The Pill Book Guide to Natural Medicines: Vitamins, Minerals, Nutritional Supplements, Herbs, and Other Natural Products by Michael Murray

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Read an Excerpt

How to Use This Book

The Pill Book Guide to Natural Medicines profiles more than 275 of the most commonly used natural products available today. The entries are listed alphabetically within each of the following categories: vitamins, minerals, accessory nutrients and other natural products, herbal products, and topical preparations. If you are interested in a particular supplement and do not know to which category it belongs, please consult the Index of Natural Products at the front of the book.

Here is a brief description of each category. Particular issues related to each category are discussed in more depth at the beginning of each part. You will find it useful to read these overviews as well as the profile of the individual supplement that interests you.

Part I: Vitamins. Vitamins are essential nutrients that function along with enzymes in chemical reactions necessary for human bodily function, including energy production. Together, vitamins and enzymes work to act as catalysts in speeding up the making or breaking of chemical bonds that join molecules together.

Part II: Minerals. Minerals function, along with vitamins, as components of the body's enzymes. Minerals are also needed for proper composition of bone and blood and for the maintenance of normal cell function.

Part III: Accessory Nutrients and Other Natural Products. Accessory nutrients are food components and substances naturally produced in the body that are required for normal physiology. Other natural products include supplementary hormones, glandular preparations, amino acids, and helpful bacterial preparations such as Lactobacillusacidophilus.

Part IV: Herbal Products. These include not only crude herb preparations but also compounds composed of or derived from herbs and other medicinal plants.

Part V: Natural Ingredients Used in Topical Preparations. While Parts I-IV cover products for oral use, this part provides information on natural substances used in skin care products and topical medications.

You can also use this book to discover alternative medicines that may be helpful in treating a specific health condition. This information is contained in Part VI: Common Health Conditions. This part provides an alphabetical guide to more than sixty-five common health conditions; each entry includes both the prescription drugs and the natural medicines most often used for each condition.

Organization of the Natural Product Entries

Parts I-IV include natural products taken orally. Each product entry is organized according to the following outline:

Generic or Brand Name

The common name of the natural product is used for most entries (e.g., "vitamin C" instead of "ascorbic acid"). A supplement is listed by brand name only when a brand has established itself as a unique proprietary product.

Used For

A listing of the popular uses for each entry is given. In an effort to provide information on the effectiveness and safety of the entries, a rating system was developed based upon currently available information. The rating is based upon the level of scientific support for a particular application. The fact that a substance has not been scientifically investigated does not mean that it is without benefit. Likewise, the fact that a substance has been used for hundreds of years does not necessarily mean that it is either effective or safe. The scientific investigation of natural products is an ongoing effort, and new information is constantly validating or refuting claims about the therapeutic value of these preparations.

Here is an expanded explanation of the rating scales:

Effectiveness

A = Excellent results in multiple double-blind studies

In order to receive an A rating, the substance must have undergone a clinical trial--a study in which human subjects receive treatment. The studies with the most scientific weight are double-blind, controlled trials. In a double-blind study, neither the researchers nor the subjects know what is being given; all information is coded, and the code is not broken until the end of the trial. Double-blinding is important because researchers can give unconscious signals to test subjects if they know what the subject is receiving, and this can affect the results. In a controlled trial, at least two groups are compared.

In a double-blind, placebo-controlled trial, an inactive pill--the placebo--is given to a control group. Placebo is Latin for "I will please [you]." Placebos got their name because any treatment, even simple attention, tends to make people feel better. Overall, an average of one out of three subjects will report significant improvement from being given a placebo (usually a sugar pill), although this figure can be much lower or much higher depending upon the condition. Sometimes instead of a placebo, a substance will be compared to another active compound. For example, there have been several comparative studies of glucosamine sulfate and ibuprofen in the treatment of osteoarthritis.

The double-blind study is thought of as the gold standard. However, a good double-blind study must also have a large enough sample size (the bigger the better) to produce statistically significant results. Often a probability value (p value) is given. A p value less than 0.1 means that the probability that the results occurred by chance is less than 1 out of 100 (1 percent). A p value of less than 0.5 is generally regarded as being statistically significant. The lower the p value, the more significant the results.

