Posted on June 16, 2015 by Jenny Cromack

Can exercise assist in the prevention of cancer? This is a huge question and when you search this term it brings up over 500,000 journal articles!

In reality it appears that exercise might be cancer specific, so rather than discuss cancer as a generic disease during this blog, we’ll approach the question, can exercise assist in the prevention of cancer, from the standpoint of specific forms of cancer.

 

We will use the top three forms of cancer in the UK.

1. Breast Cancer- 50,000 diagnoses per year
2. Lung Cancer- 43,465 diagnoses per year
3. Prostate Cancer- 41,736 diagnosis per year

The list goes on…. a study conducted by Ahmad AS, Ormiston-Smith N, Sasieni PD (2015) studied trends in the lifetime risk of developing cancer in Great Britain. The shocking statistic are:

• 1975= 1 in 4 people were diagnosed with some form of cancer
• 1990s= 1 in 3 people were diagnosed with some form of cancer
• 2010= 4 in 10 people (almost 1 in every 2) were diagnosed with some form of cancer.

I’m sure you will agree, this is a scary increase!

BREAST CANCER: Let’s begin with answering the question of ‘Can exercise assist in preventing breast cancer?’

The following information was found in recent studies. Lynch, Neilson and Friedenreich (2010) examined physical activity and its implications on the prevention of breast cancer, the study reviewed 73 research papers from across the world. The key points from the paper were as follows:

• Across the studies there was a 25% average risk reduction amongst physically active women, compared to the least active women in the studies.
• The association with  reduced risk was strongest in those that had sustained physical exercise over their lifetime
• The reduced risk was strongly correlated to when exercise intensity was moderate to vigorous, compared to light.
• The review also suggested that studies seem to show a trend for a stronger effect of physical exercise in the prevention of breast cancer in post menopausal women.

The mechanisms of the preventative affect physical activity may have on breast cancer are vast, the researchers propose that it is likely multiple factors effecting biologic pathways, including, sex hormones, insulin resistance, and chronic inflammation.

LUNG CANCER: Although commonly associated with smokers, often individuals fail to associate a link between a sedentary lifestyle, poor nutrition and obesity and developing this form of cancer. Kigali et al., (2012) compiled research and produced an authorative review on the matter, here are the key points:

• Cigarette smoking is the most important risk factor in the development of lung cancer
• 10 studies showed an inverse relationship between lung cancer and exercise
• 11 studies showed no relationship between physical activity and lung cancer
• A meta analysis conducted between 1996- 2003 showed that greater levels of leisure physical activity prevents breast cancer.

Unlike breast cancer where there is a key link between breast cancer prevention and physical exercise, lung cancer appears to be more controversial. However it may be that factors such as nutrition, and smoking, alcohol intake are greater influences. Indeed there has been a substantial amount of research showing a strong inverse relationship between fruit and vegetable consumption and lung cancer.

PROSTATE CANCER: Chen et al., (2011) recently completed a meta-analysis examining whether physical activity reduces the risk of prostate cancer. The study was based on 88,294 cases compiled from 19 cohort studies and 24 case control studies.  Here are the key points from the research review

• Frequent physical activity reduced the likelihood of developing prostate cancer in men aged 20-45 years
• Frequent physical activity reduced the likelihood of developing prostate cancer in men aged 45-60 years
• No effect was observed of physical activity for men aged <20 or >65 years.

In summary the findings are quit mixed in terms of the development of cancer, there currently are no specific guidelines that are commonly accepted regarding, intensity, mode, frequency or duration of physical exercise. However there is a clear link that it does overall improve the likelihood of not developing the disease.

We often get so fixated on the scales and forget about all of the other amazing benefits exercise can bring to us. So from a pure health perspective achieving 15-20 minutes a day of moderate to vigeorus exercise could make the the difference to your long term health. It will be no good starting in 10 years time, lay the foundations now to a healthier life.