The little-known cancer you need to be aware of...

It’s a topic we don’t often talk about, but bowel health is essential for our overall wellbeing and any problems with the bowel – from a simple change in the frequency of your visits to the loo to more alarming symptoms such as blood in the stool – can be a sign that there’s something worth going to the GP for. Knowing what to look for and what puts you at greater risk is key, as bowel cancer diagnosis are on the rise.

Dr Deborah Lee of Dr Fox Online Pharmacy says, ‘The incidence of bowel cancer in young people aged 25 to 49 has risen between the 1990s and 2018 by 22%. Don't get too confused by this statistic, as 90% of bowel cancer still occurs in people aged over 50. But this does mean that 10% of bowel cancers are now present in younger people, sometimes in their 20s and 30s.’

Dr Lee says the cause of this rise in bowel cancer in young people has caused much consternation and no single cause has been identified – it is thought to be due to a combination of risk factors, which we’ll cover in this feature.

Dr Angela Rai, GP at The London General Practice says, ‘Bowel cancer can affect anyone of any age. …Nearly six out of ten cases (59%) are diagnosed in people aged 70 or over. However, more than 2,500 new cases are diagnosed each year in people under the age of 50. 1 in 15 men and 1 in 18 women will be diagnosed with bowel cancer during their lifetime.’

This type of cancer is treatable and curable, especially if diagnosed early. Dr Rai reassures us that nearly everyone survives bowel cancer if diagnosed at the earliest stage. ‘However, this drops significantly as the disease develops. Early diagnosis really does save lives,’ she says. Here’s what to be aware of.

Risk factors

As you’ll have noticed already, being aged over 50 is a significant risk factor, but there’s also a strong family history link with bowel cancer. ‘If you have a first-degree relative with bowel cancer under the age of 50, this triples your risk,’ says Dr Lee. ‘Anyone who thinks they may have a higher risk of bowel cancer should discuss this with their GP and they may be offered screening at a younger age.’

Screening via a FIT test is routinely sent by post to all UK adults registered with a GP, aged 54-74. ‘The first thing you can do to prevent bowel cancer is to complete your screening test,’ says Dr Lee. ‘Current figures show that around 30% of the population never sends these tests back. This is very sad, as the NHS bowel screening programme saves around 10,000 lives per year. The test is simple, painless and free.’

‘Although bowel screening is not routinely offered to younger groups, if individuals have bowel symptoms or a family history of bowel cancer, they should seek advice from their GP,’ adds Dr Rai. ‘Further tests can then be offered. Screening is a way of testing healthy people to see if they show early signs of cancer, when there is a good chance of successful treatment. Screening can also find non-cancerous growths (polyps) in the bowel that may develop into cancer in the future. Removing these polyps can reduce your risk of getting bowel cancer.’

Another risk factor is having hereditary cancer syndromes. ‘16% - 35% of early-onset colorectal (bowel) cancer (EOCRC) is due to hereditary cancer syndromes,’ says Dr Lee. ‘These include Lynch syndrome, polyposis syndromes such as familial adenomatous polyposis, MUTYH-associated polyposis, juvenile polyposis, and others. All patients with EOCRC should have genetic testing to identify these conditions.’

Likewise, long-standing inflammatory bowel disease such as Crohn’s disease or ulcerative colitis can also increase your risk. Otherwise, it’s down to lifestyle factors, which is a positive thing as it’s something you have some control over.

All about diet

Essentially, it comes down to what we eat, how we move and our chemical intake. ‘There are a number of lifestyle factors that can increase your risk of bowel cancer, such as obesity, alcohol consumption, smoking, eating too much red and processed meat and eating too little fibre,’ says Dr Rai.

‘So, it would be recommended to quit smoking if a smoker, reduce your intake of alcohol and try and have a healthy BMI. In addition, eating lots of fibre from wholegrains, pulses, vegetables and fruit helps to reduce your risks of bowel cancer.’

Dr Lee takes a closer look at these modifiable risk factors, starting with diet. ‘Unfortunately, the Western diet with its high intake of red meat and processed foods – that are typically high in fat and sugar and low in fibre – increases the risk of carcinogenesis due to insulin resistance, hyperinsulinaemia, altered bile acids and unfavourable changes in the gut microbiome. Recent research shows that ultra-processed foods make up two-thirds of the diet of UK adolescents.

‘Young people eat more red meat than older people. According to The International Research Agency for Cancer (IARC) processed meat is a type 1 carcinogen. This means eating processed meat is as dangerous for cancer risk as smoking. Red meat ‘probably’ causes cancer and is classed as a type 2a carcinogen. Even eating small amounts of red/processed meat carries an increased risk.’

Confused over what constitutes processed or red meat? Processed meats include bacon, ham, salami, sausages, corned beef and hot dogs. Red meat is beef, lamb, pork and goat.

