Number 25
March/April 2000

Herbs in this issue:


Tangerine peel



A Note From Dr. Leung

     Has coffee gotten a bad rap?  I think so.  But before I go on, I want to say I am not a “hired gun” of the coffee industry.  In fact, I quit coffee (a 2-cup-a-day habit for  me) a couple of years ago, not because it is bad or anything like that.  I quit drinking coffee because it simply didn’t taste good to me anymore.  So I switched to tea.  Now I usually drink English tea (with cream and sugar) in the morning and green tea (Japanese or Dragon Well, without the “bad” stuff of course) throughout the day.  So far, this routine still holds for me.  When I travel or whenever my mood strikes me, I do still drink coffee, the strong kind, such as espresso and capuccino or latte, probably averaging only 1 or 2 cups a week. In previous issues of this Newsletter (especially the last one) I have differentiated between the properties and actions of an herb (or food) and its main chemical(s).  Thus, despite the continued misuse of the term “botanical drugs” by even the most highly educated in the medical and biological fields to describe both single-chemical drugs and complex herbs and herbal mixtures, mahuang is


Dr. Leung is author of the Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics (Wiley-Interscience), which was published in 1980 and revised in 1996. He is also creator of PHYTOMED, a prototype computer database on Chinese herbal medicine developed under contract with the National Cancer Institute.


NOT ephedrine (which is only one of mahuang’s many chemical components) and coca leaf is NOT cocaine (only one of coca’s many chemical constituents).  Likewise, coffee is NOT caffeine.  However, the general public has been led to believe coffee is bad for you because of its caffeine, as if coffee had no redeeming qualities other than its flavor and taste after caffeine is removed from it.  We drink coffee for 2 main reasons.  One, we like its flavor and taste; and, two, we want a quick pick-me-up.  Other than these, have you ever thought of coffee being good for you, like green tea, for example?  Here’s something about coffee that you probably are not aware of, and which you should know.

        Besides 1.5%-2.5% caffeine, unroasted coffee contains a wide spectrum of chemical components that include 5% - 10% chlorogenic acid, 0.3% - 1.3% trigonelline, 7.4% - 17% oil, up to 50% polysaccharides (mostly a galactomannan), about 12% protein, about 2% free amino acids, about 9% tannins, and B vitamins, peptides, etc.  After roasting, depending on the extent (e.g., light roast vs. dark roast), up to half of the chlorogenic acid and trigonelline are broken down.  The broken-down trigonelline and certain amino acids turn into aroma chemicals that are responsible for coffees’ characteristic flavors.  However, substantial amounts of the original compounds (chlorogenic acid, trigonelline, polysaccharides, etc.) still remain in roasted coffee which eventually end up in your cup of coffee.  Besides the above major compounds, there are hundreds other chemicals also present.  Thus, more than 100 aroma chemicals alone have been identified in roasted coffee, which include furans, pyrazines, pyrroles, oxazoles, etc.  Considering the fact that there are many types of coffee and roasts, no two different brands or roasts have the same chemical composition.  Is it no wonder that despite all the studies and publications on “coffee” so far conducted and published, we still don’t know whether coffee is good or bad for us?  About the only thing we can study and expect to obtain reproducible results is caffeine by itself (the pure chemical).  However, when we use data from pure isolated caffeine and extrapolate them to coffee itself, we are taking a big leap of faith, because as I have repeatedly stressed, caffeine, the chemical, is not coffee, the bean.  There is no way to control or predict caffeine’s activities when it is present together with all these other chemicals in your cup of coffee.  Some of these chemicals may potentiate a specific effect of caffeine while others may negate it.  We simply don’t know.  Without knowing and controlling precisely what “coffee” is, it is impossible to study the effects of coffee and expect to generate reproducible results.  Which is why we are still debating and wondering whether coffee is good or bad for you.  I personally believe coffee is good for you, especially the lighter-roasted one.  The reason is that it still contains a sizable amount of chlorogenic acid, which is an antioxidant and has been demonstrated to protect experimental animals from substances that cause cancer and to prevent the formation of carcinogens such as nitrosamines from nitrites.  If you are a light to moderate drinker, I wouldn’t try to quit, unless the caffeine causes you problems,.  Coffee is better for you than you may think!  If I were in charge of the Coffee Council (like the Beef Council or other trade groups), if there is such an organization, I would spend $1 to $2 million to study the food supplement potential of coffee.  It would pay big dividends.

