Fast-food diets are confusing people’s immune systems and leading to a rise in autoimmune diseases

Eating heavily processed foods, including burgers and chicken nuggets, is leading to a rise in autoimmune diseases around the world, according to scientists.

They believe people are suffering because their immune systems cannot tell the difference between a healthy cell and a virus-like organism invading the body.

Researchers at the Francis Crick Institute in London are studying the cause in more detail, but expect it is due to fast-food diets lacking ingredients such as fibre, which affects a person’s microbiome — the collection of micro-organisms we have in our gut that play a key role in controlling various bodily functions.

Autoimmune diseases, including inflammatory bowel disease, type 1 diabetes, rheumatoid arthritis, and multiple sclerosis, are caused by the body attacking its own tissue and organs.

About 40 years ago Western nations, including the UK, saw a rise in autoimmune cases, and this trend is now emerging in countries that never had the disease before, according to James Lee and Carola Vinuesa at the Francis Crick Institute. 

Eating heavily processed foods, including burgers and chicken nuggets, is leading to a rise in autoimmune diseases around the world, according to scientists. Stock image

Some people living in the West are now managing more than one autoimmune disease at a time, according to the researchers. 

In the Middle East and Asia, there is a rise in inflammatory bowel disease cases, places that have hardly ever seen the disease until recently.

Vinuesa and Lee are looking to pinpoint the precise cause of the various types of disease, and look for links to diet.

In the UK there are four million people with an autoimmune disease, and internationally cases are rising between 3 and 9 per cent per year. 

Previous studies have found a link between environmental factors and the rise in such conditions, including more microplastic particles entering the body. 

‘Human genetics hasn’t altered over the past few decades,’ Lee told the Observer, adding that this means ‘something must be changing in the outside world in a way that is increasing our predisposition to autoimmune disease.’ 

One trend, spotted by Vinuesa, is the increase in western-style diets being adopted in more and more countries, including in the Middle East and Asia.

‘Fast-food diets lack certain important ingredients, such as fibre, and evidence suggests this alteration affects a person’s microbiome,’ Vinuesa explained.

The microbiome is the micro-organisms found in the human gut, which plays a key role in controlling bodily functions. 

‘These changes in our microbiomes are then triggering autoimmune diseases, of which more than 100 types have now been discovered.’

This isn’t the full picture, as every body is different, according to the scientists, with different risks involved in contracting an illness, and other existing conditions, also playing a part in susceptibility to an autoimmune disease.

‘If you don’t have a certain genetic susceptibility, you won’t necessarily get an autoimmune disease, no matter how many Big Macs you eat,’ Vinuesa told the Observer, adding that there ‘is not a lot we can do to halt the spread of fast food.’

‘So instead, we are trying to understand the fundamental genetic mechanisms that underpin autoimmune diseases and make some people susceptible but others not. We want to tackle the issue at that level.’

New study groups have been set up at the Francis Crick Institute in London, to be understand the impact processed foods have on healthy cells in the body. Stock image

To understand what is underpinning these disease, the team are using techniques that can pinpoint even the smallest DNA differences in large groups of people. 

This allows them to identify common genetic patterns in those that suffer from autoimmune diseases. 

The technique involves sequencing DNA on a large scale, then searching for patterns and trends within the large data generated. 

‘When I started doing research, we knew half a dozen DNA variants involved in triggering inflammatory bowel disease,’ said Lee. ‘Now we know of more than 250.’  

Lee said new treatments were needed more urgently than ever due to the spread of the various disease around the world, as there are currently no cures available. 

‘At present, there are no cures for autoimmune diseases, which usually develop in young people – while they are trying to complete their education, get their first job and have families,’ he explained.

‘That means growing numbers of people face surgery or will have to have regular injections for the rest of their lives. It can be grim for patients and a massive strain on health services. Hence the urgent need to find new, effective treatments.’