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Book Reviews
Advances in Hemp Research
Since Jack Herer's popular work The Emperor Wears No Clothes sparked the modern hemp revival, the need for solid scientific foundations to further develop the many facets of hemp has never been greater. Despite the tremendous amount of research attention hemp has received to date, misinformation still abounds, and decision-makers still face a difficult time getting reliable answers to questions critical to further development. Advances in Hemp Research (Paolo Ranalli, Ed., Haworth Press, 1999, 272 pages) answers these needs brilliantly. Written by more than a dozen distinguished researchers for fellow researchers, scholars, and interested lay persons, readers will find this work a no-nonsense resource, a deep well of facts and details relevant to everyone with practical or general interest in hemp. Nowhere else can one go to get this broad, yet in-depth, treatment of hemp in a concise single volume that is both scientific and accessible.
With a simple and straightforward style, Robert C. Clarke quickly warms us up with a botanical introduction to the hemp plant in Chapter 1, describing its characteristics, life cycle, and history. He also includes a discussion of taxonomy, explaining differences of terminology in common usage and a description of varieties and breeding.
In Chapter 2, David W. Pate discusses the various secondary metabolic compounds (i.e., Cannabis resin) focusing on the nuts and bolts of cannabinoid production. Pate advances and supports the hypothesis that the resins offer survival advantages to the plant. An impressive body of previous research is discussed, considering genetic, environmental and other factors which influence resin production. Some unanswered questions and important areas for further research, such as conclusively mapping biogenetic pathways, are clearly pointed out.
Conventional and innovative methods for detection of THC content are discussed in chapter three by Gianpaolo Grassi and editor Paolo Ranalli. Theoretically, there are over 60 cannabinoids present in the genus, and as they are closely related, issues and difficulties in detecting and differentiating are laid out, with overviews of immunodiagnostic techniques. Significantly, the authors have broken from the prohibition-oriented pattern of detecting THC metabolites in body fluids to detecting natural hemp THC, an important step in developing low-THC yielding varieties through field-selection.
The next chapters present a practical discussion of growing hemp, beginning with Ranalli's observations that developments in hemp types and cultivation have been hampered by prohibition, therefore local conditions and knowledge can contribute to successful cultivation, and technological advance is necessary. Available varieties are introduced, and hemp's place in the rotation addressed before an extensive consideration of cultivation. Soil and growing conditions, seeding rates, nutrients, temperature, and the like are covered, moving into detailed discussions of radiation-use-efficiency, harvesting and further processing of hemp for textile use versus paper pulp. Ranalli wraps up Chapter 4 with analysis of the limits of dry matter production and a list of promising avenues toward increasing hemp productivity, including strategic choice of variety, cultivation and processing techniques.
Chapter 5 explores crop physiology from a somewhat different angle: Hayo van der Werf, Els Mathijssen and Anton Haverkort draw extensively from recent research that demonstrates hemp's agronomic attractiveness and potential as a fiber crop in the Netherlands, summarizing critical yield factors and comparing similar crops.
While hemp is often heralded as 'pest-free', John McPartland's survey of hemp pests and diseases (Chapter 6) shows that hemp is, instead, pest-tolerant, i.e., there are many pests, but the problems they cause are 'rarely catastrophic'. That said, McPartland goes on to discuss a dizzying spectrum of pests, from boring insects attacking stalks and roots to leafy pests, (by and large attacking by sucking plant sap) to fungi, nematodes, viruses, and even mycoplasm-like organisms (MLOs). Pest control mechanisms receive well-rounded attention, beginning with biocontrol methods, pointing out their strengths and weaknesses, with a rational progression to mechanical or cultural control, as first lines of defense. Pesticides are discussed, with a clear and important distinction between synthetic poisons and other methods which may use synthetic compounds, but do not significantly toxify the crops.
