Five reasons bowel cancer is becoming more common in under 30’s

Bowel cancer is now the third most common type of cancer in Britain– and experts are concerned about a mysterious rise of cases in younger people. 

Around 100 younger people a day – 35,000 a year – are now being diagnosed with cancers more commonly seen in older people, such a bowel, breast and stomach.

Scientists are scrambling to pinpoint the cause of the mystery early onset cancer ‘epidemic‘, medically defined as the disease striking adults under-50.

This includes cases bowel cancer, a disease which strikes almost 43,000 Brits each year, killing near 17,000 per annum. 

Here, Dr Haney Youssef, bowel cancer expert and colorectal surgeon at The Harborne Hospital, part of HCA Healthcare UK, in Birmingham explains some of the reasons why the disease might be becoming more common in the under 50’s. 

Dietary changes and processed foods

Despite years of research, researchers remain baffled as to why there is an increase in younger cases of bowel cancer. 

But a diet of junk food and processed meat like burgers, bacon and fried chicken is thought to one culprit.

‘The modern diet, particularly in Western countries, has seen a significant increase in the consumption of processed and fast foods,’ Dr Youssef told MailOnline. 

He added: ‘These foods are often high in unhealthy fats, sugars, and additives, while being low in fibre. 

‘A diet low in fibre and high in processed foods can contribute to the development of bowel cancer.’

Younger generations may be relying more on convenient and often unhealthy food options which lack fibre, and it could be putting them more at risk, Dr Youssef explains. 

Fibre in our diet helps us to poo more often, which means harmful chemicals spend less time in the bowel, according to Cancer Research UK.

In contrast, processed foods are linked to range of dietary harms.

Processed meats like sausages, bacon, salami, chorizo, ham, and hot dogs, are one of the foods most widely known to increase cancer risk. 

These meats are any animal flesh that has been treated to increase its shelf life or taste better. This is often done by adding chemical preservatives such as nitrates.

The meat could also be processed through curing, smoking or salting. 

When eaten, nitrates can undergo a reaction that turns them into a substance called N-nitroso chemicals (NOCs).

These can damage the cells that line the bowel, the organ that processes food, which, in turn, can lead to the development of cancer, Cancer Research UK (CRUK) says. 

Tell-tale symptoms of bowel cancer include bleeding from your bottom, bloating, losing weight without trying, tummy pain and changes in poo, such as having softer poo, diarrhoea or constipation that is not usual for you. 

Sedentary lifestyles

Spending too much time sat at a desk or slouched on the sofa watching TV, is thought to increase your cancer risk. 

In fact, the more active you are the lower your risk of bowel cancer, according to CRUK.

‘With the rise of digital technology and changes in work and leisure activities, sedentary lifestyles have become more common,’ Dr Youssef said. 

He added: ‘Many young people spend long hours sitting, whether at a desk, in front of a computer, or using mobile devices.

‘Lack of physical activity is a known risk factor for bowel cancer, as regular exercise helps maintain a healthy digestive system and overall well-being.’

There are several reasons why keeping moving helps reduce your risk. 

Firstly, being active helps you to maintain a healthy weight which in turn helps your immune system to work at its best. 

This means the body can be better at spotting, and dealing with, cells which could go on to become cancer, CRUK says. 

Like eating fibre, exercise also helps to move food through our bowel faster, meaning anything harmful we eat spend less time in the bowel, the charity explains. 

Obesity

It’s not just eating too much junk food and not exercising enough that puts you at an increased risk, but one of the consequences, putting on too much weight. 

Obesity is the second biggest cause of cancer in the UK, according to CRUK. 

‘Obesity rates have been climbing globally, and younger age groups are not immune to this trend, Dr Youssef said.

He added: ‘Excess body fat can lead to inflammation and changes in hormone levels, which may promote cancer development. 

‘The rising prevalence of obesity in younger individuals is a contributing factor to the increased incidence of bowel cancer in this demographic.’

CRUK says that being too fat causes the level of growth hormones in the body to rise, which then causes cells to divide more often. 

Each of these additional divisions represents another potential chance for cancer cells to appear, increasing the odds of getting the disease. 

Another factor increasing risk is that immune cells are attracted to areas of the body where there are lots of fat cells. 

This can then cause an inflammation spike in these areas which causes cells to divide quicker, again increasing the risk of cancer forming.

Genetic factors

But it’s not all diet and exercise, genetics can also be putting you at a higher risk of the disease. 

‘Research has not unveiled a conclusive a connection between genetics and the increase in diagnosis – however, having a first degree relative under 50 who has had bowel cancer could suggest a higher risk for younger people,’ Dr Youssef said. 

But there are also some rare inherited conditions associated with an increased risk of bowel cancer. 

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He added: ‘While most cases of bowel cancer are sporadic, a portion of younger patients may have a genetic predisposition to the disease. 

‘Conditions such as Lynch syndrome and familial adenomatous polyposis (FAP) significantly increase the risk of developing bowel cancer at a young age – however, this only accounts for 5 per cent of all bowel cancer cases.’

Delayed diagnosis and ongoing misdiagnosis

Non-biological factors could also be playing a part in a rise in bowel cancer diagnoses. 

Increased awareness of the disease thanks to the likes of Dame Deborah James, who died from bowel cancer aged 40 in 2022, and improved diagnostic techniques, are thought to have played a role in increasing the number of young people getting diagnosed. 

Logically, the more young people know the symptoms of bowel cancer the more likely they to getting checked out as a result. 

‘Younger people are more aware of the importance of getting medical advice for symptoms such as ongoing bowel habit changes and rectal bleeding,’ Dr Youssef said.

‘As a result, this could be having a knock-on effect of the number of younger people getting diagnosed.’

While this increased awareness is a positive Dr Youssef added that there still too many cases where cancer patients face delays or problems getting a diagnosis. 

Experts estimate 40,000 cancers went undiagnosed during the first year of pandemic alone.  

Figures released last month showed NHS England met just one of its three cancer diagnosis targets. 

Of the 254,594 urgent cancer referrals made by GPs in March, 77.3 per cent were diagnosed or had the disease ruled out within 28 days. The target is 75 per cent.

‘Symptoms such as abdominal pain, changes in bowel habits, and rectal bleeding can be attributed to less serious conditions like irritable bowel syndrome (IBS) or haemorrhoids,’ Dr Youssef said.

‘For a small minority, this delay in accurate diagnosis allows the cancer to progress to more advanced stages before it is detected.’

It’s for this reason that Dr Youssef believes bowel cancer awareness is important amongst all age groups.

‘By addressing the controllable factors, such as dietary habits, promoting physical activity, and managing obesity, individuals can help reduce their risk of bowel cancer,’ he added.