By Dr. Catherine Ulbricht Chief Editor of Natural Standard and Journal of Dietary Supplements Senior Attending Pharmacist at Massachusetts General Hospital
The term complementary and alternative medicine (CAM) refers to a broad group of medical practices that are used either alongside or instead of conventional therapies. Natural products –including botanicals, minerals, vitamins and other supplements from natural sources – form a major part of CAM. Despite the popularity of natural medicine, there is a lot of confusion regarding how safe, how effective, and even how common it is. Here, we address some common myths about natural medicine.
Myth: Few Americans use natural medicine or other forms of CAM.
A few years ago, the National Center for Health Statistics conducted a survey on CAM use in the United States. This survey showed that in 2007, over 40% of American adults used CAM –most commonly as nonvitamin, nonmineral natural products (such as herbal extracts and amino acids). That year, the out-of-pocket expenses for CAM products and services were nearly $34 billion in the United States. To put this number in perspective, the 2007 budget for NASA – just over $16 billion – didn’t even amount to half of what Americans spent on CAM. These numbers continue to rise.
Myth: If it’s natural, it must be safe.
There’s a common assumption that “natural” means “safe.” With so many poisonous (and often deadly) plants found in nature, this assumption is clearly incorrect. Even some natural products that are marketed to promote health may increase the risk of liver toxicity or kidney toxicity. Furthermore, there have been many recorded cases of bleeding and/or drug interactions with certain herbal products and dietary supplements (see next myth). Pregnant or breastfeeding women need to use extra caution. Extracts may contain high volumes of alcohol. Like pharmaceutical drugs, natural products can be helpful but need to be used safely and be monitored by health-care providers.
Myth: It’s okay to take natural medicines along with conventional therapies.
The term “complementary medicine” implies that it should be used alongside conventional therapies. However, it is important to know that many natural products can affect how drugs work. One example is St. John’s wort (Hypericum perforatum), which may alter how many drugs are metabolized. St. John’s wort thus has many potential interactions, and its use is contraindicated (restricted) with several drugs. Grapefruit also has several well-known drug interactions. Grapefruit juice may slow the metabolism of many chemicals, thus increasing the blood serum concentrations of certain drugs.
Natural Standard Research Collaboration conducted a systematic review of clinically documented herb-drug interactions. We noticed that in addition to grapefruit, herbs beginning with the letter "g" (garlic, ginger and ginkgo) were among the supplements most commonly involved in herb-drug interactions. Garlic, ginger and ginkgo have all been associated with increased bleeding, and all have been clinically shown to interact with blood-thinning drugs.
Myth: Doctors and patients don’t need to discuss the use of natural therapies.
Because many natural products are available over-the-counter, patients often may think, “Since I didn’t need a prescription to get this, I don’t need to discuss it with my doctor.” At the same time, studies have shown that physicians are often unaware that their patients are using natural products or other forms of CAM, like chiropractic therapy or acupuncture. Since many natural products have well-known adverse effects and drug interactions, there needs to be better communication between patients and all health-care providers to assure a personalized safe and effective integrative care plan.
In general, both patients and clinicians should be cautious about using any natural products with blood-thinning drugs like warfarin, which is widely known to be sensitive to vitamin K intake. Any blood-thinning drug may potentially interact with any herb or supplement with anticoagulant properties, such as vitamin E, fish oil or omega-3 fatty acids. Because many natural products may increase the risk of bleeding, clinicians should ask their patients before surgery (including dental surgery) whether they use herbs or other natural products. Discontinuation of these products should be considered well before any surgical procedures.
Health-care providers should include the topic of CAM as part of a new patient assessment. For example, when discussing medications, physicians should ask about everything the patient ingests – including over-the-counter products, vitamins, minerals, herbs, and even the patient’s diet. Yoga? Acupressure? Traditional Chinese Medicine (TCM)? Physicians may consider having the patients bring in the actual bottles of herbs and supplements for evaluation. A list of all therapies and practices should be provided by patients during office visits and at store counters.
Myth: Pharmacists just dispense drugs.
Pharmacists – many of whom hold the Doctor of Pharmacy (PharmD) degree – are often the last clinicians that patients encounter before taking medications/dietary supplements home. Therefore, Pharmacists are in the position of being the final “safety net” for drug interactions, nutrient depletions and adverse effects, and should constantly be on the lookout. They need to be proactive about counseling patients on potential interactions between drugs and foods, herbs, and dietary supplements. At the same time, patients need to tell pharmacists what natural products they are using; otherwise, dietary supplements won’t show up in patient records. Patients should keep an active list of medications (prescription, over-the-counter, or CAM) and ask the pharmacist if there are any potential adverse effects, interactions, or other considerations when using any other drugs or natural products. Note that retail clerks are not necessarily well trained in this area.
