Dictionary of Nutraceuticals and Functional Foods by N.A. Michael Eskin and Snait Tamir. Boca Raton, FL: Taylor & Francis Group/CRC Press; 2006. Hardcover; 507 pages. ISBN-13: 978-0849-3157-25. $89.95.
Except to take advantage of the current popularity of the term “nutraceuticals,” I found no defensible reason why this text was allowed to go into print. Firstly, it is not a dictionary. As the authors admit, both of whom are biochemists with backgrounds in food sciences, it is more of a “mini-encyclopedia.” If it were a dictionary, I would expect it to provide pronunciations of the terms it attempts to describe, as limited in number as they are (480 functional foods and nutraceuticals). Yet even a mini-encyclopedia would be expected to consistently provide Latin binomials for the plants it covers and to provide a basic description of the plant, which it does not, except in rare instances (e.g., blackberry). Instead, only some of the plant entries have binomials, some have both binomials and botanical authorities, and for some, the plant family is given. For whatever reason, items such as apples, caraway, coffee, milk thistle, saw palmetto berries, pears, pinto beans, and sweet potatoes, to name but a few, are not accorded their Latin names. Other common items, on the other hand, are provided such identification: apricot (Prunus armeniaca, Rosaceae), blackberry (Rubus corchorifolius, Rosaceae), carrot (Daucus carota, noted in this book as being in the “Umbelliferae family” instead of the commonly accepted Apiaceae), coriander (Coriandrum sativum, Apiaceae), oregano (Origanum vulgare, identified as being in the “Labiatae family,” instead of Lamiaceae), and paprika (Capsicum annuum, Solanaceae). For angelica, as in many other entries, the Latin names do not follow the common name but are instead found later in the text; in this case only the species Angelica furcijuga (Apiaceae) and Angelica japonica are named, without authorities or families. The opposite is also found and with surprising frequency. For Morinda citrifolia (misspelled as citrifola in the text) (Rubiaceae), for example, the common names provided, “Indian mulberry” and “Mengkudu,” fail to include noni, the more widely known common name. And whereas Echinacea purpurea (Asteraceae) is discussed, no other species of the genus are even mentioned.
The term “nutraceutical” is described in the preface as “bioactive components responsible for the health benefits of functional foods”; the latter being “similar in appearance to conventional foods, but in addition to providing basic nutritional components, have physiological benefits that can reduce the risk of chronic diseases.” The subject of toxicity is largely avoided. Under ethanol and foxglove (Digitalis purpurea, Scrophulariaceae), however, associated harm is discussed, as one would hope. Still, I have to wonder why they were included at the obvious expense of other nutraceuticals or functional foods, particularly since foxglove—or any species in the genus Digitalis—is never sold as a functional food or nutraceutical in any culture or country with which I am familiar! From the examples covered, nutraceuticals apparently include any natural product known to humankind, from the potentially or definitely poisonous to the benign. For example, among the diverse items listed, the authors include sweet flag (Acorus calamus, Acoraceae) and rosy periwinkle (Catharanthus roseus, Apocynaceae), but without any mention of their functions as foods (some types of calamus root, such as sweet flag, are edible, but periwinkle?) or their risk of producing toxicity.
Throughout the text, an inordinate amount of attention is given to the in vitro cytotoxic effects of natural products against tumor cells. The authors list highly cytotoxic compounds found in various marine sponges, and without naming the species, a “cytotoxic compound” (“thyrsiferyl 23-acetate”) isolated from “marine red alga.” Substances such as those are certainly of interest to chemists developing new anticancer drugs, but to classify them as functional foods or nutraceuticals is quite a stretch.
The profusion of illustrations, tables, and charts accompanying the text, usually taken from a single study, give little perspective of the subject being described and often occupy over half a page. These, too, are at the expense of entries that one would anticipate in a text with such an encompassing title. And if you thought that substances with attending human clinical trials would take precedence over obscure, scarcely studied ones, you would be sadly disappointed. Even in cases where such nutraceuticals are listed, clinical trials receive scant citation or are entirely ignored.
Although I do not mean to imply that most of the text is incorrect or uninteresting, it does have its share of bewildering, obviously unedited statements. For example, mangiferin from Mangifera indica (Anacardiaceae) is stated to be “a constituent of folk medicines,” regardless of its occurrence in diverse plants, medicinal and otherwise. The text mentions esculetin but misspells the word as “esculentin” and refers to it as a coumarin derivative rather than correctly as a peptide, stating that it “has been used for centuries in China as folk medicine.” Elsewhere in the text, one reads that, “In Latin America, the flowers, leaves, and vine tips of Cucurbita spp. are widely consumed, because they exhibit a wide range of biological activities in plants and animals.” Further, the authors state that “Uva ursi (Arctostaphylos uva-ursi) is a compound extracted from the bearberry plant,” incorrectly identifying uva ursi as a compound rather than the common name of a plant. It is also written that “Glucoraphanin, the natural precursor of sulforaphane found mostly in cruciferous vegetables, but also in radishes, is known for maintaining good heath.” Apart from the obvious misspelling of “health,” the text fails to disclose any of the circumstances under which glucoraphanin maintains health.
A handful of traditional Chinese herbal medicines are discussed: Job’s tears (Coix lacryma-jobi, Poaceae), bitter tea (Ligustrum pedunculare, Apiaceae), Chinese bellflower (Platycodon grandiflorum, Campanulaceae), peony (Paeoniae spp., Paeoniaceae), Rehmannia (Rehmannia glutinosa, Scrophulariaceae), and dandelion (Taraxacum officinale, Asteraceae). Their Chinese common names are absent and the brief reviews are highly inadequate. As in most of the entries throughout the text, the authors focus on the details of a few activity studies to the exclusion of others of equal or greater importance. I can only suppose that for some it would be enough to know that Sho-saiko-to (the well-researched Japanese Kampo formulation known in Chinese traditional medicine as minor Bupleurum formula) is “a mixture drug of medicinal herbs prepared from the hot-water extraction of seven raw materials,” even though what those materials are is not something the authors deemed worthy of inclusion.
It would also be useful to know that the carotenoids lutein and zeaxanthin are commercially obtained from marigold flowers (Tagetes erecta, Asteraceae). Instead, the authors list only some of their more common food sources, and Tagetes is nowhere to be found. Among other omissions, I could find oyster mushroom (Pleurotus ostreatus, Tricholomataceae) and ganoderma, but not the well-known shiitake (Lentinula edodes, Tricholomataceae) or Maitake (Grifola frondosa, Polyporaceae) mushrooms, which have been the subject of numerous activity studies. Under “Mushrooms,” however, they make passing mention of Phillenus linteus (the correct spelling is Phellinus) (Hymenochaetaceae), which they refer to as the “orange color mushroom.”
Given some of the more well-written, edited, and hence reliable titles that the Taylor & Francis group has published, particularly in the domain of botanicals, one might be inclined to expect a more reliable publication from this publisher. Given all the inconsistencies, scientific and taxonomic errors, etc., this book cannot be recommended.
—Kenneth Jones Medical Writer Halfmoon Bay, British Columbia, Canada