**1. Introduction**

Dietary habits are an important modifiable environmental factor influencing human health and disease. Epidemiologic evidence suggests that regular consumption of fruits and vege‐ tables may reduce risk of some diseases, including cancer [1]. These properties have been attributed to foods that are rich sources of numerous bioactive compounds such as phyto‐ chemicals [2]. Modifying the intake of specific foods and/or their bioactive components seems to be a prudent, noninvasive, and cost-effective strategy for preventing some diseases in people who appear to be "healthy" [3]. As will be discussed in this chapter, potential problems occur when patients taking medicines regularly also consume certain fruits or vegetables.

Thousands of drugs are commercially available and a great percentage of the population takes at least one pharmacologically active agent on a regular basis. Given this magnitude of use and variability in individual nutritional status, dietary habits and food composition, there is a high potential for drug-nutrient interactions. However, there is a relatively short list of documented fruit-drug or vegetable-drug interactions, necessitating further and ex‐ tensive clinical evaluation. Healthcare providers, such as physicians, pharmacists, nurses, and dietitians, have to be aware of important food-drug interactions in order to optimize the therapeutic efficacy of prescribed and over-the-counter drugs. Here, we review some of the most widely consumed fruits and vegetables to inform healthcare providers of possible nu‐ trient-drug interactions and their potential clinical significance.

There are numerous patients who encounter increased risks of adverse events associated with drug-nutrient interactions. These include elderly patients, patients with cancer and/ or

properly cited.

© 2013 Rodríguez-Fragoso and Reyes-Esparza; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

malnutrition, gastrointestinal tract dysfunctions, acquired immunodeficiency syndrome and chronic diseases that require the use of multiple drugs, as well as those receiving enteral nu‐ trition or transplants. Therefore, the main reason for devoting a major review to nutrientdrug interactions is the enormous importance of fruits and vegetables used for their beneficial effects as nutrients and as components in folk medicine. There are currently few studies that combine a nutrient-based and detailed pharmacological approach [4], or studies that systematically explore the risk and benefits of fruit and vegetables [5-7].

Nutritional status and diet can affect drug action by altering metabolism and function. In addition, various dietary components can have pharmacological activity under certain cir‐ cumstances [12]. For healthy-treatment intervention, it is necessary to understand how these drug-food interactions can induce a beneficial result or lead to detrimental therapeutic con‐ ditions (less therapeutic action or more toxicity). Drug-drug interactions are widely recog‐ nized and evaluated as part of the drug-approval process, whether pharmaceutical, pharmacokinetic, or pharmacodynamic in nature. Equal attention must be paid to food-drug

Fruit/Vegetable-Drug Interactions: Effects on Drug Metabolizing Enzymes and Drug Transporters

http://dx.doi.org/10.5772/48283

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interactions (Figure 2).

**Figure 2.** Bioassay models for studying drug-phytochemical interaction.