Myth: Natural medicines are regulated the same way as conventional drugs.
Patients often don’t know that dietary supplements and natural products are regulated differently from drugs. Prescription and over-the-counter drugs are regulated by the United States Food and Drug Administration (FDA), which requires evidence of effectiveness, safety and quality control in manufacturing. In contrast, dietary supplements (such as vitamins, minerals and many herbal products) are governed by the Dietary Supplement Health and Education Act (DSHEA) of 1994. Under this act, dietary supplements aren’t subject to the same scrutiny that the FDA imposes on medications. Thus, many natural medicines can exist on the market without proven safety or effectiveness.
Though supplements cannot be intended to treat, prevent, or cure diseases, the FDA does allow certain “qualified health claims subject to enforcement discretion” for some natural products. For example, conventional foods and dietary supplements that contain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acids may carry a qualified health claim for reduced risk of coronary heart disease. “Structure-function” claims on dietary supplements may also describe how a substance maintains normal structure or function “as long as the claims don't imply the product treats or cures a disease.”
Products promising to cure or prevent any health condition – particularly those with no conventional cures – may be making fraudulent claims that are not based on scientific evidence. By understanding what claims can or cannot be made on supplement labels and advertisements, consumers can learn to spot fraudulent supplements.
Consumers may also look for marks of certification by groups like the United States Pharmacopeia (USP) on product labels. These marks certify that a dietary supplement has been independently tested and verified to contain the ingredients on the label, and meets requirements for purity and good manufacturing practices. Other third party testers like NSF, Consumer Labs, and Consumer Reports for example are all listed on Natural Standard, along with specific brands studied in clinical trials. We recommend checking Natural Standard or books before purchasing products to aid in the selection process. (Natural Standard consolidates the evidence using an easy to understand A-F report card grading scale based on that of the US Preventative Services Task Force.)
Myth: Natural therapies are not supported by scientific evidence.
Scientific evidence supports many natural products for several health conditions. For example, there is strong clinical evidence that peppermint (Mentha × piperita) may improve symptoms of irritable bowel syndrome (IBS). Another example, kava (Piper methysticum) is also supported by clinical evidence for reducing anxiety; however, due to widespread concern regarding potential liver toxicity, kava has been withdrawn in several European and North American markets.
Although scientific evidence supports many natural therapies, there are still many CAM products that lack evidence despite their widespread use. More research is needed for natural therapies in general to determine safety, effectiveness and proper dosing. Manufacturers need to be held to Good Manufacturing Practices (GMP) and encouraged to conduct clinical trials on their products.
Myth: Natural products have no place in conventional medicine.
Natural products are often regarded as “alternative” therapies that aren’t supported by science. However, it is important to note that many of the drugs that are currently available – in fact, even the most commonly used drugs – are derived from nature. In the last decade alone, more than 20 newly approved drugs were derived from natural sources, including plants and microorganisms. It has been estimated that 50% of contemporary drugs (those used in the last few decades) are either directly extracted or chemically derived from naturally occurring compounds.
Notable examples include the opiate painkillers, such as morphine and oxycodone, which are derived from the latex sap of the opium poppy (Papaver somniferum). Opiates represent one of the best-selling classes of prescription medications. Another example is aspirin (acetylsalicylic acid), which has been described as “the most popular painkiller in the world.” Aspirin is the world’s first-ever synthetic drug, and is derived from salicylic acid, which is found in willow (Salix spp.) and meadowsweet (Filipendula ulmaria, formerly Spirea ulmaria).
Decades ago, the U.S. National Cancer Institute (NCI) recognized nature as a major source of potential anticancer compounds, and established the Natural Products Branch (NPB) in 1960 to screen natural product materials for pharmacological activity. Paclitaxel (Taxol®), derived from the Pacific yew (Taxus brevifolia), is a prominent example of a successful plant-based anticancer drug from the NPB. Yew has been used in traditional medicine for centuries, and in 1966 the NCI singled out Pacific yew in a massive screen of 35,000 natural products. Paclitaxel and its semisynthetic derivative docetaxel are now first-line treatment options for a number of cancers—including breast, ovarian, and lung.
Natural products are important sources of pharmacologically active compounds, which often form the basis of both CAM and conventional medicine. On one hand, natural products are often used as primary therapies (or to complement conventional therapies) despite uncertain effectiveness or safety. On the other hand, natural products have given rise to numerous conventional drugs, which are widely used today as first-line treatments for numerous conditions. As herbal products (and dietary supplements in general) continue to grow in popularity, patients and health care providers need to be aware of potential herb-drug interactions and other safety issues. More research is needed to determine the effectiveness of many CAM therapies, and how to reach a balance between the potential benefits and risks. Reliable sources of information are also crucial for patient and providers to make educated and evidence-based decision