        Just a personal note to show how difficult it is to try to apply scientific research findings to human beings, assuming we were all the same.  Many people react to coffee’s caffeine when they drink the “real” thing (non-decaffeinated coffee).  Coffee (caffeine) keeps them awake.  And when they quit, they often experience caffeine-withdrawal symptoms (e.g. severe headache).  Not me!  When I simply quit coffee one day over 2 years ago, I never experienced any caffeine-withdrawal symptoms, nor did I feel anything physically or mentally different.  You may say because I got my caffeine replenishment from tea or offer a myriad of scenarios or explanations.  But the fact is that I had gone off coffee occasionally in the past for days on end without experiencing any such symptoms.  Also, caffeine in coffee doesn’t seem to affect me the way it does most people.  For example, I can drink a cup of espresso late at night and can go right to bed.  I swear sometimes after a dinner out, ending with a cup of espresso, I actually feel sleepy.  It is obvious there are too many variables to try to make sense out of this. 

Leung, A.Y., and S. Foster, Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics, Wiley-Interscience, New York, 1995, pp. 187-190.


Most frequently used herbs in a TCM hospital1

        This hospital of traditional Chinese medicine (Huangshi Municipal TCM Hospital) is located in Hubei Province in central-eastern China, which is close to the Yangtze River (Chang Jiang).  In a recent report, results of the analysis of 40,000 prescriptions written between July, 1998 and June, 1999 at the hospital are presented.  A total of 712 Chinese drugs and 157,512 doses were dispensed.  Total amount of TCM drugs used was 27,160 kg (or about 27 metric tons!).  The total dollar value was 1,590,723 RMB, which is equivalent to about US$198,000.  The cost per prescription can be calculated to be about US$4.95 and the cost per dose (usually daily) is about US$1.26.  The total weight of each prescription filled was 680g and the average weight per dose was 172g, or about 4 doses per prescription. 

        Based on the 106 most-used drugs, the author analyzed their percent weight, dollar amount, and prescription frequency.  For simplicity, only the common Chinese names of the drugs (in pinyin) are given, along with the common English names, unless clarity necessitates the use of Latin binomials.  Basic information on most of the herbs described below can be found in my Encyclopedia

        Based on weight, the following are 30 items each of which represented ~1% or more of the total tonnage used during the study period:  fuling (poria), 2.18%; baishao (white peony root), 2.15%; shengdi (raw rehmannia root), 2.06%; chenpi (tangerine peel), 2.05%; huangqi (astragalus root), 1.99%; shanyao (Chinese yam), 1.93%; yimi (Job’s tear), 1.90%; baizhu atractylodes (Atractylodes macrocephala rhizome), 1.77%; jiaoshanzha (charred Chinese hawthorn fruit), 1.66%; chaihu (root of Bupleurum spp.), 1.66%; gancao (licorice root), 1.59%; zhiqiao (sour orange near-mature fruit), 1.44%; lianqiao (forsythia fruit), 1.43%; huangqin (Chinese skullcap root), 1.37%; yujin (root tuber of Curcuma spp.; rhizome is turmeric or jianghuang, not yujin), 1.37%; danggui (Chinese angelica root), 1.37%; dangshen (codonopsis root), 1.33%; jiegeng (platycodon root), 1.22%; banxia (pinellia rhizome), 1.22%; cheqiancao (plantago herb), 1.21%; gouqi (lycium fruit), 1.12%; kushen (Sophora flavescens root), 1.08%; pugongying (dandelion herb), 1.06%; chishao (red peony root), 1.05%; shudi (cured rehmannia root), 1.05%; dahuang (Chinese rhubarb root/rhizome), 1.00%; chuanxiong (Sichuan lovage rhizome), 0.99%; xingren (apricot seed), 0.96%; huangbo (phellodendron stem bark), 0.96%; and danshen (Chinese salvia root/rhizome), 0.94%.  The weight of the above 30 herbs represented 43.11% of the total weight of all 712 drugs prescribed.  And the weight of the 106 most-used herbs selected for evaluation amounted to 82.06% of the total. 

        Among the 712 herbal drugs, the 30 most frequently prescribed were:  chenpi, 35.30%; gancao, 34.28%; fuling, 31.32%; baishao, 30.89%; shengdi, 29.63%; chaihu, 28.70%; jiaoshanzha, 28.70%; huangqi, 28.57%; shanyao, 27.72%; yimi, 27.30%; baizhu atractylodes, 25.40%; zhiqiao, 24.89%; lianqiao, 24.63%; yujin, 23.62%; huangqin, 23.62%; danggui, 23.62%; dangshen, 22.86%; banxia, 21.08%; jiegeng, 21.08%; cheqiancao, 20.82%; gouqi, 19.30%; chishao, 18.03%; dahuang, 17.27%; chuanxiong, 17.02%; xingren, 16.51%; huangbo, 16.51%; danshen, 16.25%; kushen, 15.45%; pugongying, 15.24%; and muxiang (costus root), 15.24%.  Thus, tangerine peel, licorice, poria and white peony root were the most often prescribed, each being present in over 30% of the 40,000 prescriptions.  I am surprised to see the use of tangerine peel surpass licorice in frequency, though I am not surprised to see licorice rank high on the list, because, overall, it is probably the most used herb in TCM prescriptions. 

