Chapter 1 Functional Food and Health: An Overview Downloaded via 148.251.232.83 on October 7, 2018 at 18:47:09 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles. Takayuki Shibamoto 1, Kazuki Kanazawa 2, Fereidoon Shahidi 3, and Chi-Tang Ho 4 1 Department of Environmental Toxicity, University of California, Davis, CA 95616 2 Laboratory of Food and Nutritional Chemistry, Faculty of Agriculture, Kobe University, Rokkodai, Nada-ku, Kobe 657-8501, Japan 3 Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada department of Food Science, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903 Functional food ingredients and nutraceutical products are important in health promotion and disease risk reduction. Such foods are expected to render physiological benefits beyond their traditional nutritional value. Although presence of phytochemicals and bioactives in foods is important, their absorption, bioavailability and metabolism are also critical factors that influence in their beneficial effects. Processing, however, may affect such bioactives and hence process induced changes in functional food ingredients must be carefully examined. Furthermore, the mechanisms of action of bioactivies in food are numerous, but include antioxidant activity, among others. Important aspects of functional foods and their health benefits are presented. 2008 American Chemical Society 1
2 It has been over 20 years since the concept of "Functional Foods" was first introduced as a third factor in the analysis of foods after nutrients, such as proteins, lipids, and carbohydrate, andflavors,such as sugars, acids, and volatile compounds. Not only food chemists but also many scientists from diverse areas, including biology, biochemistry, botany, plant/animal sciences, and nutrition as well as medical science, have become involved in research associated with functional foods today. Moreover, consumers are now deeply interested in the food factors which provide beneficial effects to humans in terms of health promotion and disease risk reduction. They also demand more detailed information about food factors in order to obtain appropriate functional food products. This Proceeding book comprises six major subject areas: 1. Overview and Perspectives (4 chapters), 2. Bioavailability and Metabolism (5 chapters), 3. Cereals (3 chapters), 4. Antioxidants (12 chapters), 5. Carcinogenesis and Anticarcinogenesis (6 chapters), and 6. Other Health Effects (10 chapters). Overview and Perspectives The concept of functional foods is relatively new to the United States compared to the countries of Asia. Some foodstuffs, such as herbs and spices, have been used as folk medicine. However, since the modern concept of functional foods was advanced nearly 20 years ago, there have been numerous studies and symposiums focused on functional foods or food factors in all parts of the world (1-5). In order to satisfy the consumers' interest in the relationship between foods and health benefits as well as the growing interest in the up-todate research on functional foods among researchers in various fields, many excellent overview articles on and articles offering different perspectives on functional foods have been published. The Overview and Perspectives section covers the bioavailability of dietary phytochemicals, such as flavonoids. A single cell gel electrophoresis assay to determine DNA migration associated with DNA damage is introduced. An overview of the biological and pharmacological effects of flavonoids is outlined. The current development of the guidelines of good agricultural practices related to herbal medicines is summarized. Bioavailability and Metabolism A tremendous number of food components with medicinal activities beside nutrients, such as proteins, lipids, and carbohydrates, have been found in various natural plants. These so-called phytochemicals include terpenoids, xanthophylls,
phenolic compounds, and some sulfur-containing compounds (4). Also, many studies on the metabolic pathways of functional phytochemicals, such as flavonoids, have been reported (5). The Bioavailability and Metabolism section contains research results from the bioavailability and metabolic fates of various naturally occurring chemicals, including anthocyanins, phenolic acids, and flavonoids soybean isoflavones, including daidzein, and quercetin. The general metabolic pathway of anthocyanins in rats was found to occur at the O-methylation of the B ring and glucuronidation of both anthocyanidin and anthocyanin. The effect of phenolic acid, gallic acid, on the expression of the phase II P-form of phenol sulfotransferase in human hepatoma HepG2 cells is described. The role of the acylated moiety in in vivo uptake and in the antioxidant activity of anthocyanins is reported. Quercetin was found to prevent the early stage of carcinogenesis in a study using male F344 rats. 3 Cereal Cereals or grains are the most important source of nutrients, such as protein and carbohydrates, for people throughout the entire world, and particularly in the developing countries (6). It is known that cereals contain various health beneficial compounds such as phytoestrogens and phenolics (7). Cereal and grains are one of the most important food sources. In particular, wheat is consumed by people in almost all countries. Its world production reached over 600 tons in 2005. It is rich in carbohydrate and proteins. Recently, the presence of health beneficial phenolic compounds in cereal has been recognized. In the Cereal section, wheat grain is evaluated for its antioxidant, anti-proliferation, cyclooxygenase-2-inhibition, and phytochemical properties. A comprehensive summary of phenolic compounds, such as caffeic acid and ferulic acid, found in grains and their antioxidant activities is presented. Antioxidants Research related to antioxidants represents nearly 70% of the studies focused on functional foods today. Most of these studies involve natural products, such as fruits, vegetables, whole grains, herbs, and leaves as well as some seafood. The classic concept of antioxidants present in foods is that of vitamins (A, C, and E) and minerals. Later, potent antioxidant activity was discovered in various naturally occurring chemicals in foodstuffs. Examples are carotenoids (source of vitamin A), polyphenols, flavonoids, anthocyanins, and lycopene (2,3). In addition, most recently, some aroma and flavor chemicals,