‘Red meat contains haem, a red blood cell pigment,’ says Dr Lee. ‘It also contains nitrates and nitrites. Plus, heterocyclic polyamines are produced during cooking. All these substances are carcinogenic in the bowel. Just swapping one meat or a meat-free meal per week lowers the risk of bowel cancer by 9%.  Instead of red meat, on the other days, eat fish and chicken. Keep your red meat portion size to more than 70 g per day.’

SuperNutrio’s Registered Nutritionist Natalie Rouse also highlights calcium intake as a way to decrease the risk of bowel cancer. ‘It’s well known that calcium is a must for building strong bones, but it’s also essential for maintaining our overall health and wellbeing. A recent study by Cancer Research UK found that by consuming an extra 300mg of calcium a day, roughly the amount found in one glass of standard milk, you can significantly lower the risk of bowel cancer. 

‘Food and drinks which are rich in calcium make incorporating this vital nutrient into your diet even easier. Containing 80% more calcium than regular cow’s milk, a glass of SuperNutrio provides much more than the recommended daily intake to help prevent bowel cancer. This means that in comparison, you’d only need 140ml of SuperNutrio per day to reach the new recommended amount of calcium.’

So that’s meat and dairy covered. What about fibre? ‘Although the NHS recommendation is for a minimum of 30g of fibre per day, the average UK adult has just 18g a day,’ says Dr Lee. ‘Not having enough fibre in the diet slows the transit of food through the gut meaning partially digested food stays for longer in contact with the bowel wall. Bacteria feed off fibre in the diet, and not having enough fibre means the right bacteria are not present in sufficient numbers to confer protection. In addition, high-fat, high-sugar foods can produce harmful metabolites which cause gut inflammation.

‘Think about how to get more fibre into your diet. Choose brown bread, pasta and rice instead of the white alternatives, as these are made from fibre-rich wholegrains. Choose whole grain (unrefined) cereals such as oats, wheat or barley. Make sure you eat your 5 a day – some now say 10 a day – because fruit and veg are full of fibre. Incorporate beans, lentils, chickpeas, nuts and seeds as part of your regular diet.’

Dr Reshma Rakshit, Doctify-rated Consultant Gastroenterologist, adds that staying hydrated is vital for bowel health. ‘Try to drink 1.5-2 litres of non-caffeinated fluids per day to keep bowel movements regular. On that note, you should avoid postponing the urge to go to the toilet – over time this can lead to disordered bowel function – and avoid straining at stools; find a cause and treat it. Often this is due to constipation. I’d also recommend avoiding taking the mobile phone to the bathroom as this increases time spent straining and can lead to piles, bleeding and fissures… and very unhygienic!’

Dr Rakshit advises raising your feet on a stool to allow the knees to be higher than your hips, leaning forwards and putting your elbows on your knees, bulging out your tummy whilst straightening your spine. Avoid straining. If nothing happens, stop trying, go for a walk, try a hot drink and when the urge comes try again. This takes time and patience to develop.  

Obesity, type-2 diabetes and raised cholesterol also pose a risk in developing bowel cancer, all of which are on the rise. ‘Don’t be in denial about your weight,’ says Dr Lee. ‘Two-thirds of UK adults aged 35 and above are obese. Excess body fat appears to be a trigger for tumour development due to abnormal cell-signalling pathways, hormonal changes and the presence of insulin-like growth factors found in adipose tissue.

‘Most type-2 diabetes occurs in those aged under 40. High glucose and insulin levels raise the level of inflammation in the body, which increases the risk of bowel cancer cell production and growth. The number of people with type-2 diabetes has been steadily rising. Meanwhile, 53% of UK adults aged 16-44 have raised cholesterol and studies show that raised LDL cholesterol is also linked to increased bowel inflammation. Anything that raises inflammation increases cancer risk.

‘For the best chance to stay healthy, you should have a BMI in the normal range of 21-25. Being overweight or obese significantly increases your risk of bowel cancer. See your GP for help and advice about weight loss. The NHS can now prescribe various weight loss drugs including GLP-1 agonists such as Mounjaro, if you meet the criteria.’

Gutsy move

It’s important to move too if you’re looking for a healthier lifestyle. ‘A recent study from Bristol concluded that 80% of adults do not do enough exercise,’ says Dr Lee. ‘Lack of exercise is linked to obesity which increases the risk of bowel cancer. It is also linked to constipation which also increases bowel cancer risk. Exercise lowers chronic inflammation in the body, and lowering inflammation reduces cancer risk. It also helps stimulate the immune system, and a healthy immune system is needed to prevent cancer development.

‘Follow the NHS recommendations for exercise – adults should undertake 150 minutes (5 x 30 minutes of moderate-intensity exercise (MIT) per week. This is any exercise that makes you feel slightly sweaty and out of breath – such as brisk walking, jogging, cycling, dancing or swimming. Your body hates being sedentary. Being more active will lower your risk of cancer.’

