68 | Cycling World
Healthy Riding
Prostate Health and Cycling -Is There a Link ?
The debate whether cycling affects prostate health has taken renewed vigour recently since the publication of a study involving 5000 male cyclists . Professor Robert Thomas , a Prostate Cancer Oncologist , examines further
The recent study into prostate health reported a six-fold increase in prostate cancer among men cycling more than 8 hours compared to those cycling less than 3.75 hours a week1 . Every statistician knows , however , this was only an association and does not prove causation especially as men were more likely to volunteer for the study if they or a relative had cancer , making it fundamentally biased . It is also known that cycling can increase the PSA blood test for 24 hours , so frequent cyclist are more likely get referred for investigation2 . What was not highlighted in the media was that men in the study had a prostate cancer rate , which was three times less than the general population . This would be expected as there are over 180 beneficial biochemical changes that occur after exercise , which reduce the risk of cancer by protecting our DNA , blocking cancer growth and spread4 .
How cycling could reduce the risk of prostate cancer ?
Indirectly mechanisms – reduces obesity , improves psychological health and vitamin D levels which are all linked to lower cancer rates4 .
Direct mechanisms – improved insulin sensitivity , lowering growth cytokines such as Insulin like Growth Factor ( IGF ); increased natural killer cells and lymphocytes , which improve immune recognition of cancer cells ; reduced markers of inflammation such as prostaglandin 2 .
Unfortunately there are always two sides to a debate . There are some factors , specifically related to cycling , which could potentially have an influence on prostate cancer risk , albeit , yet to be proven :
How could cycling increase the risk of prostate cancer ?
Prostatic inflammation ; Repetitive compression and trauma to the perineum leading to recurrent inflammation of the prostate , has been reported to be higher in cyclists3 . Chronic inflammation is known to be a risk factor for malignancy2 .
Testosterone increases immediately after intense exercise , which could encourage early prostate cancer cells to grow3 . This increase , however , only occurs in the first 15-60 minutes unless banned anabolic steroids are taken and rarely occurs in men over 55 years .
Generation of free radicals . Strenuous exercise , particularly if unaccustomed , produces reactive oxidative species ( ROS ) that damage DNA , the first stage in cancer initiation and progression3 .
Lifestyle factors to increase prostate health
First , don ’ t stop cycling , as over time , with sensible training methods , adaptive processes reduce testosterone levels even below normal . Likewise , anti-oxidant enzymes , such as superoxide dismutase are up regulated to compensate for the increase in ROS . Nevertheless , this highlights the importance of boosting the diet with anti-oxidant rich foods , which enhance the formation of anti-oxidant enzymes or mop up free radicles directly . As well as a comfortable saddle ; it would be sensible to consider diets , which reduce chronic inflammation , particularly cutting out refined sugars ; avoiding carcinogens such as acrylamides formed by super heating carbohydrates ( crisps ,