When a number of small trials have provided conflicting or inconclusive results, a metanalysis can be performed in order to achieve a more statistically significant assessment.

In order for a substance to receive an effectiveness rating of A, it must have shown consistent benefit in double-blind, controlled trials or in a metanalysis.

B+ = Very good results in a small number of double-blind studies

The difference between an A and a B+ is that although there are double-blind studies showing that the substance rated as B+ is effective, these preliminary studies need to be followed up with larger, better-designed studies. Also, a substance would be given a score of B+ rather than A if the studies were poorly designed or did not produce a high degree of statistical significance.

B = Some clinical evidence of effectiveness

There are other types of clinical studies that are often conducted as preliminary studies. Sometimes, because of the lack of financing or other reasons, promising results are never followed up in better-designed studies. Examples of preliminary studies can range from a series of individual case histories to open clinical trials. In an open clinical trial, both the doctor and the subject know exactly what the subject is taking. Open trials are not as well respected in the scientific community because of the expectations of the patient and/or the physician.

B- = Some clinical evidence of effectiveness, but also some studies showing no effect

It is not uncommon for even established drugs to have some studies showing no or little effect. If the majority of the studies have been positive, the substance was given a rating of A or B+ depending upon the weight of evidence. However, if a number of preliminary studies showed positive results and a double-blind study showed little or no effect, the substance was given an effectiveness rating of B-. In the future it may be proven to be effective, but at present there is simply not enough evidence that is convincing.

C = Strong historical use or scientific rationale but no clinical trials to show effectiveness in humans

This rating is probably the most common in this book. There are numerous natural products that should be better evaluated in clinical trials but have not been. A rating of C does not indicate that a substance is any less effective than one with a rating of A or B; it simply signifies that we really do not know how effective it is, but there is reasonable probability that it may offer benefit.

D = No significant documentation of historical use or scientific rationale, or majority of clinical studies show no effect

A rating of D is cause for concern. In general, unless instructed to do so because of some extenuating circumstance by a health care professional, substances receiving a rating of D should not be used.

F = Documentation that it is not effective

A rating of F is straightforward and reflects considerable evidence that the product is not effective for a particular application. Unless new, convincing evidence becomes available in the future, these products offer no value for the noted application.

Safety

A = Excellent safety profile

In order to receive an A for safety, a substance must be generally regarded as safe by most authorities (e.g., the FDA or the National Academy of Sciences) or have been extensively evaluated in toxicology studies in animals or humans.

B = Good safety profile

Clinical studies have been conducted on the product and no significant side effects have been reported, or there are preliminary toxicology studies on the product.

C = Generally regarded as safe at recommended levels

Most often, products receiving this classification have a long history of use without any serious side effects at recommended levels.

D = Generally regarded as safe at recommended levels, but must be used with caution

A rating of D for safety does not mean that the product is unsafe; it simply implies that there may be situations where it should not be used or that it should be used with caution or under the supervision of a health care professional.

F = Potentially dangerous, should not be used

Products with a rating of an F should not be used unless recommended and closely monitored by a health care professional because they pose a significant health risk.

General Information

This entry will usually contain the most useful information to assist you in determining the merits of the product for a particular indication. It provides a full description of the product's effects and uses, including results from clinical trials in humans where available.

Available Forms

Natural products are available in many different physical forms (e.g., capsules, tablets, liquids, powders, etc.). In addition, there may be different forms of a specific nutrient or herb. For example, there are five major forms of calcium on the market. Information is provided to help you make an informed choice. Brand names are given when there has been a significant amount of scientific research conducted on it or the product has established a dominant position through marketing and/or unique features.

Cautions and Warnings

Although generally safe, some natural products carry warnings and cautions. This heading will alert you to any concerns.

Possible Side Effects

A description of possible side effects is presented to alert you to any problems that may occur when using a particular natural product.

