Eating lots of ultra processed food could increase your risk of suffering an unsightly scaly skin condition by over a third, French research suggests.

Experts came to this conclusion after analysing health and diet data from over 18,000 people taking part in long term study on nutrition.

Dividing the group into three tiers based on the amount of ultra-processed food (UPF) they ate per day on average, the scientists found the group which ate the most had a 36 per cent increased risk of suffering from psoriasis.

Psoriasis is a skin condition that causes flaky, scaly patches of skin to appear on the body, including the face, and about one in 50 Brits have it.

It's the latest study to suggest that eating UPFs could lead to multiple health harms — from increased risk of heart disease, some cancers and even an early grave.

UPFs are a staple of the modern British diet and is an umbrella term that covers a host of foods packed with artificial colourings, sweeteners and preservatives as well as calories and sugar.

Examples include ready meals, ice cream and even ketchup.

But British experts said the French study should be treated with caution, as like many of its kind, it doesn't prove UPFs are directly to blame.

In the research, published in the journal JAMA Dermatology, the authors theorised that eating a diet high in UPFs could make the body more prone to inflammation.

This, in turn, they said could increase the chances of developing psoriasis — which develops as a result of inflammation of the skin cells.

The analysis suggested the association between high UPF diets and psoriasis remained even when aspects like excess weight of participants and underlying conditions were accounted for.

Experts still don't fully understand why psoriasis emerges, but it is thought to be related to a dysfunction of the immune system which triggers inflammation in the body and speeds up skin growth. 

Normally skin cells are replaced every three to four weeks but for psoriasis sufferers this occurs about every three to seven days. 

The study authors admitted noted flaws in their study, such as relying on participants to self-declare they suffered from the skin condition, which could have influenced the reliability of the results. 

They concluded that the relationship between psoriasis and UPFs needed further large-scale studies.

British experts, who weren't involved in the study, warned that the results should be treated with caution.

Professor Wendy Hall, an expert in nutritional sciences at Kings College London, said it was critical to remember the study showed a relationship between psoriasis and high UPF consumption — not a cause and effect. 

She suggested it's possible that having psoriasis could lead someone to eat more UPFs in order to seek comfort, as sufferers can experience self-esteem issues.

Professor Hall highlighted another flaw in the study that's common in UPF research — it doesn't distinguish between different types of heavily processed food.

Experts have voiced concerns that the term UPF is nebulous, with both a wholemeal loaf of bread which has some health benefits, and a ready meal packed with salt, fat and sugar, meeting the criteria. 

This can make it unclear which UPFs might be causing a particular health problem.

Researchers have also highlighted that UPFs might not be directly causing health problems observed in studies.

Instead, they've suggested eating lots of UPFs could be a symptom of other issues like poverty which can reduce people's intake of fresh fruit and vegetables.

Professor Hall also said the relationship between diet and psoriasis was an 'understudied' area worthy of further research. 

The UK is the worst in Europe for eating UPFs, which make up an estimated 57 per cent of the national diet.

They are thought to be a key driver of obesity, which costs the NHS around £6.5billion a year.

Often containing colours, emulsifiers, flavours, and other additives, they typically undergo multiple industrial processes which research has found degrades the physical structure of foods, making it rapid to absorb.

This in turn raises the risk of blood sugar spikes and peaks, reducing satiety.

It has also been said to damage the microbiome — the community of 'friendly' bacteria that live inside us and which we depend for good health.