Special Feature
Phyto Fantasies
By Sarah L. Berga, MD
The phrase "greening of america" was origi-nally used to describe our national embrace of ecological principles in the 1970s. The "greening of America" now best describes the collective worship by a large segment of our population of phytopharmaceuticals and phytonutraceuticals. While the concept that plants contain many interesting substances that may have medicinal and nutritional value cannot be disputed, the wholesale and uncritical endorsement of all plants and plant-derived substances as beneficial is clearly unwarranted. The following quote provides an interesting perspective. "Anthropobotany. Plants are downright dangerous. Try to think of any food that makes eating irresistible which is not derived from plants! And if plant inventions like chocolate, coffee, wine, and spices would not do enough damage to the neat and trim appearance of human bodies, the plants provide us with addictive substances like nicotine, cocaine, or morphine! So let us not be too sentimental about some other slightly beneficial plant products like digitalis, aspirin, and five million other pharmaceuticals. Look at the inner city problems all over the United States and tell me that these problems were not caused by plants!" (Buehler GA, in the Dynamic Genome. McClintock B. Ideas in the Century of Genetics.) The point of this review is to help the practicing physician address the many "phyto fantasies" that our patients may have and provide some balance and perspective.
Unfortunately, the uncritical predisposition to view plant-based products and herbal therapies as good and "synthetic" products as "bad" has created consumer vulnerabilities that market forces have been happy to exploit. Consider the following vignette. You are asked if you would like a cup of tea. Yes, you reply. Would you like regular or herbal tea? You pause, confused. You think, isn’t all tea "herbal?" You decide not to be snide. Chamomile, you reply, avoiding an inaccuracy by being specific. The unspoken idea is that traditional teas containing traditional tea leaves are not as "herbal" as teas with more trendy leaves. In this example, the word "herbal" has been given a connotation independent of its literal meaning. I remember when green-colored "herbal" shampoos were first introduced. What a marketing bonanza has followed. "Herbal" products cost more and sell well. We have herbal cosmetics, soaps, shaving cream, lotions, and toothpaste, to name a few!
The latest craze in this marketing bonanza, phyto-estrogens, influences the practice of the ob/gyn. Do your patients ask you whether they should take phytoestrogens? Do you ask them if they are taking any products with phytoestrogens? I have added this question to my routine office checklist and the answers can be surprising. Optimally, patients will bring you the bottles so you can see for yourself what the products contain. That too can be surprising. I think many of us are reticent to get too deeply involved in a conversation about phytoestrogens because so little scientific information is known (or we are not certain what is known). Patients also suspect that we may not know enough about this topic. If we display negative attitudes about their habits or beliefs, they may feel highly suspicious or annoyed. So what should we say? I have a few suggestions.
First of all, I think it is fair to acknowledge that phytopharmaceuticals, including phytoestrogens, may have benefits. The concept has merit, but we need to be careful about the implementation of the concept. Any substance "strong enough" to be beneficial is likely to be "strong enough" to do harm when taken in excess or inappropriately. For instance, I recently saw a woman with a phytoestrogen-induced menstrual cycle disturbance. The individual in question had just begun what sounded like a large quantity of new dietary supplements containing soy. The menstrual disturbance and symptoms, including hot flashes, remitted when she discontinued the supplements. The main idea here is not that phytoestrogens are "toxic," but that dose matters. Unfortunately, it may be difficult to find products whose labels are accurate.
One of the merits of whole plants is that they likely contain many beneficial substances. Furthermore, it may be that the full range of benefits are derived from the constellation of "active ingredients" contained within that plant. There may even be synergism between the constituents. So the idea of going to the lab to isolate the active substances may not always be a good one. In nutrition, this idea has led to the recommendation that we eat a balanced diet full of variety rather than depend on a handful of vitamins and supplements to buttress poor food choices. This has recently been referred to as the "food first" paradigm, because there may be some substances such as vitamin D or folate that we need to get in part from "pills." On the other hand, the scientific urge to understand the benefits of certain foods has generally meant trying to isolate the one or two constituents that may be most potent. Rightly so, we want a way to standardize the product and the dose. In medicine, we have yet to derive a resolution of these two fundamentals. Thus, we may feel the urge to equivocate or avoid the topic altogether. This is not an area of medicine that is well funded, but there is at least a growing recognition that we will have to delve into this arena.
