More than one in two people will develop some form of cancer during their lifetime. It can occur at any age but it is rare in the young. Half of those diagnosed with the condition in Ireland are aged 68 or over.
There are more than 200 types of cancer, the most common being skin, prostate, breast, bowel, and lung. While not all cancers can be prevented, the good news is that 30 to 50 per cent can.
By making lifestyle changes such as being active, not smoking, managing your weight, limiting alcohol, eating well, protecting your skin from the sun, and taking part in cancer screening, you can lower your risk of developing the condition.
There is clear evidence that physical activity and exercise can reduce your risk of breast, bowel, and womb cancer. It may also help prevent lung cancer, according to the Irish Cancer Society. And the health benefits do not just stop there, taking part in physical activity is one of the most important things you can do for your general health and wellbeing. It can help control your weight, reduce your risk of heart disease and diabetes, strengthen your bones and muscles, improve your mental health, and increase your chances of living longer.
So, how do we define physical activity and why is it important to incorporate more of it into our everyday lives? Professor Niall Moyna, a professor of clinical exercise physiology at the School of Health and Human Performance at Dublin City University, said a simple way of reminding us if we are physically inactive is if we are sitting, reclining, or lying down.
“If you are doing anything other than these three things, you’re probably physically active. Many work-related activities throughout the day involve physical activity such as gardening, playing with children, washing the car, doing the laundry, commuting to work, or shopping.”
Speaking at a recent webinar, organised by the Irish Cancer Prevention Network, he said current guidelines are that we should all get at least 150 minutes of moderate intensity aerobic physical activity a week. That’s the weekly equivalent of a brisk walk. Or at least 75 minutes of vigorous-intensity aerobic physical activity a week such as going for a cycle or a jog. The big question is does meeting these physical activity recommendations give you quantifiable protection against cancer?”
Nine large studies
An international study on the relationship between physical activity and cancer risk, whose findings were published in 2019, gave a resounding “yes” on many fronts to that question.
“It analysed nine large studies undertaken in the US, Europe, and Canada and involved over three-quarters of a million participants,” explained Professor Moyna. They were monitored for 10 years and the 50,000 cancers that occurred in the group during that period were analysed.
“The most important finding of this study was that achieving the recommended dose of physical activity was associated with a significantly lower risk for seven different types of cancer including liver, myeloma, non-Hodgkin’s lymphoma, kidney, endometrial, colon (in men ), and breast. That was a really, really, significant finding.”
The strength of the link between being physically active and cancer risk reduction varied depending on the type of cancer. “For example, if you met the recommended amount of physical activity, it reduced your risk of breast cancer from six to 10 per cent. In contrast, it reduced your risk of liver cancer from 18 to 27 per cent.”
In the case of some cancers, achieving the recommended daily physical activity level resulted in the following risk reduction: –
Myeloma [a blood cancer] – a 14 to 19 per cent reduction.
Non-Hodgkin’s lymphoma (in women ) – a 11 to 18 per cent lower risk.
Kidney disease – a 11 to 17 per cent reduction in risk.
Endometrial cancer (cancer of the womb ) – a reduced risk of 10 to 18 per cent.
Colon cancer (in men ) – an eight to 14 per cent lower risk.
He said it is common in terms of fitness to assume more is always better. However, this research challenges that notion.
“Two different patterns were identified. For some cancers, the [cancer risk reduction] benefit kept increasing – the more activity you did, the greater the benefit you got. The risk for breast, colon, endometrial, oesophageal, and head and neck cancer continued to decrease as people engaged in physical activity even beyond the recommended daily levels. So, for these cancers, pushing further did yield additional benefits.
“In the case of breast cancer, if you go beyond the recommended levels you still get a decrease. We see the exact same thing for colon cancer – improved risk reduction with the more activity undertook.”
Began to plateau
However, for other cancers, the benefits began to plateau, according to the professor. “For kidney, gastric, liver cancers, and Non-Hodgkin’s lymphoma, particularly in women, most of the risk reduction was achieved by just attaining the recommended level of physical activity daily. Beyond that point, doing more was associated with little or any additional risk reduction.
“For other types of cancer, especially liver and kidney cancer, consistency at the recommended level is the most critical factor whereas [in relation] to the other cancers, the more you do [physical activity-wise] the more benefit you are going to actually accrue.
“The take home message from the study is there is now robust evidence to recommend 150 to 300 minutes of moderate intensity physical activity or 75 to 150 minutes of vigorous intensity physical activity per week to lower the risk of at least seven distinct cancers. For several cancers, additional benefits may be gained from activity levels exceeding the minimum recommendations.”
Research has also consistently linked physical activity after cancer treatment to a lower recurrence of the condition and increased survival, he said.
Dr Emer Guinan, an associate professor in cancer rehabilitation and survivorship at Trinity College Dublin, said it is important to remember that physical activity is not just exercise. “It refers to any bodily movement produced by skeletal muscles that require energy expenditure.”
This can include any form of exercise such as walking, running, cycling, or playing sport or household chores such as cleaning, gardening, vacuuming, doing the laundry, or washing the car.
If your occupation or leisure time is sedentary and you spend a lot of time sitting at a desk each day or relax in the evenings by watching television, consider ways to include increased activity in your lifestyle.
Commuting time
“Can you use your commuting time to incorporate some physical activity into your day? For many people who are busy, this is one of the key opportunities where you can embed physical activity in a purposeful way where you are getting from A to B. You probably just need that little bit of extra time to do it.
“Remember, every move counts. It doesn’t have to be big walks, big runs, or big gym sessions. If we know that physical activity is important, why don’t we just move more? A change in behaviour, such as increasing your physical activity isn’t easy. We need to acknowledge that and reflect on what are the barriers/factors limiting you from being more physically active.”
Lack of time, energy, motivation, social support, and skill may be some of the reasons holding you back, she said. Fear of injury, lack of facilities, weather conditions, and high cost are other influencing factors.
“It is important to set yourself up for success, that your goals are achievable and practical. If you are in a house, for example, where everyone else is physically active, it may be easier for you to be active, too. If that’s not the case, you are starting from scratch.
“Fear of injury, particularly if you had a bad experience and were injured after becoming physically active and are fearful of that happening again, can be a barrier. Or, if you’ve had an illness and are returning to physical activity, you may be not sure where to start.”
Get physically active
Aim for at least 150 minute of moderate intensity physical activity or 75 minutes of vigorous intensity activity during the week. Moderate physical activity makes you a little out of breath but you can talk comfortably. Vigorous activity will raise your heart rate, make you sweat, and feel out of breath.
Practical tips to incorporate movement
At work
• Walking meetings. Consider these if the topic is not overly formal.
• Active transport opportunities. Can you walk to work rather than taking the bus or park further away and walk the latter part of the journey?
• Micro breaks. If you work in a sedentary job, try to get up and go for walks. If you are working from home, try to move around the house regularly or do exercises.
At home
• Gardening. This is a good way to get physically active.
• Household chores. Everything from dusting, vacuuming, doing the laundry, cooking, and tidying involves movement.
• Active holidays. These are a way to put your leisure time to good use.