4 such as certain terpenes (8) and volatile heterocyclic compounds (9), have been found to possess appreciable antioxidant activity. Consumption of antioxidants has been recommended to protect oxidative damage, which promotes various diseases including cancer, cardiovascular disease, cognitive impairment, Alzheimer's disease, immune dysfunction, cataract, and various inflammatory diseases (10). The Antioxidant section is one of the core parts of this proceedings. The results of antioxidant studies on many naturally occurring chemicals in various plant foodstuffs are reported. The antioxidants present were turmerone, curlone, and ct-terpineol in curcumin-free turmeric oil; caffeic acid in parsley; ferulic acid, methyl ferulate, isoferulic acid, sinapic acid, and methyl sinapate in radish sprout; volatile chemicals in herbs, spices, and teas; proanthocyanidins in grape, pine, and witch hazel; flavonoids in young green barley leaves and agrofood byproducts; and polyphenols in citrus. Antioxidant activities of various terpenoids, coumarins, and flavonoids from Mexican and Chilean plants, such as Meliaceae and Zygophyllaceae families, were also reported. The role of various polyphenol antioxidants, such as tannins, catechin, chlorogenic acid, and gallic acid, in the inhibition of aflatoxin biosynthesis is presented here for the first time. In addition to these chemicals, some polymers, such as phosphopeptides from hen egg yolk, were discovered to suppress oxidative stress-induced gut inflammatory disorders. Carcinogenesis and Anti-carcinogenesis One of people's major concerns is how to prevent cancer incidences because cancer has been ranked among the top three causes of death in developing countries. Therefore, consumption of certain anti-cancer chemicals present in foods and beverages has begun to receive much attention as a promising strategy to prevent cancer (11). The section on Carcinogenesis and Anti-carcinogenesis reports studies performed using biological systems. Chemopreventive effects of natural anthocyanins were investigated using animal and human cells. A study on cancer preventive mechanisms was conducted using epigallocatechin 3-gallate. Human leukemia cancer cells were used to examine the growth inhibitory effects of black tea polyphenol, theaflavin. A significant relationship between 8- hydroxydeoxyguanosine formation and oxidized dietary oils in feed was found using mice. The suppressant effects of flavonoids on AhR transformation induced by dioxin were observed in a system consisting of rat hepatic cytosol fraction.
5 Other Health Effects Comprehensive epidemiological studies indicate that cancer risk in people consuming diets high in fruits and vegetables is much lower than in those consuming few of these foods (12). However, the effects of phytochemicals present in foods, including fruits and vegetables, not only preventing cancer but also preventing various other diseases. Therefore, there have been many reports on food factors associated with diseases beside cancer. In addition to the topics presented in the above five sections, miscellaneous studies on food factors have also been reported. Many health beneficial activities of a variety of food components were demonstrated: the antimicrobial activity of the pungent components of wasabi isothiocyanates against periodontal pathogens, immunomodulatory activities of (3-glucan found in mushroom, antidepressant effects of Ginkgo biloba, Serum cholesterol-lowering effects of a broccoli and cabbage juice mixture, inhibition of angiotensin converting enzyme (ACE) by Tahitian Noni juice, and inhibitory activities of vialinins A and B against TNF-αproduction. The topics introduced in this book are all original studies, were prepared and presented by experts in the area of functional foods. Therefore, this proceeding book provides up-to-date research results and a cutting-edge review of the status of functional food research in various countries. References 1. Ohigashi, H.; Osawa, T.; Terao, J.; Watanabe, S.; Yoshikawa, T. (Eds.) Food Factors for Cancer Prevention. Springer-Verlag Tokyo: Tokyo, Japan, 1997. 2. Shibamoto, T.; Terao, J.; Osawa, T. (Eds). Functional Foods for Disease Prevention I: Fruits, Vegetables, and Teas, and II: Medicinal Plants and Other Foods. ACS Symposium Series 701, ACS: Washington, DC, 1998. 3. Shahidi, F.; Ho, C.T. (Eds.) Antioxidant Measurement and Applications. ACS Symposium Series 956, ACS: Washington, DC, 2007. 4. Sakakibara, H.; Honda, Y.; Nakagawa, S.; Ashida, H.; Kanazawa, K. J. Agric. FoodChem. 2003, 57, 571-581. 5. van der Woude, H.; Boersma, M. G.; Vervoort, J.; Rietjens, I. M. Chem. Res. Toxicol. 2004, 17, 1520-1530. 6. Pedersen, B.; Knudsen, K.E.; Eggum, B.O. World Rev. Nutr. Diet 1989, 60, 1-91.
6 7. Slavin, J.L.; Jacobs, D.; Marquart, L.; Wiemer, K. J. Am. Diet. Assoc. 2001, 101, 780-785. 8. Lee, K.-G.; Shibamoto, T. J. Agric. Food Chem. 2002, 50, 4947-4952. 9. Yanagimoto, K.; Lee, K.-G.; Ochi, H.; Shibamoto, T. J. Agric. Food Chem. 2002, 50, 5480-5484. 10. Hasler, C. M. Functional Foods: Their Role in Disease Prevention and Health Promotion. http://www.nutriwatch.org/04foods/ff.html (accessed on August 30, 2006). 11. Surh, Y. J. Nat. Rev. Cancer 2003, 3, 768-780. 12. Block, G.; Patterson, B.; Subar, A. Nutr. Cancer 1992, 18, 1-29.