        In the therapeutic category, the largest amounts (19.11% by weight) and number (26 drugs) used were those for “clearing heat” (qing re), which, in modern terms, correlates to relieving febrile diseases (including viral and bacterial infections).  The dollar value of this group represented 14.24% of the total.  The second largest amounts (17.87% by weight) and number (15 drugs) used were tonics for boosting deficiencies (bu xu) that correlates to resolving conditions such as lack of energy, lowered resistance, general debility, and chronic illnesses.  The dollar value of this group represented 15.75% of the total.  The other most prescribed categories included drugs for diuresis (li shui shen shi), drugs for promoting blood circulation and removing blood stasis (huo xue hua yu), drugs for regulating vital energy (li qi), and those for treating excessive phlegm, coughs, and asthma (hua tan zhi ke ping chuan). 

        The most frequently prescribed heat-clearing drugs included raw rehmannia root, forsythia fruit, Chinese skullcap root, red peony root, phellodendron stem bark, kushen, and dandelion herb.  The most frequently prescribed tonics included licorice root, white peony root, astragalus root, Chinese yam, baizhu atractylodes, danggui, dangshen, and lycium fruit.  The most prescribed diuretics included poria, Job’s tear, and plantago herb.  The most prescribed huo xue hua yu drugs included yujin (Curcuma root tuber), Sichuan lovage rhizome, and danshen.  The most prescribed li qi (energy-regulating) drugs included chenpi, zhiqiao, and muxiang.  And the most prescribed expectorant, antitussive, and anti-asthmatic drugs included pinellia rhizome, platycodon root, and apricot seed. 

        The data in this report reflect the general principles of TCM in dealing with illnesses, which include regulating the yin-yang balance, sustaining health to remove evils or pathogens (fu zheng qu xie), and strengthening body resistance (immune functions) to restore health and to stay healthy.  Hence the predominant use of qing re drugs to clear heat and toxins in epidemic or seasonal diseases and tonics to strengthen body resistance to diseases in general. 

        I hope the above information would give you a little peek at what happened in a typical TCM hospital, even though the proportions or predominance of certain herbs used in this hospital may not be representative of such use at other times in the same hospital, or in other TCM hospitals throughout China.  The reason is that this study was conducted following the worst flood of the Yangtze in a century.  The predominant use of qing re jie du drugs reflects a large proportion of epidemic diseases such as bacterial and viral infections, and fever, etc. 

(1) J. Zhang, “Analysis of 40,000 Herbal Prescriptions Used in Our Hospital,” Shizhen Guoyi Guoyao, 10(10): XI-XII(1999);  Leung, A.Y., and S. Foster, Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics, Wiley-Interscience, New York, 1995.


Flip-flopping in healthy-eating rules?

      Whom should you believe?  For years we have been told that salt is bad (high blood pressure!), coffee is bad (caffeine!), eggs may be worse (heart attack!), butter is bad (cholesterol!), margarine is good (no cholesterol!), estrogen is bad (and now good!), and “fiber” is good (prevents cancer! lowers cholesterol!), etc., etc.  Now, one is not so sure! 