Drug Interactions

One area that is particularly important for consumers is the interaction of drugs with natural products. If you are on any prescription medication, it is recommended that you talk to your physician or pharmacist about your use of natural products to avoid any adverse interaction. Although drug-nutrient interactions and drug-herb interactions are not as common as drug-drug interactions, all can have an impact on therapeutic outcome.

Most interactions are the result of a change in the pharmacokinetics of one of the substances. Pharmacokinetics refers to the absorption, distribution, metabolism, and excretion of compounds, whether they are drugs, nutrients, or herbs. The most straightforward interactions are those whereby one compound inhibits the absorption of the other. For example, the drug sulfasalazine (Azulfidine) decreases the absorption of folic acid. Such effects are often referred to as "drug-induced nutrient depletion" or "drug-induced nutrient deficiency." Of course, certain nutrients and herbs can also inhibit the absorption of drugs.

There are several other causes of interactions. In regard to herbal products, a particularly troublesome situation can occur when herbal constituents interfere with or enhance the manner in which the liver breaks down certain drugs. For example, recent medical case reports and pharmacological studies suggest that St. John's wort extracts may increase the rate at which the liver breaks down certain drugs and as a result reduce the blood levels of these drugs. Some of the drugs that may be affected include cyclosporine, digoxin, oral contraceptives, theophylline, and anticoagulants such as warfarin. The opposite effect--increasing blood levels of a drug--may also occur.

Some prescription drugs work by interfering with the body's utilization of nutrients. The best-known drug with this sort of action is the anticoagulant drug warfarin (Coumadin). This drug works to thin the blood by interfering with the body's ability to utilize vitamin K. Hence, people taking Coumadin are advised to avoid consuming green leafy vegetables and vitamin formulas that contain high levels of vitamin K.

While negative interactions get more attention, positive interactions between drugs and natural products can produce significant benefits. For example, there are numerous cases where natural products can reduce the severity of side effects or prevent them from developing in the first place. Perhaps the best-known example of this sort of interaction is the use of lactobacillus ("friendly" bacteria) supplementation to prevent or treat diarrhea induced by taking an antibiotic. You can use the general index to this book to look up a prescription drug you may be taking and find potentially helpful interactions. For example, if you are taking the chemotherapy drug paclitaxel (Taxol), the index would refer you to the entry for the amino acid glutamine, which has been shown to prevent the mouth ulcers (stomatitis), muscle and joint pain, and suppression of the immune system almost always seen in people taking paclitaxel.

I hope these examples make it clear why it is so important to inform your physician or pharmacist about any natural products you are taking, in addition to using this book to check for potential interactions.

Food and Nutrient Interactions

The presence of food in your stomach may interfere with or enhance the absorption or action of some natural products. This entry tells you whether a supplement should be taken with meals or on an empty stomach. It also includes a description of any interactions with other nutrients. For example, calcium supplements may inhibit the absorption of other minerals, including copper and zinc, while vitamin B6 and magnesium work cooperatively. Thus, nutrient interactions may be either antagonistic (negative) or agonistic (positive).

Usual Dosage

In order for natural products to produce the best results, it is important to take them in the proper dosage. Such information is provided along with different dosages for particular applications or available forms.

Overdosage

A description of the symptoms of an overdose, when applicable, and information on what to do in an emergency situation are provided. The fact that a substance is natural does not mean that it is not potentially dangerous. Although most natural products are safe at recommended levels, accidental overdosages have occurred. Usually when there is any question of safety (such as with supplements that contain iron) manufacturers of natural products will use child-resistant containers.

Special Populations

Pregnant or breast-feeding women, children, and seniors have special concerns with natural products as well as prescription and over-the-counter drugs. Pregnant and breast-feeding women need to know if a product can harm the fetus or infant. Children are more susceptible to overdosage and side effects. In general, no supplement should be given to a child less than two years of age without specific approval from your physician, and some supplements should never be given to children. Seniors are often taking one or more prescription drugs; they need to be especially aware of potential interactions. Because of age-related changes in the body, they may also metabolize both natural products and prescription drugs differently than a younger person.