By: Peiying Yang, Ph.D., Stephanie Maxson, MS, RD, LD, and Lorenzo Cohen, Ph.D., Integrative Medicine Program, MD Anderson Cancer Center
Diet plays an important role in cancer prevention and control. Though the association between diet and cancer prevention is still not definitive, recent evidence suggests that diet may modify the risk and improve outcomes of many cancers, including gastric, colorectal, breast, prostate, and lung cancers. Nutrition recommendations are typically based on the assumption that all individuals have the same nutritional requirements, with the exception of small differences between life stages and genders. However, recent advances in genetic sciences reveal that because each individual is genetically unique, not everyone responds identically to specific nutrients. Nutrigenomics, a relatively new science, explores the role of vitamins, minerals, and bioactive food compounds in gene expression and the effect that individual genetic variation can have on the body's response to specific foods.
Compelling evidence suggests nutrients from food likely influence human health through the foods' ability to alter genetic and epigenetic (changes in gene expression caused by mechanisms other than changes in the DNA sequence) events associated with various diseases including cancer. Scientists are working hard to uncover gene-nutrient associations for all types of diseases, especially cancer. Once these associations are better understood, nutrition recommendations can be then personalized for disease prevention and management.
For example, research has shown a link between inadequate folate (one of the essential B vitamins) intake and increased risk of colorectal cancer. However, the response to folate deficiency appears to vary between individuals depending on their genetics. Similarly, the increased risk of colorectal cancer with red meat consumption also seems to vary from one person to another depending on genetic variations associated with metabolism. Therefore, the amount of folate or red meat necessary to influence colorectal cancer risk will vary from one person to another depending on their genes.
Additionally, studies have suggested higher intake of cruciferous vegetables is associated with reduced risk of colorectal and lung cancer. This occurs mainly among patients with lower expression of enzymes responsible for secretion of sulforaphane, a key bioactive compound in cruciferous vegetables. These examples of gene-nutrient associations in cancer are a few of many that we are just beginning to understand. Therefore, a person's response to a particular nutrient likely depends on their genetics.
Although nutrigenomics is a science still in its infancy, there is tremendous potential for the application of nutrition in cancer prevention and management. As this field advances, the future of nutritional care will be personalized diet recommendations based on an individual's genetic profile and physiologic needs.
Until we have enough evidence to practice individualized nutrition, everyone should follow these basic recommendations:
• Fill the majority of your plate with plant foods, including a wide variety of plants in all colors of the rainbow.
• Aim to get your nutrients from whole foods (defined as unprocessed foods, such as broccoli, lentils or brown rice) rather than supplements to increase variety of nutrients consumed.
• Avoid excessively high intake of any one nutrient.
• If you have had cancer or have a family history of cancer, it would be prudent to follow the American Cancer Society's diet recommendations for reducing cancer risk. A dietitian or health care practitioner can offer specific recommendations based on the particular cancer of concern.
For more information on diet and other lifestyle factors for cancer prevention and control, join Dr. Lorenzo Cohen and Alison Jefferies November 21, 2013, 7-8:30 PM, St. Catherine's Montessori, 9821 Timberside, Houston, TX to learn more about Living the Anticancer LifeTM and how to put it all into practice both as an individual and within a family.
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