Exercise better than rest at slowing cancer

Exertion found to trigger muscles into producing proteins that suppress the growth of tumours

RESTING may seem like a good way to battle cancer, but a new study suggests that exercising could actually be better at fighting the disease.

Researchers at Edith Cowan University, in Australia, have discovered that exercising triggers muscles into producing proteins that suppress tumour growth and actively fight cancerous cells.

In a clinical trial, 10 prostate cancer patients aged between 73 and 78 were asked to undergo exercise training for 12 weeks, and blood samples were taken before and after the programme.

When the samples were applied on to living prostate-cancer cells, the postexercise blood suppressed the growth of tumours by 22 per cent over 72 hours.

The post-exercise blood was found to contain far more anti-cancer proteins known as myokines.

Prof Robert Newton, the study supervisor of ECU’S exercise medical research unit, said the results helped to explain why cancer progresses more slowly in patients who exercise.

“The patients’ levels of anti-cancer myokines increased in the three months,” he said. “When we took their pre-exercise blood and their post-exercise blood and placed it over living prostate-cancer cells, we saw a significant suppression of the growth of those cells from the post-training blood.

“That’s quite substantial, indicating chronic exercise creates a cancer-suppressive environment in the body. We believe this mechanism applies to all cancers.” Many studies have found higher levels of exercise linked to slower cancer progression, but scientists say it is the first time myokines have been shown to play a role in tumour-suppression.

Jin-soo Kim, doctoral candidate and research lead, said that while myokines could signal cancer cells to grow slower – or stop completely – they were unable to kill the cells by themselves.

However, he said myokines can team up with other cells in the blood to actively fight cancer.

“Myokines in and of themselves don’t signal the cells to die,” Mr Kim said. “But they do signal our immune cells – T-cells – to attack and kill the cancer cells.” The 12-week exercise programme involved supervised resistance training targeting major muscle groups, aerobic exercise and protein supplementation.

Patients undertook 300 minutes of exercise weekly, and were also asked to cut their calorie intake by between 500 and 1,000 calories per week.

All patients were being treated with androgen deprivation therapy which is known to cause weight gain and reduce lean muscle mass. The research showed that exercise also helped patients regain their muscle mass. Around 52,000 men are diagnosed with prostate cancer in

Britain each year and around 11,000 will die from the condition.

The team has started a new trial to see if a six-month exercise programme could be useful in patients with advanced prostate cancer.

“These men have high disease burden, extensive treatment side-effects and are very unwell, but they still can produce anti-cancer medicine from within,” said Prof Newton. “It’s important as it may indicate why men even with advanced cancer, if they’re physically active, don’t succumb as quickly.”

The research was published in