The American Cancer Society recently released a revision to their nutrition and physical activity guidelines for cancer survivors. The guidelines were compiled by an expert panel that reviewed the wealth of new evidence that has been published since the original guidelines were released in 2006. While many of the guidelines are similar to those for cancer prevention, the proliferation of high quality science in the subsequent years has led to some key refinements in the messages.
Here are a few highlights:
- When it comes to question of nutrition and physical activity, “survivors soon find there are few clear answers to even the simplest questions.” What the evidence base shows is that the answers on what foods or what exercise will likely vary , in some regards, from one cancer to another (remember, we say “cancer,” but we’re talking about dozens of diseases) and based on treatment type as well as numerous other individual level factors. Despite this and that more research needs to be done to fill in the gaps (e.g., more than 80% of the intervention evidence for the safety and efficacy of exercise in survivors comes from breast cancer populations), recommendations on exercise and diet can and have been made.
- The ACS guidelines are for primarily targeted to health care providers. (Exercise professionals looking for field specific guidance can turn to the ACSM guidelines.) Why target providers? “Physicians and other health care providers have a unique opportunity to guide cancer patients toward optimal lifestyle choices, and thus can favorably influence the survivorship trajectory regardless of the individual’s survivorship phase. The power of physician advice in facilitating preventive health behaviors has been consistently demonstrated.” Patients look to providers for information. Unfortunately, physicians aren’t always well informed about the evidence for the importance of lifestyle. (Many are, but it is more common for me to meet an oncologist surprised at the depth of evidence for the benefits of exercise among survivors than to meet one who is well versed in it.) These guidelines are an important part of that education and outreach process. Physicians need not do all the counseling themselves, but do need to provide referrals to the appropriate followup lifestyle care such as with a certified fitness professional or nutritionist.
-Addressed with new gusto in the ACS guidelines is supplement use, with good reason. “A recent systematic review indicates that 14% to 32% of cancer survivors initiate supplement use after their diagnosis. Breast cancer survivors report the highest prevalence of supplement use, whereas prostate cancer survivors report the lowest.” Despite the high prevalence of use, the guidelines note, “dietary supplements are unlikely to improve prognosis or overall survival after the diagnosis of cancer, and may actually increase mortality.” The appeal of supplements is logical – people often feel they are struggling to get adequate nutrients through foods, and a whole industry exists to play to that concern. But the guidelines are clear: “Before supplements are prescribed or taken, all attempts should be made to obtain needed nutrients through dietary sources. Supplements should be considered only if a nutrient deficiency is either biochemically (eg, low plasma vitamin D levels, B12 deficiency) or clinically (eg, low bone density) demonstrated. Supplements should be considered if nutrient intakes fall persistently below two-thirds of the recommended intake levels. Such a determination should be made by a registered dietitian.”
The supplements provide a nice example of why patient provider communication is key to healthy survivorship. If providers don’t know what patients are doing, eating, taking, they can’t provide the recommendations of what to continue and what to change. As the guidelines note, “Open dialogue between patients and health care providers should occur regarding dietary supplementation to ensure there is no contraindication in relation to the prescribed cancer therapy or for longer term health effects.” In fact, open dialog is important for making any lifestyle change!