When bowel cancer specialist Dr Ravindhi Murphy begins treating a patient, she’s often asked the same question: ‘Why me?’
It’s a question that’s impossible to answer conclusively, she says. However, figures suggest that, in many cases, at least part of the explanation lies in something – or several things – that they ate.
Studies suggest that up to a third of bowel cancers – a disease that’s rising rapidly in young Britons- are related to diet and, therefore, may have been prevented.
‘What we eat is critical in shaping your risk of bowel cancer,’ says Dr Murphy. And it’s not just how much fibre we eat, and how little bacon we enjoy, that plays a key role.
‘Research is consistently showing that our microbiome – the trillions of bacteria in our gut – is key in either protecting us from bowel cancer, or driving it.
‘And much of the nature of this bacteria can be altered by the food we eat.’
So what exactly should our daily diets look like for the lowest risk of bowel cancer? Here, Dr Murphy offers suggestions for breakfast, lunch and dinner – and even a few snacks.
Combining chicken and vegetable curry with dahl and brown rice is a strong dinner choice
Bowel boosting breakfasts
Oats with yoghurt, fruit and nuts
Don’t be afraid to add more to your yoghurt bowls, Dr Murphy says. She recommends picking a base of Greek yoghurt and oats or porridge (made with whole milk) and adding a selection of gut-friendly additions like nut and seed mixes and fresh fruit such as banana, berries and grated apple.
‘Greek yoghurt is high in protein, and often contains live bacteria in it, adding to the collection of health-boosting bugs that drive your digestive system,’ she says.
‘Nuts and seeds add vitamins, minerals and healthy fats, and the fruit and oats add fibre, which is vital.’
A 2011 meta-analysis by Imperial College London involving almost 2 million people found that a high intake of dietary fibre such as whole grains, significantly reduced bowel cancer risk.
Specifically, for every 10g of fibre eaten there was a 10 per cent lessened chance of the disease.
Only around four per cent of Britons meet the recommended daily limit of 30g, studies show.
Two slices of wholegrain toast with peanut butter and sliced banana
This quick and easy breakfast will pack in up to 11g of fibre in a single meal, which is more than a third of your daily needs, Dr Murphy says.
Check the label for a nut butter with no added sugar or palm oil, she advises. Studies have shown that palmitic acid – a substance in palm oil – can reduce the diversity of gut flora.
According to a 2013 Irish study, bowel cancer patients generally have a less diverse culture of gut bacteria, compared to those without the disease.
‘The more plant-based foods you eat, the more diverse your gut bacteria is likely to be,’ says Dr Murphy.
As for what to avoid at breakfast, Dr Murphy advises steering clear of bacon and sausages.
‘Processed meats like bacon, sausages and some deli meats are a group one carcinogen which means that the evidence that they can cause bowel cancer is strong.’
Experts believe the danger lies with compounds in the meats called nitrites and nitrates which react with chemicals in the gut to trigger cancer-causing cell changes.
Lunches that keep you full and move toxins out the gut
Poached eggs with avocado and kimchi on toast
Dr Murphy recommends using seeded wholegrain bread as a base, and serving with a salad on the side to make this lunch extra filling.
Use half an avocado to save on calories. This still packs in around 10g of fibre, which is enough to help digested food move through the bowel, reducing the chance of a build-up of nasty toxic substances.
She also recommends ‘topping up’ meals, where possible, with a sprinkling of fermented foods, like kimchi, kefir, yoghurt and sauerkraut, all of which contain live microorganisms that can influence the mix of bacteria in the gut.
Specifically, these organisms help to produce short-chain fatty acids that can help maintain the bowel’s protective barrier and suppress the growth of abnormal cells, Dr Murphy explains.
Kimchi also adds another couple of grams of fibre, taking the total up to 12-13g.
Grain bowl with vegetables
Using quinoa and chickpeas as a base, Dr Murphy advises adding as wide a variety of vegetables as possible to get a broad range of anti-inflammatory compounds.
For a dressing she recommends lemon juice, extra virgin olive oil, and fresh herbs such as parsley.
Adding grilled chicken or salmon will boost protein and keep you full for longer, but Dr Murphy says high protein is not a great concern for reducing bowel cancer risk.
A 2022 Harvard study found those who ate a diet consisting predominantly of whole grains, vegetables, fruits and legumes like chickpeas had a 14 per cent lower risk of developing bowel cancer, compared to those on high-protein diets.
While red meat like beef has, in some studies, been shown to increase bowel cancer risk, although Dr Murphy says the data is far less convincing than it is for processed red meat.
‘Red meat has some health benefits,’ she says. ‘It contains vital micronutrients like iron, zinc and vitamin B12, so it is part of a healthy diet, but we shouldn’t be eating it every day.
‘Stick to a maximum of three portions a week and it’s best to choose lean cuts rather than fatty.’
Dinners that deliver the bulk of daily fibre needs
Salmon with garlic butter, lemon and asparagus
The garlic here contains prebiotics that feed good gut bacteria, while salmon is rich in omega-3 fatty acids, which reduce gut inflammation, says Dr Murphy.
She also recommends serving this with a side of roasted asparagus, broccoli, or sweet potato – which count towards your five-a-day, or the recommended thirty plants per week to keep gut microbiome diverse.
‘If you’re cooking from scratch you are much more likely to get enough fibre compared to if you’re eating processed foods from a packet,’ she says.
She adds that vegetables needn’t always be fresh; canned or frozen are a nutritious and budget-friendly way to up your plant intake.
Chicken curry served with dahl and brown rice
Poach a chicken breast in coconut milk with added turmeric, ginger and garlic, before adding vegetables like broccoli and spinach, Dr Murphy suggests.
‘Turmeric and ginger are known for their anti-inflammatory properties, while coconut milk provides healthy fats to nourish gut cells.
‘Dahl is excellent for gut health as lentils are packed with fibre.’ In fact one bowl of dahl contains 12g – more than a third of the recommended intake. When added to this curry the total fibre count sits at an impressive 20g.
Dr Murphy says this meal is particularly bowel health friendly as it combines soluble fibre (in the lentils) with insoluble fibre in rice and vegetables.
Both types are vital. Soluble fibre acts as food for the gut microbiome, while insoluble fibre helps keep the digestive system moving.
The ultimate anti-bowel cancer diet keeps alcohol to a strict minimum, she says.
A 2017 review by researchers at Imperial College London found alcohol increased the risk of bowel cancer by 7 per cent with every additional 100ml of wine drunk per day.
What about snacks?
Dr Murphy says we’ve long been taught that snacking is an unhealthy habit that will ruin our appetites – but this isn’t strictly true.
As long as you’re eating foods that are feeding your gut bacteria and aren’t packed full of calories, there’s nothing wrong with a small bite between meals.
She recommends a crudite and humous plate, sliced apples and pears with nut butter and, for those craving something sweet, a handful of dried fruit like prunes or raisins.
‘Wash it down with a glass of kefir,’ she adds. ‘You can get the fermented yoghurt at most supermarkets now. Studies have shown it can reduce inflammation in the gut.’
