Cancer Obesity

Diet and Cancer Research: What’s New?

Cancer survivors in the United States now number 15.5 million, with a 31% increase expected in the next 10 years. At one time, after completing cancer treatment, people were released without much discussion of “What now?” Today, although centers differ widely in how they handle survivorship, it represents a growing opportunity for dietitians to make a valuable difference.

Presentations at the American Institute for Cancer (AICR) Research Conference in November 2016 reflected the growth in research addressing how eating habits, physical activity, and body composition can play a role in both cancer prevention and cancer survivorship. An important area of study is how lifestyle priorities to reduce cancer risk compare with those for reducing cancer recurrence and mortality.

Overweight and obesity are now linked with greater risk of at least 11 cancers. For breast cancer survivors, the group of survivors for which we have most research, prediagnosis obesity is linked to greater mortality (both all-cause and postmenopausal breast cancer-specific). Weight gain isn’t unusual during treatment, and greater gain a year or more after treatment is linked with worse outcomes among breast cancer survivors. However, loss of lean body mass is a common problem among cancer survivors that also threatens outcomes.

At the AICR Research Conference, Italian researchers shared preliminary data from a six-month intervention trial promoting weight loss through diet, exercise, or both in overweight or obese breast cancer survivors. About one-third of participants achieved the targeted 5% weight loss. As has been shown in other populations, changes in diet led to greatest weight loss, though it was physical activity that improved lean body mass.

Prostate cancer survivors are another large target population, since men with overweight are more likely to experience cancer recurrence following prostatectomy and have a higher risk of cardiovascular disease, the primary cause of death among prostate cancer survivors. Men undergoing androgen deprivation treatment (ADT) tend to have rapid muscle loss and unhealthy body fat gain. Jill Hamilton-Reeves, PhD, RD, CSO, NSCA-CPT, shared preliminary results of a program at Kansas Medical Center that aims for weight loss before prostatectomy for men with localized prostate cancer, followed by weight maintenance after surgery. Men participating in the multipronged program with behavior coaching achieved significant weight loss and improved cardiometabolic markers, and weight was maintained 12 weeks after surgery.

A unique lifestyle intervention for cancer survivors at The Ohio State University includes experience in the onsite garden. Colleen Spees, PhD, MEd, RDN, LD, FAND, leads a team that also provides semimonthly group education, remote motivational interviewing, and behavior tracking via a secure web portal. Participants improved Healthy Eating Index scores and increased serum levels of carotenoids that are known to be markers of vegetable consumption.

At one point, cancer survivors were encouraged to establish habits of regular physical activity once cancer treatment concluded. Although certain types of cancer or treatments can place limits on forms of exercise that are safe and appropriate, evidence now shows that physical activity and dietary interventions begun before or during treatment can bring a variety of benefits. In fact, a small pilot study at The Ohio State University Comprehensive Cancer Center concluded that such an intervention in men undergoing ADT not only reduced the unhealthy changes in body composition typically seen during cancer treatment but actually reversed them.

These examples are the tip of the iceberg of all the exciting work going on across the country for cancer survivors before, during, and after treatment. Needs of individual survivors vary, but as evidence, support, and demand for survivorship programs grow, dietitians have a great career opportunity.

— Karen Collins, MS, RDN, CDN, FAND, currently serves as chair of the Sports, Cardiovascular, and Wellness Nutrition Dietetic Practice Group of the Academy of Nutrition and Dietetics. She’s also nutrition advisor to the American Institute for Cancer Research. As a consultant, Karen focuses on nutrition in the intersection of cancer prevention and heart and metabolic health. Visit Karen’s blog Smart Bytes® at http://www.karencollinsnutrition.com/smartbytes/.

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