Science behind the TrueNTH Exercise and Diet Project
Significant work has been undertaken in the last 5 years in improving cancer survival. The UK National Cancer Survivorship Initiative recovery package aims to help people affected by cancer to prepare for the future and return to a lifestyle as near to normal as possible. Lifestyle management has also been developed for chronic illness in primary care, and health and well-being clinics are currently being set-up as part of this initiative.
Our research therefore offers an opportunity to influence and complement what is currently provided. Good quality evidence exists that physical activity can reduce functional problems after cancer treatment and improve fitness. While several systematic reviews have shown that exercise can have small to moderate benefits in reducing symptoms during treatment, there is evidence to suggest that it can exert a much greater impact after cancer therapy.
Despite these developments, clinical teams and men are not yet using these initiatives. Part of the reason may be that men themselves are unaware of the risks, but it may also be that clinical teams focus on the disease and treatment and have little time or capacity to endorse lifestyle interventions for men after treatment.
So what’s the evidence that exercise and lifestyle can impact on men with prostate cancer?
Evidence comes from several sources. A study conducted in the USA where researchers followed 2705 men diagnosed with prostate cancer over 10 years, and monitored their activity levels. The research showed that the number of deaths in total was lower for 1 in 3 men who walked on average an hour per day (moderate activity). Outcomes were that prostate cancer recurrence was lower for half of the men taking three or more hours of vigorous activity each week and even fewer men were dying from diseases including cardiovascular events.
Research is starting to explore why exercise might be protective, it may alter the distribution and metabolic properties of body fat and in this way impact on energy balance. Firstly, obesity is strongly associated with higher risk of prostate cancer occurrence. Trials are just beginning to evaluate the health benefits of weight loss after treatment but since these are almost exclusively in women with breast cancer, we need to know more about diet interventions for men and how this impacts on survival.
At present we are aware of the risks of heart attacks, diabetes and strokes for men receiving ADT for palliative disease with the risk being at its highest in the first year of treatment (men have a 12 times higher risk than men without prostate cancer) but there is unclear evidence as to the risk for those men who receive ADT for only a few months or already have existing risks such as obesity or have smoked.
Exercise has been shown to be able to reverse side effects in controlled pilot studies but we need bigger population studies to see if this intervention can be adopted in the wider community and influence risk. We need to know more about how we target advice and how clinical assessments can provide individualised exercise and diet but also how effective this is in improving health.