In Chapter 7, Etienne P. M. de Meijer lays out the structure of the Cannabis gene pool and reveals its germplasm resources, discussing taxonomy, domestication of hemp, and other issues, culminating in an integrated approach for grouping hemp and a proposed scheme to cover the entire gene pool. Current commercial varieties are surveyed by country, highlighting the dramatic gap between improved European cultivars and Far Eastern hemp, which is said to consist of 'landraces only'. Unfortunately, despite considerable research conducted in China, most of it is "classified information" (!) and remains un-translated, leaving unfortunate gaps in this area.
Conventional approaches to hemp breeding are discussed in depth in a long Chapter 8 by hemp breeder Ivan B?sa, developer of the famed 'Kompolti' varieties in Hungary. After a historical review, sex genetics are explained, laying the groundwork for practical techniques of improvement in stem yield, fiber content, and reduced THC yield. The heterosis effect (increase in yield exhibited by hybrid seed varieties), monoecious and unisexual hemp, and selection methods are covered in detail. This is essential reading for all hemp breeders.
The ensuing Chapter 9, by Giuseppe Mandolino and Paolo Ranalli, focuses on biotechnological approaches, tissue culture and breeding. While clonal techniques are well known, micro propagation remains problematic, though future production of cannabinoids or related compounds should be possible using in vitro cultured hemp cells. The potential benefits of molecular markers for specific hemp traits are undeniable for hemp breeders, though ethical implications of genetic engineering are not discussed directly, and this lay-reader had difficulty extracting the implications of such complex issues.
The final two chapters concern themselves with technical aspects of practical applications for hemp. Chapter 10 addresses the topic of the paper applications of fiber hemp. The broad context of pulp production is provided in this section by Birgitte de Groot, Gerrit van Roekel Jr. and Jan van Dam before specific discussions are presented on pulping hemp bast and core fibers by various techniques. Various hurdles and critical issues, such as delignification and paper quality, are also addressed. The relatively new development of alkaline pulping is explained, and recommendations for subsequent research are presented.
The final Chapter 11, again by Dr. Pate, is devoted to hemp seed as a food resource. Techniques for extracting the seed oil, its composition, properties and nutritive roles are focused upon, providing a wealth of specific information supporting the hypothesis that hemp seed is an important and underutilized source of nutrition, and pointing the way toward future research and development of this "grain" and its production.
Notably absent from Advances in Hemp Research are specific treatments of medicinal Cannabis research, perhaps due to a dearth of such information not oriented toward establishing ostensible harmfulness. Readers may miss a broader range of applied research in other fields, such as textiles and building materials. While commercial interests are driving research into processing technology and applications, much remains to be done. This book establishes and will remain a firm foundation for future research and development, a trusted source for hemp researchers, developers, policy makers, indeed any interested individual who needs "the straight scoop" on hemp.
Michael Sutherland <bikemike@public.km.yn.cn>
Les Èchos du chanvre - Journal d'information sur le chanvre
"Hemp echos", a quarterly "journal for hemp information", is an excellent source of hemp information in French. The journal started in 1995 and is currently printed at 2000 copies. The latest issue (no. 15, autumn 1999) features stories on the Montjean sur Loire (France) hemp festival, a portable fibre extraction machine from Canada, a hemp processing factory in Normandy (France), production of hemp essential oil in Switzerland, problems of Canadian hemp producers exporting to the USA, and a report on the CannaBusiness fair in Germany. The stories are concise (one to two pages) and easy to read. The journal further contains a great number of short news items on subjects concerning fibre, food, medical, legal and other aspects of Cannabis. Previous issues featured several stories on hemp production and processing in several regions in France and on the production and use of hemp-based building materials. The first issue contained a fairy tale by H.C. Andersen, poetically describing the hemp life cycle. This appealing publication is well written, contains information not found elsewhere, and therefore is very much worth its price (4 issues for 100 French francs or 16 Euro).
