Colorectal Cancer Prevention
You can seriously diminish the chances of getting colorectal cancer by taking some precautions.
Identifying Protective Factors
Although our genes and age influence our risk of cancer, most of the difference in cancer risk between people is due to factors that are not inherited. You might be able to ‘protect’ yourself and to lower your risk of colorectal cancer by managing some of the risk factors that you can control.
The best protective factor is to get yourself screened regularly!
Avoiding tobacco products, staying at a healthy weight, staying active throughout life, and eating a healthy diet may greatly reduce a person’s lifetime risk of developing or dying from cancer…
‘Healthy living’ is not a cast-iron guarantee against cancer. But it stacks the odds in your favour, by reducing the risk of developing the disease.
In the same way, careful drivers cannot guarantee that they will never get into an accident due to events beyond their control, but they are much less likely to do so than reckless ones…
These same behaviors are also linked with a lower risk of developing heart disease and diabetes.
Make Lifestyle Changes to Reduce Your Risk
You can take steps to reduce your risk of CRC by making changes in your everyday life.
You can reduce your risk of developing colorectal cancer by making healthier lifestyle choices. Scientists have estimated that ~50% of bowel cancer cases in the UK alone could be prevented through:
- being a healthy weight
- eating well
- being physically active
The World Cancer Research Fund International (WCRF) is a not-for-profit organization that analyses up to date global research on how diet and physical activity is related to cancer prevention. They produced a report which was reviewed in 2018 on the link between diet, physical activity and colorectal cancer. Their recommendations outlined below allow us to make practical changes to our lifestyle to reduce our risk of developing cancer, including colorectal cancer. Avoiding or stopping smoking is the biggest lifestyle change you can make.
There is strong evidence that being more active can reduce your risk of colorectal cancer by changing the levels of some hormones in your body (including oestrogen and insulin), helping to move food through your bowel quicker, helping to maintain your body weight by burning extra calories, reducing your body fat level and helping to control levels of inflammation in the bowel. It can also improve your long-term health and make you feel more energised.
Tips to increase your activity level:
Do smaller, more regular ‘chunks’ of 10-15 minute exercise sessions during the day. Then aim to build this up to the recommended target. Walk, jog or cycle some of the journey to or from work. Choose an activity you enjoy and find a friend to do it with you to keep it fun. Why not get a dog or borrow one to bring for walks? Go for a walk, jog, swim or gym class during your lunch break. Try to be more active whenever you can with little changes like taking the stairs instead of the escalator, walking at a faster pace and walking or standing while on the phone. Having a goal is a great incentive, so why not sign up to a running group or challenge yourself to do a 5km, 10km run or half marathon? Start small and then keep on challenging yourself – you are stronger than you think!
Whole grains are the seeds of cereal plants including wheat, rye, barley, oats and rice. There is strong evidence that eating plenty of wholegrains and dietary fibre can reduce your risk of colorectal cancer. A review of 6 studies which included 8,320 people showed that eating 90g of wholegrains every day reduces the risk of bowel cancer by 17%! Fruit and vegetables also contain fibre and a range of different vitamins, minerals and antioxidants so choose all colours of the rainbow to get the most benefit! Wholegrains and fibre can protect us against cancer as they are rich in vitamins and minerals, can bind to other compounds that can cause cancer stopping them from causing damage, help regulate our blood sugar levels, dilute the contents of our poo and help us to open our bowels more often. This reduces the time that toxins are in contact with the lining of our bowel, therefore reducing the risk of damage.
Tips on how to increase your intake of wholegrains, fruit and vegetables:
Choose high fibre cereals such as All Bran, porridge, Fruit and Fibre, Weetabix or homemade granola with lots of nuts and seeds for breakfast. Porridge is also a good option. Add fresh fruits to your breakfast cereal such as banana, berries, dried cranberries or raisins. Choose fresh fruit, a handful of nuts or seeds, an oat-based cereal bar, oat or wholegrain rice cakes or crackers with nut butters or salad as a snack. Mix nuts, seeds and fruit into yogurt. Have a wholemeal sandwich at lunch with carrot sticks and hummus or fruit after. Try homemade vegetable soup with rye bread – make a large batch and freeze it. Have brown pasta/rice/spaghetti with a variety of vegetables at dinner time. Add pulses and beans to dishes instead of red meat. Eat sweet potato and white potatoes with the skins on as most of the fibre is found in the skin.3. Be a healthy weight and as lean as possible – Aim to have a healthy weight and body mass index (the healthy BMI range is between 18.5-24.9kg/m²).
There is strong evidence that having a high level of body fat and being overweight or obese can increase the risk of colorectal cancer. When people are overweight or obese, there is more insulin present in the body and more fat cells which can stimulate the body’s inflammatory response and promote the growth of cancer cells. Being a healthy weight also reduces your risk of other chronic health conditions such as other cancers, heart disease, diabetes and stroke. It is easy for your weight to gradually creep up as eating just 100 calories per day more than you need can increase your weight by around 11lbs a year! Your BMI is based on your height and weight and can be worked out by dividing your weight in kilograms by your height (in metres) squared.
Tips to lose weight:
Aim for a steady realistic weight loss of 0.5 – 2lbs per week
Start the day with a healthy breakfast option and aim for three regular meals per day.
