Eating highly-processed foods could raise the risk of suffering a heart attack or stroke.
People who eat a lot of ‘ultra-processed’ foods, including some ready meals, sugary cereals and fizzy drinks, have been found more likely to suffer from cardiovascular disease.
Consuming more than four servings a day could raise the risk of an early death by almost two-thirds.
Ultra-processed foods are usually sold ‘ready to eat’ and could not be made in a normal kitchen, as they are packed with industrial substances like preservatives and sweeteners. They make up half of all food bought in the UK.
A French study found every 10 per cent increase in the proportion of ultra-processed food within someone’s diet raised their risk of cardiovascular problems, like a heart attack or stroke, by 12 per cent.
Separate Spanish research shows people eating more than four daily servings of ultra-processed food had a 62 per cent higher chance of dying.
This was the increased risk over the next 10 years on average, compared to eating less than two servings a day.
Experts believe ultra-processed foods may make people less full and more hungry, raising their risk of obesity, which is linked to heart problems and premature death.
Industrial ready meals tend to be high in salt and saturated fat, but there is also growing evidence some of the chemicals they contain could be harmful for the body and harden arteries.
The findings have prompted calls for governments to consider more taxes on processed foods to help people cut down.
In a commentary on the studies, published in the BMJ, researchers at Deakin University in Australia wrote: ‘These findings add to growing evidence of an association between ultra-processed food and adverse health outcomes that has important implications for dietary advice and food policies.
‘The dietary advice is relatively straightforward – eat less ultra-processed food and more unprocessed or minimally processed food.’
Ultra-processed foods, which contain few whole foods and bear little resemblance to home-cooked meals, have previously been linked to high blood pressure, depression and cancer.
There had been no investigation into cardiovascular disease, which causes a third of deaths worldwide – around half of these in Europe linked to an unhealthy diet.
The French study, led by the French National Institute for Health and Medical Research and the University of Paris, looked at 105,519 adults who filled out an average of five questionnaires on their weekday and weekend diets, taking in 3,300 separate items of food.
When these people were tracked for up to a decade, every 10 per cent rise in the proportion of ultra-processed food they ate was linked to a 12 per cent increased risk of cardiovascular disease, a 13 per cent increased risk of coronary heart disease and an 11 per cent higher risk of problems with blood supply to the brain.
Salty snacks, fizzy drinks and sugary foods were most linked to cardiovascular disease.
The Spanish study, led by the University of Navarra, looked at almost 20,000 people whose ultra-processed foods of choice mainly included processed meats, sugary drinks and dairy products.
For every additional serving of these foods they admitted eating in questionnaires, people’s risk of dying was found to rise by 18 per cent, with cancer the main cause of death.
Besides their lack of nutrients, processed foods and their packaging contain certain chemicals believed to have an effect on health.
But some experts say it is hard to avoid processed foods and not all carry the same risk.
However the Spanish study concludes that ‘targeting products, taxation, and marketing restrictions on ultra-processed products, and promotion of fresh or minimally processed foods, should be considered part of important health policy to improve global public health’.
Dr Gunter Kuhnle, associate professor in nutrition and health at the University of Reading, who was not involved in either study, said: ‘These studies are important, as they show that there is an association between the consumption of ‘ultra-processed’ foods and health which warrants further investigation.’
Victoria Taylor, senior dietitian at the British Heart Foundation, said: ‘It’s important to remember that observational studies like these can only show an association. They cannot tell us what is behind this.
‘The classification of ultra-processed foods used by the researchers is very broad and so there could be a number of reasons why these foods are being linked to increased risk to our health, for example nutritional content, additives in food or other factors in a person’s life.’