Hayo van der Werf <derwerf@roazhon.inra.fr>
Base to Tip: Bast-Fiber Weaving in Japan and Its Neighboring Countries
In Base to Tip, the authors present their theories concerning the universality and regional nuance of bast (and leaf) fiber spinning and weaving amongst various east Asian cultural groups. A wide variety of both tree and herbaceous species, including hemp (Cannabis sativa), kudzu (Pueraria thunbergiana), linden (Tilia sp.), paper mulberry (Broussonetia sp.), ramie (Boehmeria nivea), wild nettle (Boehmeria sp.), wisteria (Wistaria floribunda) and abaca/plantain (Musa sp.) are covered in this tour de force of bast fiber knowledge. Technically, abaca and plantain are leaf fibers rather than bast fibers, but they are processed in much the same manner. The authors also deviate from botanical norms by referring to herbaceous fiber plants as "grass-bast" plants and woody fiber plants as "tree-bast" plants, but their intent is easily understood.
The text is primarily Japanese, but Chapter One: Weaving with tree-bast and grass-bast fibers, Chapter Twelve: A model for weaving bast fibers, and Chapter 13: The bast weaving cultures of Japan and East Asia, are in English as well as is the Table of Contents, glossary, references, and all of the captions for the photos, maps, charts and drawings throughout the book, making Base to Tip accessible to a much wider audience. Unfortunately for non-Japanese readers, the details of hemp production in each region are largely not translated, but the Table of Contents informs readers of what they are missing.
The author's main thesis, and hence the title of the book, arise from carefully observing the commonality of bast fiber processors, spinners and weavers paying great attention to the directionality of the fibers from base to tip. They establish a prototype method for bast fiber weaving and explain the basic structural considerations underlying the handling of bast fibers.
"As a plant grows from earth to sky, so all the cells within these plants have a built-in growth direction. Through a microscope one can see they have scales that overlap from base to tip. Stroke these in the direction they grow, and they lie flat, feel smooth. Stroke these against their natural growth direction and they ruff up, stand out. Handling the fibers from base to tip works smoothly and easily. Handling from tip to base creates snags, loose ends, and frays. Awareness of the direction of the fibers is, therefore, of utmost importance in ensuring easy handling."
If a weaver does not work bast fibers from base to tip, or devise a clever way to circumvent this natural condition, then the results of weaving will certainly be substandard.
The authors also explain the key difference between Asian and European bast fiber processing. In Asia, the strips of bast are split into narrow ribbons that are joined together by overlapping and twisting the ends from tip to base to avoid snagging the fibers. Spinning is only used to apply twist to the thread, thereby strengthening the ply-joins. In traditional European bast fiber processing, as well as in modern Asian and European textile factories, the bast fibers are repeatedly combed back and forth from base to tip, and from tip to base, to remove any fibers that create snags before the spinning process is used to overlap and join the individual fibers. Actually, I have read no better explanation of the basic principles of Asian bast fiber joining and weaving.
Their theses are exhaustively supported with numerous beautiful color photos of traditional bast fiber weavers in China, South Korea, Japan and the Philippines. The structural and procedural details of weaving are the authors' greatest interests and they present a comprehensive and detailed illustrated comparison of the various looms and warping styles used to weave bast fibers. My own research focuses on the commonalties and differences of hemp processing and weaving, and their detailed treatment of each step in cloth production has been of great assistance.
Of greatest interest to hemp enthusiasts will be the sections on traditional hemp weaving in the towns of Kaida, Kozuhara and Kutsuki in Japan, and Andong and Sukkok in South Korea. Preparation of the fibers for spinning, the important joining procedure, spinning to add twist to the yarn, and the final weaving are all covered in great detail.
Years of intensive study of the dying tradition of bast fiber weaving in eastern Asia have given the authors an excellent perspective of the position of traditional bast fiber weaving in today's world and what may be done to pre-serve and improve it, as illustrated by the following quotations.
