A combination of eating too much sugar and not enough fibre could be one reason why colon cancer cases among younger people are on the rise, scientists have said.

Experts have also said that while genetic conditions account for around 5% of bowel cancer cases, the rest “remain poorly understood”.

Poor diet is thought to be one reason why cancer rates among younger people are on the increase.

The team behind the latest research, which was presented recently at the world’s largest cancer conference, say that the aging of cells are sped up because of a bacteria produced as a result of eating too much sugar and not enough fibre.

This makes the cells more vulnerable to mutations that can lead to cancer, as well as making them less able to see off the growth of tumour cells.

The researchers detailed how they looked at genetic samples from people aged under 50, and those who were older, who all had colon cancer.

They say that a high sugar, low fibre diet consumed by younger people produces the bacteria Fusobacterium, which increases inflammation throughout the gut.

Conversely, fibre slows down the release of glucose in the blood and feeds healthy gut bacteria that help to lower inflammation.

Poor diets aged cells in the young colorectal cancer patients by up to 15 years beyond the individual’s age, a process dubbed ‘inflammaging’.

The researcher said: “These data suggest that pathogenic microbes may induce inflammation, which leads to accelerated aging in [early-onset colorectal cancer].”

The findings support other recent evidence which suggests that processed, low-fibre diets are playing havoc with the gut microbiome balance.

Around 95% of Americans are not eating enough fibre, while only around 9% of people in the UK consume the recommended 30g of fibre a day.

Over the last 20 years, there has been a 24% rise in the number of people under 50 being diagnosed with cancer in the UK, a bigger increase than any other age group.

Many experts believe modern diets could be the cause, with two in three adults overweight or obese in the UK.

Professor Charles Swanton, from Cancer Research UK, spoke recently about his concerns about rising cancer cases in younger people, saying: “Over recent decades, there has been a clear increase in cancer incidence rates in young adults in the UK.

“Evidence suggests that more adults under 50 may be getting cancer than ever before.

“Although these cases are a small proportion of the overall population and still relatively uncommon, the trend is important, and it requires further investigation.

“Increased exposure to known as well as unknown cancer risk factors, changes to lifestyles and diets over time, and rising obesity may all contribute to the uptick.”

He added: “Genetics, improvements in diagnosis and screening and the microbiome could also play a role.

“We are seeing them through our clinics and it is disturbing and we don’t have a good answer as to why this is happening.”

A study by the University of Florida is being carried out to examine the effect of energy drinks on younger colorectal cancer patients.

Get our free newsletters

Stay up to date with the latest news, research and breakthroughs.