        In a recent article on fiber by a reporter of the Associated Press, reprinted in The Record of New Jersey, the title proclaims “Another magic bullet misses mark” followed by “Fiber, miracle food no more, one of many recent letdowns.” 2  This gives you the impression that we should no longer include fiber in our diet.  But what is fiber in the first place?  Unlike specific, well-defined chemicals or drugs such as caffeine, aspirin, or cocaine, fiber and other food substances being studied in humans are seldom clearly defined.  Add to this the high variability of the complex human organism, you have many strikes against you in trying to obtain meaningful results.  I can see the rationale behind the use of statistics to determine the validity or significance of a study using a pure chemical drug ON a complex human being, where at least the non-human part is constant.  On the other hand, I can’t see the justification of using statistics to rationalize the results of studying complex variable natural materials ON an even more complex human organism.  With the potential myriad of permutations among the countless variables, how scientific can these studies be and how valid their results?  This is an aspect of clinical trials on natural materials that has always bothered me.  Just imagine taking a relatively simple artificial mixture of ONLY caffeine, chlorogenic acid, theophylline, catechin, huperzine A, ginsenoside Rb1, cocaine, ephedrine, hypericin, ursolic acid, cimetidine, berberine, aspirin, and guar gum, and try to study the effect of caffeine in humans!  This is simply out of control!  This mixture is not even half as complex as a natural material like ginseng or eleuthero.  Yet, can any researchers honestly say they have a controlled study under this kind of situation?  Not unless they are totally ignorant in, or oblivious to, the non-human aspects of their study.  By this I mean the natural materials (“drugs”) they are studying.  Up to this day, many researchers (including pharmaceutical and medical) continue to regard natural materials (be it an herb or herbal extract) which they study, as pure chemicals, knowingly or unknowingly, 21 years after the publication of the infamous study of “ginseng” that resulted in the term “ginseng abuse syndrome!”  In that study, the author considered any commercial product with a label of “ginseng” as ginseng, presumably Asian ginseng (Issue 18, pp. 1-2)!3  Without at least controlling the natural materials under study, no wonder there are so many controversial research findings.  It is like the researchers have been comparing oranges with apples all these years!  It is no wonder we keep getting conflicting health advises.  Because there are no uniform criteria or standards for evaluating/selecting substances like fibers, coffees, teas, or ginsengs as materials to be studied (Issue 19, pp.2-3), one researcher’s results may be positive while another’s negative.  And when these reach the popular press, the results are frequently misinterpreted, exaggerated, suppressed, or manipulated, to suit its own agenda.  The end result is a very confused public, even me, though I am more skeptical than confused!  Take the case of fiber.  The reporter of above article makes it sound like fiber is a single, chemically well-defined drug that is expected to produce a very specific pharmacological effect (hence he refers to it as “magic bullet”) that is supposed to prevent colon cancer.  When 2 recent studies didn’t show such effect, he declared the “magic bullet misses mark.”  But fiber is not a single-chemical drug like aspirin or morphine!  Unless all scientists agree to clearly define what fiber is whenever it is being studied, the results would be different each time, no matter how many times “fiber” is being studied.  The attitude we should assume concerning any kind of clinical trial with natural substances, especially with foods and food ingredients, is to consider any of their findings simply as potentially useful information to add to our collective traditional wisdom or common sense.  They should never be taken as new definitive scientific wisdom, at least not until the scientific world agrees on what they are actually studying when it comes to natural food materials.  For now, like always, moderation is the key to good health.  I don’t know about you, but I continue to eat eggs whenever I want to, though not excessively.  I prefer butter to margarine because I simply have never believed that margarine is better or even good for you, and I don’t eat that much butter anyway.  Regarding fiber, I don’t have any regular diet regimen for that either, though I eat whatever fruits and vegetables that are available to me.  All these plus a little (just a little) guilt feeling that I should eat more of this, or less of that, due to years of subconscious indoctrination by bad science, especially via the popular media. 

(2) D.Q. Haney, “Why Healthy-Eating Rules Change So Much – Another Magic Bullet Misses Mark,” The Record, New Jersey, April 22, 2000, p. A-9;  (3) R.K. Siegel, “Ginseng Abuse Syndrome,” JAMA, 241: 1614-1615(1979).


         Berberine in lowering the fasting plasma glucose level of type II diabetes patients [Zhongguo Zhongxiyi Jiehe Zazhi, 19(9): 567(1999)].  This report is by Yun-Fei Zhang from the Air Force Hangzhou Sanatorium, Zhejiang Province.  Twenty patients diagnosed with type II diabetes per WHO criteria were treated with berberine.  There were 14 males and 6 females, ages 49-72, with course of illness from 2 to 7 years.  The patients’ pretreatment fasting plasma glucose levels were 10.0 2.9 mmol/L.  Their body weight index was basically normal and there were no obvious complications.  They were given berberine tablets 3 times daily (after meals), 1g each time.  The treatment course was 3 months.  The patients’ fasting plasma glucose (FPG) was determined before treatment and 1 month, 2 months, and 3 months after treatment started.  When the FPG level dropped to normal, the dosage was reduced to 0.5g, 3 times daily to consolidate treatment results.  Among the 20 patients treated, the FPG levels in 9 patients dropped 0.5-1.5mmol/L after 1 month.  After 2 months, the FPG levels in 9 more patients dropped similarly.  And after 3 months of treatment, all 20 patients’ FPG levels returned to normal (7.8 0.4mmol/L).  The author observed that berberine’s hypoglycemic effect was dose dependent.  However, once the FPG levels reached normal values, increasing the berberine dosage did not lower the FPG further.  It was also observed that the drug had no obvious effect on patients’ body weight, blood pressure, liver and kidney functions. 

        Berberine is normally available in 100-mg tablets.  As I have previously described (Issue 22, pp. 2-3) berberine has been widely and effectively used in China as an anti-diarrhea medicine for decades.  It now appears that this compound may find a place in diabetes self treatment as well.