Study claims boosting fitness slashes prostate cancer risk by 35%

By James Gamble via SWNS

Improving physical fitness can reduce the risk of developing prostate cancer by more than a third, according to a new study.

Researchers found those who upped their annual cardiorespiratory fitness (CRF) by three percent or more were up to 35 percent less likely to develop prostate cancer.

The Swedish team behind the research hope their study, published in the British Journal of Sports Medicine, will encourage men to improve their fitness in a bid to steer clear of the disease.

There are relatively few known risk factors for prostate cancer, which accounts for nearly 15 percent of all cancer deaths in males in the UK and killed more than 12,000 men across the nation in the two years between 2017 and 2019.

King Charles has just undergone surgery for an enlarged prostate, though it has not been disclosed whether he had cancer.

Whilst there’s existing evidence as to the beneficial effects of physical activity on the risk of several cancers, associations with prostate cancer are less clear-cut.

The majority of previous studies have assessed fitness only at a one-time point, and none have looked at the potential impact of fitness on both the risk of developing and dying from prostate cancer.

Therefore, researchers from the Swedish School of Sport and Health Sciences (GIH) sought to discover whether improvements in men's fitness could offset the risk of developing the disease.

They analyzed data from a national occupational health profile in Sweden, containing information on physical activity, lifestyle, perceived health, measurements of body mass and height, and the results of at least two CRF tests.

The tests measured the fitness of the 57,652 Swedish men as they peddled on a stationary cycle.

Annual cardio fitness was measured as absolute and relative VO2 max - relating to the amount of oxygen the body uses whilst exercising as hard as possible.

The participants were then divided into groups according to whether their fitness levels had increased annually by more than three percent, fell annually by more than three percent or remained stable.

To assess whether changes in fitness on prostate cancer risk varied by baseline fitness, three equally sized groups of low, moderate and high CRF were created.

All participants were monitored from the date of their last assessment to the date of their prostate cancer diagnosis, their death from any cause or until 31 December 2019 - whichever came first.

During an average period of nearly seven years, the researchers saw that 592 men - one percent of the total sample - were diagnosed with prostate cancer and 46 (0.08 percent) had died of their disease.

They also found that an annual percentage increase in absolute cardiorespiratory fitness was associated with a two percent lower risk of prostate cancer - but not death - after accounting for potentially influential factors such as age, education level, year of test, weight (BMI), and smoking status.

When the participants were grouped according to whether their cardiorespiratory fitness had increased, remained stable or fallen, those whose fitness had improved by three percent or more a year were found to be more than a third (35 percent) less likely to develop prostate cancer than those whose fitness had declined, after accounting for potentially influential factors.

When the participants were grouped by their cardiorespiratory fitness at their first assessment, the association between fitness and a reduction in prostate cancer risk was only statistically significant (15 percent lower) for those with a moderate level of fitness at the start of the study.

However, as the study was purely observational, it was unable to establish causal or genetic factors that have a major role in both a person's cardiorespiratory fitness and cancer risk.

But Dr. Kate Bolam, a lead author from the Department of Physical Activity and Health at GIH, said her team's study nevertheless suggests a link between staying fit and warding off prostate cancer.

"This is the largest study to examine the relationships between change in CRF (cardiorespiratory fitness) and cancer incidence and mortality, and the first study to examine change in CRF specifically on prostate cancer incidence and mortality," Dr Bolam explained.

"Individuals with an annual increase in absolute CRF by three percent or more had a significantly lower risk of being diagnosed with cancer compared with individuals whose CRF was stable.

“The results highlight the importance of cardiorespiratory fitness for prostate cancer risk, which has been challenging to determine with single time point studies.

“Improvements in cardiorespiratory fitness in adult men should be encouraged and may reduce the risk of prostate cancer.”