ABSTRACT
Antinutritional effects of polyphenolics have been demonstrated using laboratory animals (Glick and Joslyn, 1970; Myer and Gorbet, 1985; Rostagno et al., 1973) and humans (Hussein and Abbas, 1985; Stavric and Matula, 1992). These effects can be manifested as a decrease in growth rate or feed conversion (Mehansho et al., 1985; Myer and Gorbet, 1985; Rostagno et al., 1973), inhibition of enzymes (Ahmed et al., 1991; Guyot et al., 1996; Oh and Hoff, 1986), and lower egg production (Sell et al., 1983). Diets containing high levels of tannins have been reported to interfere with pancreatic digestion (Driedger and Hatfield, 1972) as well as to cause methionine deficiency by requiring active methyl groups derived from methionine in the detoxification process (Singleton and Kratzer, 1969). A number of reviews have been published on dietary intake and bioavailability of polyphenols (Bravo, 1998; Clifford, 2000; Heider and Fuchs, 1997; Heim et al., 2002; Hollman, 1997; Hollman et al., 1997; Hollman and Katan, 1997, 1999; Peterson and Dwyer, 1998; Remesy et al., 1996; Ren et al., 2001; Santos-Buelga and Scalbert, 2000; Scalbert and Williamson, 2000; Scalbert et al., 2002; Stavric and Matula, 1992; Teissedre and Landrault, 2000; Waterhouse and Walzem, 1998). Therefore, this chapter discusses only topics related to dietary intake and metabolism of polyphenols.