To counsel patients and help them with their "phyto fantasies," it is helpful to know what phytoestrogens are. There are two main families. The isoflavone family includes biochanin A, genistein, formononetin, daidzein, daidzin, equol, coumestrol, and prunetin. The lignan family includes matairesinol, secoisolariciresinol, enterolactone, and enterodiol. The estrogenic action of these compounds are in the range of 1/100th to 1/1000th that of estradiol. They also have antioxidant and antiproliferative properties that are still being elucidated. Most importantly, phytoestrogens are not just found in soy! They have been isolated from more than 300 plants, including some we eat routinely in the United States, such as apples, carrots, oats, plums, sunflower seeds, olive oil, potatoes, and coffee. To my mind, the biggest "phyto fantasy" is that one must learn to love tofu to get phytoestrogens. The better recommendation, endorsed by most nutritionists, is that we eat five servings each of fruits and vegetables daily.
There is another element that needs to be addressed with patients. We need to understand the motivation that drives the behavior. Is it distrust of traditional medicine? Is it anxiety and a need to gain control? The director of cancer prevention at the National Cancer Institute (at NIH), Peter Greenwald, recently stated that the "best evidence indicates that at least a third of all cancers have dietary components." Patients may think that phytopharmaceuticals and phytoestrogens in particular are a way to avoid the negatives of "synthetic" drugs such as mainstream estrogen while simultaneously boosting their exposure to mother nature’s healing substances. Patients rarely understand the notion that there can be too much of a good thing when it comes to substances labeled "food supplements."
Since the primary use of most phytoestrogens involves the treatment of menopausal symptoms or consequences, and in consideration of the goal of primer nocere, physicians should acquaint themselves with herbal therapies thought to be harmful. These agents and their potential side effects are shown in Table 1.
| Table 1-Toxic Herbs |
| • Belladonna-3 toxic alkaloids, including atropine |
| • Blue cohosh-vasoconstriction, labor, hypertension |
| • Comfrey-liver failure |
| • Ephedra-cardiac arrhythmias |
| • Lobella-arrhythmias, coma, death |
| • Poke root-extremely toxic, respiratory failure |
| • Sassafras-carcinogen |
| • Scullcap-liver damage |
Table 2 lists herbal products approved by the German Commission E for the use of menopausal symptoms. While the evidence behind these recommendations may be far from what we would consider scientifically valid, at least this agency has led the way in attempting to bring some scientific and medical order to consumer chaos. In the United States, our Congress declined in 1994 the opportunity to regulate food supplements, so these agents now fall under the review of the USDA rather than the FDA. Because of this lack of regulation, purity and labeling remain a huge problem in the United States.
| Table 2-Herbal Therapies Approved by the German Commission E for Treatment of Various Menopausal Symptoms |
| • Balm—anxiety |
| • Black cohosh—anxiety |
| • Chasteberry—emotional balance |
| • Ginko—memory |
| • Ginseng—depression, fatigue |
| • Passion flower—menopausal constellation |
| • St. John’s wort—depression |
| • Valerian—sleep |
References
1. Seidl MM, et al. Can Fam Physician 1998;44: 1299-1308.
2. Tyler, Varro E. The Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies, 3rd ed. 1993.
3. www.nlm.nih.gov (Web site for National Library of Medicine, which provides a user-friendly way for you to search the extant medical literature)
4. www.nal.usda.gov/fnic/IBIDS (Governmental site that attempts to provide a complete compendium about food supplements)
26. Which statement is false?
a. The two main families of phytoestrogens are the lignans and the isoflavones.
b. The "food first" paradigm suggests that nutritional benefits derive from the complex constellation of constituents in naturally-occurring foods and that it is difficult to replicate the nutritional benefits of whole foods with food supplements and vitamin pills.
c. Most of the common fruits and vegetables consumed in the United States do not contain phytoestrogens from the isoflavone family.
d. Soy products, including tofu, are a good source of phytoestrogens from the isoflavone family.
e. Phytoestrogens have antiproliferative and antioxidant properties.
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