"Considering the general situation at the brink of the twenty-first century, we find it amazing that here and there in the rapidly growing modern Japan people still continue to produce tree- and grass-bast textiles as was done even before the introduction of cotton and silk. Amazing, and also most hopeful."
"In Europe, as in Japan, in contrast with the vast data concerning rare luxury textiles, little has been recorded about the weaving of pliable bast fibers, even thought the quantity of these textiles made for the masses was far greater."
"Undeniably, bast fiber textiles are on the decline. In seeking to preserve their legacy, needless to say, the collection and preservation of actual artifacts must get first priority. Also taking videos and photographs can document important processes and give proof that such traditional culture still lives. In making these visual records, however, it is most important to maintain the perspective of a practitioner. Only that will ensure a truthful record and thereby avoid distortion of the facts. When the approach of the practitioner guides the attitude of those making records and doing research, then a new light transcending time and space might shine on the materials and records displayed in the archives and thereby open up unimaginable discoveries.
"Therefore, in pursuing an understanding of these textiles, it is imperative to know how the thread is made and how the weaving done. That is to say, one must assume from the beginning that one will use one's hands. Inevitably this approach will affect the method of recording data and influence the exhibit of collected objects. The tools in the display case of the finished research collection should be taken out, handled, and put to use, and not just left to gather dust like a display of specimens of insects or plants. After all, tools are beautiful because they are used. Let us bring back the glimmering beauty of the time when the tools were alive"
"First of all, the field work related to producing tree- and grass-bast textiles must proceed speedily, for people who still practice the traditional methods are quickly dying. In many places, it is already too late and the techniques are lost. Where bast weaving still continues to be done or people are still living who can remember the processes, on-site research and recording of verbal memories is important"
"If people do not regain a joy in weaving, and also in the unglamorous supporting arts, such as, ply-joining and the thread binding for kasuri (resist dying), which constitute that which is characteristic and unique to the various areas, then the outlook for the future can only be pessimistic. We must begin to appreciate what can only be thought of as a miracle in the present Japan. This appreciation ranges from gaining respect for the nameless women who have carried on this type of ply-joining and weaving culture, to admiring their traditions and culture. In recent years, the mission of fostering general esteem for the world of bast weaving has, to a large extent, been handed over to various educational media, to schools and to museums in acknowledgment that we, people of the modern age, have the duty to pass on to the future generations the value of these traditions."
The authors certainly convey an effusive enthusiasm for their chosen subject. I echo the author's call to record and transmit this valuable cultural information and sincerely hope that this fine literary work will kindle an interest in other field researchers working with traditional bast weavers.
Base to Tip is a top quality publication, beautifully bound and produced to the highest standards. No more accurate, detailed or comprehensive account of bast fiber weaving is available. This is a costly volume and therefore best suited to libraries specializing in textile science or ethnology. However, I highly recommend this well-researched and colorful "labor of love" as a "must read" for anyone deeply interested in traditional Asian bast fiber spinning and weaving technology.
Robert C. Clarke <iha@euronet.nl>
Hemp Foods & Oils for Health: Your Guide to Cooking, Nutrition, and Body Care
No two areas of information in modern society are more muddled than the topics of drugs and nutrition. With hemp foods, this perplexity is compounded to new heights. The crew at Hemptech are to be applauded for their attempts to sort all of the important information on hemp seed products and render it into such a small volume. At the same time, they are to be criticized for their superficial treatment of a topic that does not need to be intentionally hyped or unintentionally misrepresented. These minor flaws are most likely due to their enthusiasm for the subject.
This little book offers a useful, if superficial, coverage of hemp seed products (the second edition is only marginally better than the first) and is apparently written for oppressed hempsters living in the United States. This work was not intended as an in-depth treatise on the botanical and biochemical aspects of Cannabis seed. Even so, the authors attempt to portray the benefits of hemp seed products in a scientific manner, but without a firm grasp of scientific principles. From a practical perspective, the authors have failed to recognize, or have simply ignored, information that would be useful to the reader. Part of this fault may be due to their lack of experience with hemp foods, and partly due to the considerable effort required for condensing an enormous amount of complex, conflicting and often confusing information into so few pages.
