Not long ago, bowel cancer was not something that people in their 30s, like myself, had to worry about. But that’s all changed.
Just about everyone my age is now aware that the deadly disease is surging in under-50s – and that doctors have no idea why.
In Britain, anyone under 50 today is about 60 per cent more likely to develop bowel cancer than under-50s were in the early 1990s. Theories have abounded, ranging from nutrient deficiencies, chemicals found in sausages and bacon, the growing number of babies born via caesarian and even traumatic events in childhood.
But so far, no one has been able to come up with a clear answer. It is why, last week, researchers at King’s College London announced a major, first-of-its-kind study, with the goal of identifying the hidden triggers of bowel cancer. The ambitious £20million study, called Prospect, will track the lifestyle habits and health of more than 250,000 people over many years. They will be asked to fill in twice-yearly surveys on how they are living their lives and whether they have developed any diseases.
Perhaps what is so strange about the rising rate of bowel cancer in young people is the fact that many who develop it are seemingly healthy and active with no underlying medical problems.
And that is also how I would describe myself.
So what exactly is my bowel cancer risk? To find out, I signed up for Prospect, and then asked the leading researchers behind the study to analyse my lifestyle and health records to identify how likely I was to develop the disease before the age of 50.
The results were both surprising and deeply worrying. Moreover, they suggest that countless other young people who believe they are safe from bowel cancer could also be equally at risk… or worse. So what are the suspected hidden triggers of early-age cancer? And what can you do to protect yourself against the disease?
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Every year about 44,000 people are diagnosed with bowel cancer in the UK. The disease, also known as colorectal cancer, kills about 17,000 over the same period.
There are some lifestyle habits that are known to increase the risk of bowel cancer. These include obesity, lack of exercise, excessive alcohol consumption and smoking.
Crucially, another recognised factor is a lack of fibre.
Studies show the nutrient, which is found in root vegetables, seeds, nuts and wholegrain bread, is important for good bowel health.
Research shows that for each additional 10g of fibre per day people consume, they reduce their risk of bowel cancer by 10 per cent. Yet studies also conclude that around 90 per cent of Britons do not get their recommended daily fibre intake of 30g.
However, experts say these known risk factors alone cannot explain the marked increase in the number of people under the age of 50 developing the disease – not least because so many were seemingly healthy and active before their diagnosis.
One such case is that of Dawson’s Creek star James Van Der Beek who died earlier this year after a two-year battle with bowel cancer at just 48 years old.
And the former teacher turned broadcaster, journalist and campaigner Dame Deborah James died in 2022 at the age of 40, after being diagnosed with bowel cancer at 35.
‘There are so many people who develop early-onset bowel cancer who don’t have any of the classic risk factors,’ says Dr Rosiered Brownson Smith, a King’s College London researcher working on the Prospect study. ‘These are often healthy, young people. Currently we can’t explain why they are getting the disease.’
The new study hopes to answer this question.
In order to do this, participants are meticulously quizzed on every aspect of their life. What they eat, where they live, what they do for work, their mental health.
And the questions – which number in the hundreds – don’t just focus on the present.
Broadcaster, journalist and campaigner Dame Deborah James died in 2022 at the age of 40, after being diagnosed with bowel cancer at 35. She became known as Bowelbabe
Participants are also asked to recount their childhood. Were they bullied? Did they move around often? Did they have any illnesses or injuries?
None of the questions are asked at random. They all relate to scientific research into the causes of early-age bowel cancer.
The bullying in childhood question, for example, relates to studies that suggest stress can damage the bowel, raising the risk of abnormal changes that become cancerous later in life.
The researchers say they are nowhere near close to saying whether any of these possible triggers is the culprit. Instead, the goal, explains Professor Sarah Berry, a nutritional science expert at King’s College London and the study leader, is to cast as wide a net as possible. No potential trigger is off the table.
‘That’s why we need a vast number of people involved,’ she says. ‘Our hope is that, with that many participants, we can begin to see a pattern emerge in the lifestyles of those who develop bowel cancer.’
Participants entering the study would not ordinarily receive feedback on their answers. This is, in large part, because much of the data is anonymised to protect the privacy of those involved.
However, the Prospect researchers agreed to analyse my answers and explain where, according to early studies, I may be increasing my risk of bowel cancer.
Before I sat down to fill out the questionnaire, I felt confident that I was at low risk of developing early-age bowel cancer.
I pride myself on having a good diet and I exercise regularly. Admittedly, I enjoy a drink and the occasional cigarette. I also have a form of spinal arthritis, for which I take medication. But, by and large, I consider myself a sensible, healthy person.
