All cells contain encoded genetic information within DNA, which determines the structure, function and behavior of these cells (1). Located in the nucleus of cells, DNA essentially dictates protein synthesis, or more specifically, which types of cells or molecules are made and when (1). The process of protein formation from DNA is complex. The two main processes are transcription and translation (1). Transcription refers to the DNA being used as a template to transfer its genetic information onto an RNA strand (1). Translation is the process by which the RNA is used to then synthesize the encoded protein (1).

Recently, there has been increasing interest in research demonstrating a connection between nutritional compounds and gene function. On March 13-14, 2003 the Division of Nutrition and Harvard Clinical Nutrition Research Center, Harvard Medical School, and the Department of Nutrition, Harvard School of Public Health sponsored the 5th Annual Symposium in Nutrition entitled, "Nutrition and Gene Regulation". The research presented on Friday, March 14, explored the potential role for several nutrients to support healthy gene function at the level of translation. Dr. Edward Giovannucci, Dr. Stephen D. Hursting, Dr. Jose A. Halperin, and Dr. John A. Milner, all top scientists, presented their latest research on the activities of folate, diet, exercise, omega-3-fatty acids, and garlic in promoting cell and gene health.

Dr. Giovannucci, chair and associate professor in the Department of Nutrition at Harvard School of Public Health, headed the presentation on folate. He discussed studies demonstrating that folate or folic acid may play a pivotal role in DNA methylation and DNA synthesis (2). Folic acid is metabolized in the body and then used to make purines and pyrimidines, key pieces that compose DNA. Folic acid can also be metabolized to 5 methyl-tetrahydrofolate (5 methyl-THF), an important molecule that is used for biological methylation reactions, including DNA methylation. (2). Dr. Giovannucci explained that folate or folic acid has been shown to directly support the level of methylation of DNA, which in turn may support the translation and expression of certain proteins involved in maintaining healthy cellular function.

Dr. Stephen D. Hursting, director of the Nutrition and Molecular Carcinogenesis Section at the National Cancer Institute, presented his latest research on the effects of diet, including calorie restriction and vegetable intake, as well as the effects of exercise on healthy cell function. One experiment involved a group of mice consuming an ad libitum diet and another group consuming a calorie-restricted diet (60% of ad libitum intake) (3,4). Calorie restriction, alone and combined with exercise, in either young or middle-aged mice was reported to provide statistically significant support for healthy cells (3,4). Most notably, Dr. Hursting reported that as the percentage of calorie restriction increased, the amount of genetic support also increased. Additionally, a freeze-dried fruit and vegetable mix was found to have a similar healthy effect as the calorie restricted diet. Moreover, data on insulin-like growth factor (IGF-1) and leptin showed a statistically significant decrease in these experimental groups. Dr. Hursting explained that this effect may contribute to the underlying support mechanism of calorie restriction, fruit and vegetable intake, and exercise. It should be noted that a decline in IGF-1 has been linked to lower bone mineralization, therefore emphasizing the importance of combining a healthy diet with exercise.

Dr. Jose A. Halperin, an associate professor of Medicine at Harvard Medical School, discussed his recent findings on the metabolism of omega-3-fatty acids, particularly eicosapentaenoic acid (EPA). His discussion described a potential nutrient-gene interaction at the level of translation. Results from an animal cell-line study revealed that EPA-exposed cells experienced statistically significant support for healthy cell function (5). Dr. Halperin postulated that EPA plays a role in a number of reactions that may ultimately maintain healthy translation initiation activity and protein function (5).

Dr. John A. Milner, Chief of the Nutritional Science Research group in the division of cancer prevention at the National Cancer Institute, has spent a large portion of his career researching bioactive food compounds, particularly those found in garlic. A recent study reported that the oil-soluble allyl sulfur compounds in garlic maintained healthy cell function and was non-tissue specific (6). One cooking tip he shared to help preserve the health promoting active compounds during cooking was to peel the fresh garlic and chop it, but then let it sit for a few minutes before adding it to the cooking food. This allows the active constituents to form and to be more efficiently utilized. Dr. Milner's interests have also included the potential for indole-3-carbinol, carotenoids, flavonoids, and selenium to support cellular health. Dr. Milner indicated that the National Cancer Institute is set to begin a large clinical trial involving 32,000 men that will investigate the effects of selenium and vitamin E on prostate health.

Additional developments will unfold as research continues exploring links between nutrients and gene expression. These types of discoveries will provide new insights on how our genes and health are impacted by diet, lifestyle and various nutrients.