Nutrigenomics is a branch of nutritional genomics and is the study of the effects of foods and food constituents on gene expression. This means that nutrigenomics is research focusing on identifying and understanding molecular-level interaction between nutrients and other dietary bio-actives with the genome.
Nutrigenomics has received much attention recently because of its potential for preventing, mitigating, or treating chronic disease, and certain cancers, through small but highly informative dietary changes. The conceptual basis for this new branch of genomic research can best be summarized by the following five tenets of nutrigenomics:
- Under certain circumstances and in some individuals, diet can be a serious risk factor for a number of diseases.
- Common dietary chemicals can act on the human genome, either directly or indirectly, to alter gene expression or structure.
- The degree to which diet influences the balance between healthy and disease states may depend on an individual’s genetic makeup.
- Some diet-regulated genes (and their normal, common variants) are likely to play a role in the onset, incidence, progression, and/or severity of chronic diseases.
- Dietary intervention based on knowledge of nutritional requirement, nutritional status, and genotype (i.e., “personalized nutrition”) can be used to prevent, mitigate or cure chronic disease.
The promise of nutritional genomics is personalized medicine and health based upon an understanding of our nutritional needs, nutritional and health status, and our genotype. Nutrigenomics will also have impacts on society from medicine to agricultural and dietary practices to social and public policies and its applications are likely to exceed that of even the human genome project. Chronic diseases (and some types of cancer) may be preventable, or at least delayed, by balanced, sensible diets.
Nutrigenomics and the Prevention & Management of Cancer
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 researchers 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.