![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
American Institute for Cancer Research, Washington, DC
Nearly 500 delegates attended the American Institute for Cancer Research’s 11th Annual Research Conference on Diet, Nutrition and Cancer held July 16 through July 17, 2001, in Washington, DC. The conference’s new format included split sessions geared to the diverse interests and backgrounds of attendees. In addition to many oral presentations on all aspects of the diet-cancer connection, 62 poster presentations were featured. Dr. Vay Liang W. Go of the UCLA School of Medicine was presented with this year’s AICR Research Achievement Award.
A keynote address reviewed the background of experimental and epidemiologic studies on the cancer-protective potential associated with consumption of cruciferous vegetables. This presentation discussed the growing interest in phytochemicals as anticancer agents and specifically detailed molecular mechanisms whereby sulforaphane, a compound found in many cruciferous vegetables including broccoli sprouts, seems to protect against cancer. Data were presented showing that sulforaphane can boost phase 2 detoxifying enzymes and increase antioxidant status.
There has been a striking increase in herbal use in the United States and this phenomenon has raised several pertinent issues. These issues were addressed collectively in a morning panel session at which one presenter noted that certain phytochemicals decrease the effectiveness of chemotherapeutic drugs. Another presenter detailed research exploring natural nonsteroidal anti-inflammatory compounds for possible use as cancer drugs. Because of the vast number of phytochemicals and their potential for cancer prevention, another presenter outlined a new method being used to detect and develop that potential. Data were presented on a newly uncovered anticancer agent found in garlic. An update from the National Center for Complementary and Alternative Medicine noted that an estimated 30–75% of cancer patients worldwide use complementary and alternative medicine therapies—a definition that includes dietary approaches, herbals and other biologically based treatments. Finally, an overview on herbs and plant materials used to prevent or treat cancer or as adjuncts to conventional treatment was provided. It was noted that some of the most effective modern anticancer drugs are derived from plants including products from Taxus spp.
One reason AICR recommends diets high in vegetables and fruits to reduce the risk of certain cancers is because the phytochemicals found in these foods seem to modulate gene expression in various protective ways. A panel session on the molecular mechanisms of cancer-preventive agents presented data from several cellular systems. These systems are used by researchers to track the ability of specific dietary components to regulate specific genes. Genes regulated by retinoic acid (vitamin A), for example, have been identified. Dietary fiber gives rise to short-chain fatty acids (SCFA), which alter the expression of genes associated with human colorectal cancer. The phytoalexin trans-resveratrol appears to block the initiation of inflammation and the cancer process itself. Certain nuclear receptors can bind to dietary flavonoids (like those found in black and green teas), which may alter certain biochemical pathways in protective ways. Data indicating that restricting specific amino acids can regulate gene expression suggest a possible means to inhibit the growth of tumors.
One recommendation that arose throughout this conference was to place the emphasis on dietary patterns or whole diets rather than on individual dietary components. A panel addressed itself to the notion of whole diets from several different perspectives. One presentation pointed out that many phytochemicals are distinctly colorful, thus providing an easy way to communicate increased diversity of fruits and vegetables to the public and ensure that a wide variety is ingested daily. A presentation on the macrobiotic diet suggested that such diets may provide an alternative or complementary lifestyle approach to cancer treatment but stressed that further research is needed. Collective data have provided evidence that the diet of Greece may be particularly effective in decreasing the risk of certain types of cancer; again the emphasis is on the whole dietary pattern. Another presentation proposed that food combinations can lessen cancer risk. It was pointed out that there must be effective communication to the public of dietary recommendations that are based on sound science.
A second molecular biology session on emerging genetic models to study cancer was largely devoted to the use of data from transgenic rodent models. These models aid scientists in understanding the possible role of nutrient-gene interactions in cancer prevention and treatment. The potential of environmental chemicals and food contaminants to trigger the kind of damage that leads to cancer may be modified by other dietary components. One model presented here included green tea components and conjugated linoleic acid. Several presentations at this conference discussed the concept that energy restriction (low calorie diets) can inhibit tumorigenesis. In one case, energy restriction was shown to inhibit estrogen-induced mammary carcinogenesis in an ACI rat model, thus demonstrating a hormone-diet interaction. Energy restriction also delays the development of spontaneous tumors in genetically modified mice. It was noted that intervention trials for cancer prevention using antioxidant supplements have produced mixed results. A beneficial role for SCFA has emerged from some studies of dietary and genetic interactions in intestinal cancer in transgenic mice.
AICR is increasingly concerned with nutritional support for cancer patients and survivors. Because of the growing number of cancer survivors in the United States, demand is increasing for dietary advice geared to their specific circumstances. The first AICR-sponsored conference on the role of diet in cancer survivorship was held in May 2001, and an entire session of the 11th Annual AICR Research Conference was devoted to the survivorship issue. Presenters and attendees discussed the major questions facing scientists, i.e., whether specific diets can improve survival and whether dietary strategies can diminish the side effects of therapy. Factors, including intake of red meat, calcium, vitamin D and fiber, are being assessed with regard to colon cancer survival. Possible nutritional supplements and alternative medications for prostate cancer survivors were also discussed. A major topic of current interest is whether cancer survivors should consume large amounts of soy; the conclusion was that additional data are required before this issue can be resolved.
The first preliminary data were presented from the European Prospective Investigation into Cancer and Nutrition, the largest study to date on the diet-cancer link. The study is supported by the Europe Against Cancer Program and involves over a half-million subjects in 10 European countries. Another presentation described the relationships among energy balance, insulin, insulin-like growth factor and colon cancer; one interaction recently noted is that the physical activity of the subjects was inversely related to colon cancer risk. Physical activity and body mass index were referred to in other presentations on cancer risk factors. Two presentations had as their focus the progress made on the National Cancer Institute’s 5 A Day program to increase fruit and vegetable consumption. The encouraging news is that there is increased consumption of fruits and vegetables and a greater awareness of the effort. It has been recommended that the National Cancer Institute continue to support and coordinate the program.
The challenge of translating dietary recommendations into effective interventions has begun. In his closing remarks, Dr. Vay Liang W. Go pointed out that 20–30 y ago the emphasis was on cancer treatment; today the spotlight has shifted to cancer prevention. This shift was spurred in part by the knowledge that many phases of the cancer process are influenced by nutrition. A plant-based diet with increased consumption of fruits and vegetables and increased physical fitness is recommended. At a luncheon presentation, AICR outlined the New American Plate, the Institute’s highly successful educational program that synthesizes the latest science on diet and cancer and communicates it to the public in a clear and colorful way.
Since its founding in 1982, AICR has devoted itself exclusively to the link between diet and cancer. It is the third largest cancer charity in the United States. The institute provides a wide range of education programs to help people make changes for lower cancer risk in addition to supporting innovative research in cancer prevention and treatment at universities, hospitals and research centers throughout the United States.
 |
FOOTNOTES |
|---|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
