Cut your risk of colon, womb and breast cancer
If you are physically active, you will reduce your risk of getting these cancers:
- Colon (large bowel)
- Endometrial (lining of the womb)
- Post-menopausal breast cancer.
Activity is beneficial even if you lose no weight
Physical activity will help prevent these cancers even if you don’t lose any weight.
Of course, physical activity can also help you to avoid gaining weight. Being a healthy weight has the extra benefit of reducing your risk of other cancers, including:
- Food pipe (oesophageal)
- Gall bladder cancers
Healthy lifestyle reduces your overall risk
You can reduce your risk of all cancers by 18% if you follow all the recommendations for a healthy lifestyle, which are to:
- Be moderately active for at least 30 minutes per day
- Be a normal body weight (a body mass index [BMI] between 18.5 and 24.9)*
- Avoid foods that promote weight gain, such as sugary drinks and fast foods
- Breastfeed (for women)
- Eat mostly food that comes from plants
- Don’t smoke
- Limit your intake of red meat
- Avoid processed meats
- Limit your consumption of alcoholic drinks.
What is a healthy body weight? Do I have a healthy body weight?
A healthy body weight is one that makes you least likely to develop the several conditions that having too much body fat can cause – especially some cancers, but also heart disease and diabetes, among others.
Being too thin or too fat can be unhealthy, so you should aim to be within the healthy range of body weight. Experts have developed an index called the body mass index (BMI) that takes your height and sex into account, to work out if you are a healthy weight.
For the mathematically minded, it is the weight in kilograms divided by the height in metres, squared – this is the body mass index, or BMI. If you weigh the right amount for your height then you can reckon that you are a healthy weight, unless you are particularly tall, short or muscular.
Click here for an example of one BMI calculator that you can use to work out if you are a healthy weight
How to keep active and help prevent cancer
It can be easier than you think to increase your activity levels, even if you don’t do much at the moment. Making small changes, like taking the stairs instead of the lift or making short journeys on foot, can really help increase how active you are. And it’s never too late to start making a difference. Even if you’ve been inactive for years, becoming more active can improve your health and reduce the risk of cancer.
30 minutes a day, five days a week
You should aim to do at least two and a half hours of moderate activity every week. This is the same as 30 minutes on five days of the week.
- You don’t have to do it all in one go. All the bits you do throughout the week add up. Just 10 minutes at a time can count.
- You can build up the amount of activity you do steadily over time.
- There’s no need to join a gym or train for a marathon, unless you want to.
- The more active you are, the greater the benefits you can gain.
What counts as moderate activity?
Activity doesn’t just mean sport and exercise. Anything that makes you a bit warmer and slightly out of breath counts as moderate activity, including:
- Cycling or brisk walking
- Heavy gardening
- Household tasks like vacuuming or DIY
- Kicking a ball in the park
- Family games like chasing.
In addition to this moderate activity, you should generally try to be as active as possible. This means you should avoid too much sedentary behaviour like sitting or lying down for several hours per day. You can get a lot of benefit from light activity. Simply not being sedentary can boost how many calories you burn.
Generally speaking, the more time you spend being physically active, the better. Do as much light activity as possible, like:
- Light bicycling
- Climbing the stairs
- Doing housework
- Taking part in leisurely sports like table tennis or golf.
Building up even small amounts of physical activity throughout the day will benefit you.
If you are unsure about taking part in any activity, ask your doctor.
Physical activity for children and young people
Children and young people should do at least 60 minutes of moderate- to vigorous-intensity physical activity every day. They can spread this through the day, for example, two sessions of 30 minutes each.
How can I make being active a habit?
Studies show that once we make healthy behaviour a habit, it’s much easier to stick to in the long term. To help you form healthy habits, try linking activity to a particular point in your day, like regularly walking to the station or bus stop in the morning, or meeting friends for a walk every Tuesday evening.
How can I keep myself motivated?
It might help to set a goal for yourself, either on your own or with friends or family. You could aim to take part in a charity event like doing the Women’s Mini Marathon on behalf of the Marie Keating Foundation. Or you could use a pedometer (gadget or phone application that counts your steps) and challenge yourself to increase the number of steps you want to take in a day.
Once you’ve set a goal, tell others about it. They can help you stick to your plans, keep you motivated, or even keep you company if you’re going for a walk, jog or cycle ride.
How does physical activity help prevent breast and womb cancer?
A 2010 study into physical activity and womb cancers, found that physical activity was clearly associated with reduced risk of the most common type of womb cancer – endometrial (lining of the womb) cancer. Active women had around 30% lower risk than inactive women.
This is because being physically active can change the levels of some hormones, including oestrogen and insulin. Hormones are chemical messages that get carried around our bodies in our blood. They help tell our bodies and cells what to do.
In women, physical activity can lower the level of oestrogen. Oestrogen is thought to fuel the development of many breast and womb cancers, so reducing the levels of this hormone could help to reduce the risk.
Activity can also reduce the amount of insulin in our blood. Insulin is very important in controlling how our bodies use and store energy from food. Changes in insulin levels can have effects all over the body. And scientists think insulin can turn on signals that tell cells to multiply. Because cancer starts when cells multiply out of control, lowering insulin levels could help stop some types of cancer from developing.
How does physical activity prevent bowel cancer?
Studies from around the world show that people who do the most physical activity can cut their risk of developing cancer of the large bowel (colon) by about a quarter. Being active seems to cut the risk of cancer developing in any part of the colon (which accounts for around two thirds of all bowel cancers). But it may not have any effect on the risk of rectal cancer.
This is because physical activity helps food move through our bowels. When food moves through our bowels quickly this reduces the amount of time that the inside lining of the bowel is in contact with any harmful chemicals, like those released when you consume alcohol or red and processed meat. So there’s less chance of them being able to cause damage that could lead to cancer.
Being active also helps control levels of inflammation in the bowel. Inflammation is a normal part of the way our bodies react to injury or infections. But it can sometimes cause even more damage, particularly when it keeps happening in the same place. This can lead to the cells multiplying much more frequently than usual, to replace dead and damaged cells, increasing the chances of mistakes that could lead to cancer.
How does physical activity benefit cancer patients?
There is also good evidence that being active can help people during and following cancer treatment. If you are a cancer patient and want to be more active, discuss with your doctor what would work best for you.
A DCU programme for cancer survivors, Move On, has been shown to significantly improve participants' body mass index (BMI), cardiorespiratory fitness, flexibility and strength.
You can read more about the link between exercise and reducing your cancer risk in this section which is an interview with Mairead Cooney, a clinical exercise physiologist specialising in Chronic Illness Rehabilitation and a postgraduate researcher and in DCU’s MedEx programme.
Hear from Dermot, a cancer survivor, about how he integrates exercise into his everyday life.