Grant title: The impact of dietary energy restriction versus exercise on prostate tumour and muscle tissue protein synthesis in vivo in prostate cancer patients
In our WCRF-funded project we are excited to actually measure (prostate) tumor protein synthesis rates in vivo in patients. Furthermore, we set the first steps to assess whether lifestyle interventions (energy intake restriction and exercise) can lower prostate tumor protein synthesis rates. This could be a major step in understanding the link between lifestyle and cancer (progression) – Luc van Loon
Prostate cancer is the second most common cancer and the fifth leading cause of death in men worldwide. Tumour growth is influenced by several factors, including some that are triggered following food ingestion and exercise.
Eating less food (dietary energy restriction) has been proposed to slow the rate of tumour growth. Muscle mass often declines during cancer treatment and negatively impacts treatment success rates and recovery.
One important drawback is that eating less food may further decrease in skeletal muscle mass and strength in cancer patients.
However, eating less food also decreases skeletal muscle mass and strength, which would slow recovery and lower the chance of cancer treatment success.
Exercise has also been proposed to reduce tumour growth. Exercise triggers muscles to grow, which would provide further benefit to cancer patients by maintaining skeletal muscle mass, increasing mobility, and decreasing fatigue during treatment.
Currently, no study has been performed to determine whether eating less food or performing exercise directly impacts tumour and/or muscle growth responses.
Aims and objectives
This study will use a newly-available method to compare the impact of eating 30% less food versus daily exercise on muscle, prostate, and prostate tumour growth responses (i.e., protein synthesis rates) over a 7-day period prior to prostate tumour removal in prostate cancer patients.
We hypothesise that
- eating less food will lower both prostate tumour and muscle tissue growth responses and that
- daily exercise will lower the prostate tumour growth response but increase the muscle growth response in prostate cancer patients.
How it will be done
Forty-five prostate cancer patients scheduled to undergo radical prostatectomy will be randomly assigned to one of three groups.
The first group will follow their regular physical activity patterns but consume 30% less food than normal for 7 days.
The second group will follow their regular diet and physical activity patterns but perform daily exercise (1 hr of exercise plus 30 min extra walking) for 7 days.
The third group will follow their regular diet and physical activity patterns (control group).
To reduce patient burden, the entire intervention will be performed at the patients’ homes. The research team will provide all aspects of the intervention (meal plan, food items, personalized exercise supervision).
Patients will drink labelled water (2H2O) throughout the intervention period. After 7 days, patients will undergo prostate removal surgery, during which tumour tissue, skeletal muscle tissue, and blood will be collected.
Labelling of tumour and muscle tissue samples will be measured to determine tumour and muscle protein synthesis rates, which reflects growth responses in these tissues during the study.
Our findings will prove whether diet and exercise can directly impact tumour growth and muscle health in cancer patients.
We expect our findings to prove that exercise is an effective add-on therapy to enhance cancer treatment success rates by slowing tumour progression and improving/maintaining muscle mass.
As such, results from this study will aid in improving treatment outcomes, accelerating recovery, and prolonging survival in cancer patients.