What about your microbiome? Can good bacteria combat bowel cancer? ‘Microorganisms can cause cancer – for example, the bacterium Helicobacter Pylori and stomach cancer,’ says Dr Lee. ‘Researchers have been examining the bacteria in the bowel to see if a change in the flora could be linked to bowel cancer.

‘A recent study in the journal Nature has identified a toxin called colibactin, produced by a specific strain of the bacteria E.coli which could be a cause of bowel cancer. Colibactin causes specific DNA mutations that are more likely to be found in tumours of those with early onset bowel cancer than in those of older people.

However, many people will harbour this E.coli and never develop bowel cancer. This type of E.coli bacteria infects around 1,500 UK population per year. It is found in undercooked beef, and in leafy greens like romaine lettuce and spinach, as it can become contaminated in the fields through irrigation water or livestock. Also, in any fruits/vegetables and in unpasteurised dairy products.

Dr Lee recommends you include probiotics in your regular diet. These are healthy bacteria and yeasts found in fermented foods such as yoghurt with live cultures, kefir, kombucha sauerkraut and pickled cabbage. ‘There is no formal recommendation this will reduce your risk of bowel cancer but it may well help you to have a healthier gut,’ she says.

Vices and vitamins

Now let’s look at chemicals – alcohol and cigarettes. ‘Although young adults are less likely to drink than older adults, they are more likely to binge drink and drink at high-risk levels,’ says Dr Lee. ‘Alcohol is metabolised to acetaldehyde which is a known carcinogen. It can cause mutations in cells in the bowel wall, which then grow into a bowel tumour.

‘Don’t be under any illusions. Alcohol is a carcinogen. To reduce your risk of many cancers – including bowel cancer – drink less or stop drinking altogether. The NHS offers plenty of tips on how to cut down on alcohol.

‘Smoking increases the risk of bowel cancer by 60% and it’s most common in the 35-44 year old age group. Cigarette smoke contains over 7,000 noxious chemicals, at least 70 of which are known carcinogens. These enter the body via the lungs. They inhibit the body's normal cellular repair mechanisms and lower the immune response. Smokers tend to have more colonic polyps, which is where bowel cancers often arise. Heavy smokers have a significantly increased bowel cancer risk.

‘Stopping smoking is the best thing you can do for your health and to lower your risk of bowel cancer. The NHS offers free stop-smoking help and advice. It’s never too late to stop smoking.’

There’s a few lesser-known things you can do, too. Research is emerging that suggests a link between Vitamin D deficiency and bowel cancer risk. ‘Around 50% of the UK population has low vitamin D levels,’ says Dr Lee. ‘This is a particular issue in the winter from October to the end of March when the days are short and dark and the sunlight is weak.

‘Vitamin D is needed for the regulation of the immune system, and if this is not functioning well, bowel cancer risk is elevated. Vitamin D is essential for normal cell growth and development, so low levels mean cell growth and repair become disrupted. Higher levels of vitamin D help lower levels of inflammation.

‘There is no definitive recommendation that taking vitamin D supplements will reduce your risk of bowel cancer, but there are many good health reasons for doing this. The NHS recommends 10 mcg (400 IU) per day for all. There are separate recommendations for babies and children. It is especially important for anyone with dark skin or who has to cover up with clothing. Some now recommend vitamin D all year round and at a higher dose. Anyone with concerns should speak to their GP.’

Welcome side effects

In addition, certain medicines are offering a surprising barrier to the development of bowel cancer. ‘Recent research from a large Aberdeen study, that took place over 35 years, has shown that taking the Combined contraceptive pill for any length of time reduces the risk of bowel cancer by 19%. Other studies have reached similar conclusions,’ says Dr Lee. ‘Taking continuous combined HRT has also recently been shown in a large Norwegian study, to reduce the risk of bowel cancer by 20-30%. Again, other studies have reached similar conclusions.

‘The exact reasons for these findings are not known. However, oestrogen is known to play an important role in apoptosis – the destruction of cancer cells. It also lowers inflammation in the gut wall and helps keep the junctions at mucosal surface barriers closed and tight, helping prevent 'a leaky gut'. It also plays an important role in the immune system.

‘Note that the pill and HRT should not be taken for the purpose of primary prevention of bowel cancer. But it is comforting for women to know, especially if they are at risk of bowel cancer, that they can safely use oestrogen-containing contraception and HRT.’

Much of our protection against diseases such as bowel cancer is in our own hands, so don’t delay in making those lifestyle changes that will serve you well in the future. As Dr Rakshit says in the box below, small adjustments make a big difference. Start with a fibre-filled breakfast and a big glass of water, maybe walk into town a couple of days a week instead of getting the bus… Tiny choices like this all add up to give you optimal health and a fighting-fit immune system.

This video by Bowel Cancer UK shows Dr Anisha Patel talk about the symptoms of bowel cancer

Photos: Getty

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