But within a few questions I encountered my first risk factor. I’m asked whether I was born via a natural birth or caesarian. As it happens, I was a caesarian baby.
‘We know there is a link between being born as a caesarian and developing bowel cancer,’ says Dr Brownson Smith. ‘The theory is that there are certain microbes picked up during a natural birth that may be crucial for good health. It’s something we are looking into.’
Another issue the study is looking at is the effect of microplastics: minuscule plastic particles that have been found in food, water and even human organs.
‘Studies show that people who eat more calcium are less likely to get bowel cancer,’ Professor Berry says. ‘Cheese is made with dairy, meaning it’s got plenty of calcium.’
The questionnaire asks whether participants store food in plastic containers or drink from plastic water bottles. I rarely do either.
But it isn’t only plastic packaging that is the problem. I chew gum every day and, apparently, this is packed with microplastics.
Then there is poor sleep. Early research suggests that patients with sleep disorders are three times more likely to develop the cancer within five years. As someone who regularly wakes in the night, this is alarming to hear.
But perhaps the most sobering moment comes when I discuss my daily eating habits with Prof Berry.
Participants are asked to fill out a food diary recording everything they consume over three days, including one day at the weekend. This is the section I expected to ace. I take my diet seriously.
Having read all the research into the benefits of fibre, I make sure to get my recommended 30g a day.
In fact, I was pleased to find out that on one of the days I ate a whopping 48g of fibre.
However, I was surprised when the researchers flagged other aspects of my diet as worrying.
Prof Berry pointed out that, on two of the three days, I had eaten processed meat: pork sausages one night, and chorizo in a stew on another.
The research linking processed meat to bowel cancer is among the strongest, and believed to be due to the nitrates it contains – a chemical preservative used to keep meat fresh for longer.
Some studies suggest that people who consume a diet rich in nitrates are as much as 25 per cent more likely to develop bowel cancer.
‘It’s fine to eat processed meat occasionally in small portions – such as using it to add flavour to a meal,’ says Prof Berry. ‘But eating it every day is not a good idea.’
It wasn’t all bad news. I usually try to avoid eating too much cheese because it contains high levels of fat. But when I tell Prof Berry I grated cheddar on to my Friday night stew, she tells me that this, in fact, could reduce my risk of bowel cancer.
‘Studies show that people who eat more calcium are less likely to get bowel cancer,’ she says. ‘Cheese is made with dairy, meaning it’s got plenty of calcium.’
But the most shocking moment was when Prof Berry took me to task on my snacking.
Most days I eat a protein bar between meals, often before I go to the gym. And while they come in unhealthy-sounding flavours, such as salted caramel, they all claim to be low in sugar and high in protein, a nutrient that helps muscle growth.
The moment Prof Berry spots the bars on my food diary, she pulls up the list of ingredients and goes through them. Protein blend. Cocoa mass. Humectant. Glycerol. Maltitol. Palm oil. Rapeseed oil. Bulking agent. Emulsifier.
These, she explains, are considered ultra-processed foods. UPFs have been increasingly linked with chronic diseases, including heart disease and diabetes.
In the case of cancer, there is research suggesting that emulsifiers in particular – added to snack bars and other ready-made meals to stop the various ingredients from separating – may damage the lining of the bowel, raising the risk of the disease.
‘All we know is that they are synthetic and contain nothing of nutritional benefit,’ says Prof Berry. ‘We don’t know yet what the impact of consuming synthetic ingredients day after day is, but it’s something people should be cautious of.’
Experts say it is important that patients do not obsess over their bowel cancer risk. In many cases, it can simply be down to bad luck. It is also possible for people to regularly consume things linked to cancer, such as alcohol, cigarettes and processed meat, and never develop the disease.
However, learning more about these risk factors has made me reassess my habits.
Of course, there are certain aspects you can’t change – not least how you were born or childhood experiences. And then some habits are harder to fix than others. I’m a bad sleeper, but no matter what I do, that doesn’t change.
But there are habits I know I can change right now: smoking, drinking, chewing gum and eating protein bars. These are all things that I could give up.
So perhaps it’s time I kicked the social cigarette and started eating a handful of walnuts when hungry instead of a chocolate chip salted caramel snack bar.
As for the Prospect study, the researchers say, if enough people sign up they could begin to find answers in the next few years.
‘We’re hoping that by 2028 we might be able to publish our first findings,’ says Dr Brownson Smith. ‘The more people we recruit, the more information we will get, and that will help us crack this question.’
To sign up for the Prospect study, visit: healthspanconnect.kcl.ac.uk/our-studies/sign-up-to-prospect-uk-here/
