The number of under-50s with bowel cancer in England is growing at one of the fastest rates in the world, a major study warns.

While cases of early onset bowel cancer, defined as those aged 25 to 49, is increasing globally, England's rate of the disease is growing by an average of 3.6 per cent each year – one of the fastest rises.

Experts believe poor diet, more ultra-processed foods, obesity and a lack of exercise could be responsible for the alarming trend.

The study found bowel cancer rates in young people rose in 27 out of the 50 countries studied in the decade to 2017.

Researchers from the American Cancer Society, who led the research, said the rise in early onset cancers is no longer limited to high-income Western countries but is now a 'global phenomenon'.

The rise was seen in 14, primarily high-income, Western countries including the US, Australia, Canada, France, Germany, Ireland, Norway and Scotland.

The steepest inclines in early bowel cancer incidence were found in Chile (4 per cent annual rise on average), New Zealand (4 per cent), Puerto Rico (3.8 per cent) and England (3.6 per cent).

In contrast the US only recorded an increase of 2.1 per cent — putting it 16th, behind Canada 2.8 per cent increase and Australia 3 per cent. 

While Iceland recorded a rise of 7 per cent, the highest in the study, the data behind this calculation was considered less reliable than the other countries with high increases. 

Young women were found to have faster increases in early bowel cancer rates than men if they lived in England, Norway, Australia, Turkey, Costa Rica and Scotland.

By contrast, bowel cancer rates tended to remain stable or fall in older adults in many countries, including England, partly due to the effectiveness of cancer screening programmes.

The research also recorded the actual incidence rates of bowel cancer across the countries surveyed.

Australia had the highest rate at 16.5 cases per 100,000 young people each year.

This was followed by US territory of Puerto Rico at 15.2 cases per 100,000 young people per annum and New Zealand at 14.8 cases per 100,000 people.

England came 17th in this ranking with 11.4 cases per 100,000 people per year, with other British nations in similar positions. Northern Ireland came 16th, Wales 18th and Scotland 19th. 

Dr Hyuna Sung, senior principal scientist at the American Cancer Society, said: 'The global scope of this concerning trend highlights the need for innovative tools to prevent and control cancers linked to dietary habits, physical inactivity, and excess body weight.

'Raising awareness of the trend and the distinct symptoms of early-onset colorectal cancer (eg rectal bleeding, abdominal pain, altered bowel habits, and unexplained weight loss) among young people and primary care providers can help reduce delays in diagnosis and decrease mortality.'

Experts say the exact reasons behind the disturbing, and now increasingly global, rise in colon cancer cases are still unknown.

The authors of the new study highlighted rates of bowel cancer in a number of countries surveyed increased in line with economic prosperity.

They theorised this could represent a shift away from traditional diets and increased consumption of meat and ultra-processed food, which has likely contributed to the rise.

However, they added contributing factors are likely to differ given the diversity across the globe in diets and other health metrics like obesity prevalence, which is also been linked to cancer risk. 

Cancer Research UK stressed bowel cancer rates in younger adults are still low, with only around one in 20 bowel cancers in the UK diagnosed in people aged under 50.

However, chief executive Michelle Mitchell, said this flagship study has for the first time revealed that rates are rising more sharply in England than in many other countries around the world.

She said: 'A cancer diagnosis at any age has a huge impact on patients and their families - so while it's important to note that rates in younger adults are still very low compared to people over 50, we need to understand what's causing this trend in younger people.'

Data provided by the charity up to 2019 suggests bowel cancer has seen a 52 per cent increase in incidence rates for adults aged 25 to 49 since the early 1990s.

There are around 2,600 new bowel cancer cases in people aged 25-49 in the UK every year and around 44,100 new cases among all ages.

It comes a day after US research suggested ultra-processed foods are causing chronic inflammation in the gut, which can lead to the disease.

They suggested switching foods such as cured meats, mass-produced bread and ice cream in favour of healthier alternative such as oily fish, fruit and vegetables is 'vital' to staving off the disease.

Commenting on the new findings published in Lancet Oncology, Dr Sarah Bailey, Associate Professor of health and community sciences at University of Exeter Medical School, said more research was vital to understand the trend.

'The reasons for the trend are not fully understood, but it is clear that we need to be searching for the underlying causes.

'As rates in younger adults increase, we will need to explore how we can expand our strategies to capture cases early in this group too.'

Dr David Robert Grimes, an expert in biostatistics at Trinity College in Dublin said comparing international cancer data is difficult given variation in data quality, but the findings did indicate a global increase. 

However, he urged caution about the possible reasons for the trend: 'This study cannot tell us why this might be, nor why this isn't consistent for all countries.

'It is accordingly crucial that we do not over interpret such findings. It could mean, for instance, that screening and improved detection are allowing us to catch cancers earlier.'

Multiple heartbreaking stories of young people in the prime of their lives being diagnosed with bowel cancer have emerged in recent years. 

Perhaps the most recognisable victim of the trend is Deborah James — known as 'bowel babe' — who was diagnosed at just 35 and raised millions for charity in her final days in 2022. 

Another example of a fit and healthy women being hit by the disease was Zu Rafalat, of Finsbury Park, London, who died in 2020 aged 39.

The super-fit globetrotter initially thought she had caught a stomach bug in Central America where she went on holiday in December 2018. 

It later turned out to be stage four bowel cancer which had spread to other organs.   

Another, young British women hit by the disease in her prime was  Ellie Wilcock who after experiencing a sudden pain in her abdomen, assumed that a urinary tract infection was to blame.

Ellie, now 27, from Peterborough, who enjoyed playing sports like tennis and hiking before her diagnosis, was eventually diagnosed with stage four bowel cancer – the most serious kind of the disease.

The trend isn't limited to women. Actor Chadwick Boseman, of Black Panther fame, was killed by colon cancer at just 43.