On the front cover of each edition, we are shown a sample of yellowing oil in a colorless glass bottle. Those "in the know" will immediately recognize that only old or highly refined hemp seed oil has such a color, and that the proper way to protect this product is to store it in an opaque container that would not allow the oil to be seen. Along this line, the authors complain about the 'grassy' taste of fresh hemp seed oil. Perhaps only 'vintage' oils are currently available in the United States, which have traveled long distances, or were domestically pressed from dead seed. It would be a pity if the taste and smell of oxidized hemp seed oil became the norm amongst the trendy American public.
On the inside cover of this book, we see the over-used (and in this context, I dare say 'abused') picture of hemp pioneer Joe Stobel, who is staring at the top of a tall hemp fiber specimen, as if to say, "How am I going to get the seeds off of this plant?". Perhaps the most glaring mistake in this little book occurs in the book's "Forward", supposedly written by an expert on health who doesn't seem to realize that the two essential fatty acids are, in fact, linoleic acid and alpha-linolenic acid, not "alpha- and gamma-linolenic acid" [sic]. This type of technical confusion resurfaces throughout the book. For example, concerning protein, I can only wonder what the authors meant when they wrote of 'rare essential amino acids' (aside from the common essential amino acids). Unfortunately conceptual mistakes like these erode the credibility of this book, particularly for those in health care professions.
Concerning THC, which is not a 'narcotic' as mis-stated, we are relieved to find that carefully cleaned seeds should pose no threat to the piss-testing industry in the "Land of the Free". While it is certain that lowered THC levels in food products will significantly decrease the chances of a positive test from the near-homeopathic amounts of THC normally present, there is no evidence to support the contention that such test results will be completely eliminated.
Another biochemical quirk that continues to surface throughout this second edition concerns the matter of Vitamin E. Hemp seed does contain a respectable amount of an E vitamin, but the chemical in question is actually gamma-tocopherol, and not the alpha-tocopherol we all know and love as a dietary supplement and antioxidant. Although the gamma form of this chemical has some antioxidative properties, they are substantially less than the alpha form, and a body would do well to seek the latter.
We are warned that 'deep frying' is not a good idea with hemp seed oil, although 'light saut?ng' is acceptable. This is another unfortunate propagation of misinfor-mation. There is no reason to assume that hemp seed oil is substantially different from other highly unsaturated oils in this regard. In fact, there is a large body of scientific evidence that demonstrates the geometrical isomerzation of the natural and healthy 'cis' double bonds to unnatural and unhealthy 'trans' double bonds at temperatures over 150? C. The biochemical implication of trans fatty acids in the Western oil-fried diet are now apparent, and slowly killing tens of thousands of Americans every year through coronary heart (and other degenerative) disease. At no point in the book are we actually advised on the differences between frying and 'light sautéing', and it is irresponsible to leave this interpretation up to the reader. The authors advise us to keep the frying temperature below 160? C, although a table on page 17 informs us that the 'smoke point' of hemp oil is 165? C, a small margin indeed. Peroxides, which are another class of toxic by-products that result from heating unsaturated vegetable oils to high temperature, are formed even more easily than trans fatty acids. These minor distinctions are important, and the general message should be that we must learn safer ways to use this oil. Personally, I would not heat highly unsaturated oils for more than a few minutes above the temperature of boiling water.
Determined activism and a pioneering enthusiasm has led to a partial substitution of hyped claims for careful scholarship in this book. On the up side, some of the text, tables and figures in this second edition have been revised for the better. Overall, this book is well written, but it would not take that much more effort, or the addition of pages, to convert this work into a classic for the emerging hemp foods industry.
J. C. Callaway <callaway@uku.fi>
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