women in particular danger from breast cancer, according to a study in the British Medical Journal.

‘Ultra-processed’ food – any product involving an industrial procedure – now makes up half of our diet.

Eating processed food significantly raises the risk of cancer, experts warned. They said the disease was claiming more lives because of the popularity of ready meals and sugary cereals

Packed with chemical additives, the foods bear little resemblance to home-cooked meals. And the more of them an individual eats, the higher their risk of cancer of any type.

Experts believe this is because processed foods, which include packaged meat, pies, sweets and crisps, are higher in fat, salt and sugar.

They also have less of the vitamins and fibre that ward off disease.

The procedures used to make the food – and the chemicals and additives used to boost their flavours and shelf life – are also thought to raise the risk. The researchers said it was the first study to highlight a link between ultra-processed food and an increased overall cancer risk.

Campaigners last night said families should heed the warning and read food labels more carefully to check for levels of fat, salt and sugar.

The research was based on food diaries completed by 105,000 adults. It ranked the participants by how much ultra-processed food they consumed over two 24-hour periods. For those in the top quarter of the sample, 32 per cent of their diet came from ultra-processed food.

They were 23 per cent more likely to develop cancer of any type over the next five years than those in the bottom quarter, whose diet was only 8 per cent ultra-processed food.

Women in the top quarter were 38 per cent more likely to develop postmenopausal breast cancer. The chance of younger women getting premenopausal breast cancer increased 27 per cent, and bowel cancer risk went up 23 per cent. There was no impact on prostate cancer.

The research suggests fizzy drinks are also a danger. The products put middle-aged women in particular danger from breast cancer, according to the study (file photo)

Led by experts at the Sorbonne University in Paris, the researchers said Britons were probably even more at risk because they would consume more ultra-processed food than the French adults in the study.

A study of 19 European countries published earlier this month found 50.7 per cent of food sold in the UK is ultra-processed, compared with 46.2 per cent in Germany, 45.9 per cent in Ireland and 14.2 per cent in France. The team assessed 3,300 different food products as part of the study and classed each by the level of processing they had been subjected to.

Sugary products were the most common form of ultra-processed food, making up 26 per cent of foods in this category. Drinks made up 20 per cent and breakfast cereal 16 per cent. The researchers wrote: ‘To our knowledge, this study is the first to investigate and highlight an increase in the risk of overall – and specifically breast – cancer associated with ultra-processed food intake.

‘If confirmed in other populations and settings, these results suggest that the rapidly increasing consumption of ultra-processed foods may drive an increasing burden of cancer in the next decades.’

They found no cancer link to less processed foods – such as canned vegetables, cheeses and freshly made unpackaged bread. And people who mainly ate fresh and unprocessed foods – such as fruit, vegetables, pulses, meat and fish – had a lower cancer risk. Study leader Dr Mathilde Tourier said the poor nutritional value of ultra-processed food was probably the most important factor in cancer risk.

But she added: ‘They all have food additives, they all have compounds formed during the processing and heating of the products, and they have compounds that could come from the packaging itself.

‘Most of the compounds are probably safe, but some of these substances are of concern regarding cancer risk.’

‘Ultra-processed’ food – any product involving an industrial procedure and including crisps – now makes up half of our diet (file photo)

Tam Fry of the National Obesity Forum said last night: ‘There is no smoke without fire – we should heed the scientists’ fears and read food labels more carefully. Huge quantities of everyday processed food have excessive levels of sugar, fat and salt stuffed in them and it’s all listed on the packaging.

‘Don’t risk cancer by eating anything with, respectively, much more than 15g sugar, 5g saturated fat and 1.5g salt per 100g. That’s not rocket science.’

Carolyn Rogers of the Breast Cancer Care charity added: ‘Now we need to connect the dots and find out if any specific elements in these foods may increase the risk of developing cancer.

'We know maintaining a healthy weight, through a balanced diet and exercise, is one of the best things you can do for your health. However, lifestyle is one part of a bigger, more complex picture.’

A spokesman for the Food and Drink Federation said: ‘Processed food should not be demonised – by working closely with our partners throughout the food supply chain, we can use processing positively to ensure all sectors of society have access to safe, affordable food.

‘We believe a whole diet and lifestyle approach, which includes consideration of net calorie intake, and not just the role of individual nutrients or ingredients, is the correct way to tackle such issues.’

Dr Alison Tedstone, chief nutritionist at Public Health England, said: ‘A diet high in processed foods is often high in calories, salt, saturated fat and sugar and low in fibre – this increases the risk of some cancers, as does being overweight or obese.

‘Our reduction programmes are making healthier choices easier by reducing the calories, salt and sugar in these types of foods. We’re also helping people to choose healthier options through our Change4Life and OneYou campaigns.’