News from the Field
Plenty of Food for Thought Served Up at the Nutrition and Cancer Prevention Research Practicum
From March 12-16, 2012 a select group of participants attended the Nutrition and Cancer Prevention Research Practicum hosted by the Nutritional Science Research Group (NSRG) within the Division of Cancer Prevention. The practicum began nine years ago with sixteen dietetic interns and gradually grew as others expressed interest in attending. This year’s participants included graduate students, dietetic interns, Registered Dietitians, postdoctoral research fellows, physicians, and a Registered Nurse. “Interest in this practicum has expanded beyond NIH. Participants have come from all over the country, and in recent years, we’ve had a number of international attendees from countries including Brazil, Italy, Ireland, and Mexico,” noted Elaine Trujillo, M.S., RD, CSND, a nutritionist with NSRG who organized the practicum.
The practicum offered an intense week of learning about the latest research in nutrition science and cancer. According to Dr. John Milner, Chief of the NSRG, the goal of the practicum was “to promote a greater understanding of the complex relationship between diet and cancer prevention and to encourage individuals to actively participate in research that will help provide clarification about the specific role of foods and food components as modifiers of cancer risk and tumor behavior.”
The week’s speakers included researchers from NSRG, NIH Program Officers, and representatives from advocacy groups. Many of the lectures dealt with specific foods, their effects on cancer, and their role in cancer prevention. Participants got a good overview of the latest research on potential anti-cancer effects of tomatoes, soy, cruciferous vegetables, and green tea, among other topics. Gabriela Riscuta, M.D., CNS (from NSRG) spoke about health benefits of mushrooms, focusing on ß-glucans that are found in mushroom cell walls. She also described two epidemiological studies that showed consumption of mushrooms may lower the risk of developing breast cancer. The attendees also gained a sense from the presentations of how to interpret the findings, which were often inconclusive.
Some common themes apparent in the lectures, besides the enthusiasm of all of the speakers, were that methods of preparation (such as cooking food versus eating raw food) may affect activity of nutritional components and that bioactive food components will affect individuals to varying degrees. For example, researchers are increasingly looking at how individual genetics affect responses to bioactive food components and why some people may have a greater response than others to those components. Brooke Savage, a graduate student at the University of Massachusetts, Amherst, was impressed by the lectures. “It’s great to see my education come together and how it applies to real-world situations,” she said.
There were a number of lectures that stepped out of the lab and focused on various topics of interest to the attendees. For instance, speakers presented information about numerous resources (such as databases and websites) available for researchers and clinicians. There were also talks about obtaining grant funding from the NIH, which featured discussions of different award mechanisms available, and ways to communicate research findings to patients and the public.
The practicum was not just a week of lectures and classroom-based learning. The week’s events also included a trip to Beltsville, Maryland and a Nutrition Research Day at the Clinical Center on NIH’s Main Campus. In Beltsville, the attendees took a tour of the U.S. Department of Agriculture (USDA) Human Nutrition Research Center. During the tour, they learned about the different types of clinical studies conducted there on human volunteers. Darci Barman, a graduate student at Bastyr University, commented, “I am interested in human nutrition research, so it was a good experience seeing some of the labs — especially the calorimetry rooms — at the Nutrition Research Center.” As part of Nutrition Research Day, the attendees heard about clinical research studies conducted at NIH and took a tour of the Clinical Center. “I’ve never been to NIH before, so it was interesting to see how everything runs. Taking a tour of the Clinical Center was helpful in clarifying NIH’s role in patient care and clinical trials,” noted Shaekira Collins, a graduate student at Bastyr University.
Tiffany Barrett, a Registered Dietitian at the Winship Cancer Institute at Emory University Hospital, said that one of the best things about the practicum was “making research more practical for patients.” She added, “Anything I can bring back to my patients, not just for one-on-one discussions but also for presentations, is very helpful.” The practicum did not exactly provide participants with a checklist of foods they should add to their diet to reduce their risk of developing cancer. It raised more questions than it answered, hopefully providing potential research ideas — and lots of food for thought — for the attendees.
Visit the Nutritional Science Research Group’s website, http://prevention.cancer.gov/nutrition, for information about next year’s practicum and how to apply.
The Jury Is Still Out on Antioxidant Use Alongside Conventional Cancer Treatments
Antioxidants help prevent the damage that can occur to cell membranes and DNA by highly chemically active molecules called free radicals. Many cancer patients take antioxidants while undergoing conventional treatment, although it is unknown how helpful — or harmful — those supplements may be. On the one hand, antioxidants may help protect healthy (non-cancerous) cells from damage caused by chemotherapy or radiation. On the other hand, antioxidants may also be protecting the cancer cells targeted by those treatments. Published studies support both sides of the argument. A new review article*, authored by OCCAM Director Dr. Jeffrey D. White, former OCCAM contractor Akiko Nakayama, and interns Karen P. Alladin and Obianuju Igbokwe, evaluated studies that investigated the effects of antioxidants administered alongside chemotherapy or radiation.
Among the studies reviewed, the majority used the antioxidants glutathione (GSH), different types of vitamin E, or N-acetylcysteine (NAC). Analysis of the studies revealed a number of deficiencies. For example, many studies did not disclose product details (such as manufacturer information) or why a specific dose of antioxidant was used. The primary end points of the studies also differed: some measured the response of the tumor to the treatments while others assessed symptom/side effect management. There were also numerous combinations of antioxidant, chemotherapy, and radiation treatments used in the studies. According to the authors of the review, “Among the 52 clinical trials we reviewed, only five studies of glutathione and two studies of NAC used exactly the same antioxidant and conventional cancer therapy doses and regimens in the same cancer types.” The variations in study design and absence of important information make it difficult to reach a consensus about how useful antioxidants are when taken alongside chemotherapy or radiation. The authors concluded their review by providing suggestions for establishing evidence-based clinical guidelines for antioxidant use during cancer treatment. They noted that more research is needed identifying mechanisms of actions of antioxidants and the optimal doses and formulations required for patients.
The authors point to an example from colorectal cancer, combining folinic acid with fluorouracil (5-FU). Many studies have investigated this combination and the mechanism through which folinic acid affects 5-FU is now well known.
To read more, go to http://www.ncbi.nlm. nih.gov/pubmed/22085269.
* Nakayama A., Alladin K.P., Igbokwe O., White J.D. (2011). Systematic review: generating evidence-based guidelines on the concurrent use of dietary antioxidants
and chemotherapy or radiotherapy. Cancer Investigation, 29(10):655-67.