Increase your intake of wholegrains, fruit and vegetables as these foods are high in fibre which keeps you feeling fuller for longer and are lower in calories so make healthy snacks.
Minimise your alcohol intake or avoid it completely as it provides ‘empty calories’.
Do regular physical activity as outlined above to burn off extra calories to aid weight loss.
At mealtimes, aim to have ½ your plate filled with salad/vegetables/fruit, ¼ filled with a lean protein food (eg. grilled, baked or poached chicken/fish/turkey/eggs) and ¼ filled with a wholegrain carbohydrate food (brown or wholegrain bread/pasta/rice/spaghetti/potatoes with skins on). Watch you portion sizes!
Aim to drink 2L of fluid per day. Avoid high calorie/sweetened/full sugar drinks and choose water or low calorie/diet versions of squash or fizzy drinks or tea/coffee without sugar instead. Limit fruit juice to one 150ml glass per day and choose ‘skinny’ hot milky drinks where possible.
Keep a food and activity diary and monitor your weight weekly to track your progress and keep you focused.
Make two or three realistic changes to begin with (eg. I will have 3 portions of fruit every day) and once these become a habit, make another small change.
The occasional slip up is normal – just start again to get back on track.
Calcium is important at all ages for strong bones and teeth. Adults need 700mg of calcium per day and this is higher in people with other conditions like osteoporosis. There is strong evidence that consuming dairy products can reduce the risk of colorectal cancer.
Tips to get enough calcium:
Aim for 3 portions of dairy per day such as 200ml glass of milk, a matchbox sixe of cheese and a medium 120g pot of yoghurt.
Choose low fat options, as they have the same calcium content but less calories if you are trying to lose weight.
Choose calcium enriched products wherever possible, including lactose-free alternative products (rice/oat/almond/soya milk and yoghurt), bread and cereals.
If you dislike dairy products, eat more fish and calcium fortified cereals and bread. You may need to consider taking a calcium supplement if you cannot get enough calcium from your diet.5. Drink alcohol in moderation, if at all
There is strong evidence that drinking >30g or 2 drinks of alcohol per day causes colorectal cancer. Any increase in alcohol intake can increase the risk of cancer so try limit it as much as possible. It is thought to cause cancer as it is broken down into a chemical called acetaldehyde by our liver which can damage cells, it can induce oxidative stress through increased production of reactive oxygen species which damages our cells, increases levels of hormones, can increase the absorption of other cancer-causing chemicals such as tobacco and can interfere with our body’s ability to repair our DNA or genes. Alcoholic drinks contain a lot of calories too so this can contribute to weight gain and more body fat which we know is strongly linked to increasing cancer risk. One large 250ml glass of wine contains about 190 calories which is similar to a butter croissant or packet of crisps!
Tips to cut down on alcohol:
Set a limit for how much alcohol you will drink or money you will spend on a night out Alternate between an alcoholic and non-alcoholic drink (eg. have a glass of water or diet soda drink in between). Use diet versions of drinks to mix with spirits and dilute it more than usual. Try white wine as a spritzer mixed with sparkling water or add soda water and a no-added sugar lemon or lime squash to gin. Try to reduce the size of your drink – choose a half pint, small can, small glass or single measure. Use a smaller wine glass. Sip your drink slowly to make it last longer. Let friends and family know if you are trying to cut down so they can support you.
There is strong evidence that eating processed meats (such as bacon, sausages, chorizo, ham, salami, burgers) can increase your risk of colorectal cancer. This may be due to the nitrates and nitrites that are added to foods to preserve them which are broken down into harmful compounds by our body which can cause cancer. Eating too much red meat can also be harmful as haem, the compound that gives meat its red colour, can also be broken down in our body to form cancer causing compounds that could damage the lining of our bowel.
Tips to reduce our processed and red meat intake:
Aim for no more than 3 portions of red meat per week (~ 350–500g cooked weight). One portion is about size of the palm of your hand. Use more beans, pulses, lentils, poultry, eggs, fish and tofu instead. Keep some days meat-free.
Following a healthier lifestyle including a healthy balanced diet, regular physical activity and being a healthy weight can improve your overall health as well as reduce your risk of cancer, so try to make small changes using the tips and advice above that you can continue long term within your day to day life.
Other protective factors
Some medications have been found to reduce the risk of precancerous polyps or colon cancer. However, not enough evidence exists to recommend these medications to people who have an average risk of colon cancer. These options are generally reserved for people with a high risk of colon cancer.
For instance, some evidence links a reduced risk of polyps and colon cancer to regular use of aspirin or aspirin-like drugs.
There is some evidence that long-term use of aspirin lowers the risk of developing non-cancerous growths (polyps) and colorectal cancer. Studies have shown that taking aspirin lowers the risk of colorectal cancer and the risk of death from colorectal cancer.
Aspirin may also benefit people who have already been diagnosed with CRC that has not spread to other parts of the body. A small number of studies have found that it reduces the risk of colorectal cancer coming back after treatment.
More information is needed about how aspirin works to lower the risk, who it might help, what dose is best and how long people should take it for.
Aspirin can cause (serious) side effects. The possible harms of aspirin use (100 mg or less) daily or every other day include an increased risk of stroke and bleeding in the stomach and intestines.
Talk to your GP or medical team first, if you’re thinking of taking aspirin. They can advise you on the safety of aspirin and whether it might benefit you.