How safe are “natural” or complementary and alternative treatments?

| Posted On Dec 06, 2011 | By:

herbs, roots, alternative medicineComplementary and alternative medicine (CAM) is a label applied to a broad range of treatments that are felt to be outside the scope of conventional or Western medicine.  Some examples of CAM are:

More than one-third of the adults and 20–40% of children in the United States have reported using CAM.  These treatments are widely perceived as “natural” and therefore considered to be intrinsically safe.   Unfortunately, CAM products and techniques have caused serious harm to many people. 

Dietary Supplements/Herbal Remedies

Although the perception is that “dietary supplements” – including herbal remedies, vitamins, minerals and other natural supplements – are safe, many of these products have been shown to have severe side effects with frequencies comparable to those of typical pharmaceuticals.   For example, herbal remedies kava and valerian both have been linked to severe liver damage.  Even vitamins at doses not much above recommended levels have shown harmful effects (for example, increased cancer risk). 

In the United States, dietary supplements are not regulated in the same manner as medications. These supplements are not required to prove safety or efficacy. Since the passage of the Dietary Supplement Health Education Act of 1994, they may be banned by FDA only if there is concrete evidence that they cause harm. The legal definition of dietary supplements is fairly narrow and clear. In practice, the definition is interpreted in a sufficiently elastic way that substances such as melatonin and DHEA (dehydroepiandrosterone) qualify and are sold as supplements, yet these substances clearly have risks similar to many other substances which are regulated as drugs.  

Because regulation and oversight is lacking for these types of products, negative effects can sometimes be attributed to either the inadvertent contamination of or sometimes the intentional addition of other substances to the herbal therapies.  Some examples:


It is unclear whether the problems or adverse effects of physical or body-based CAM, such as chiropractic manipulation or acupuncture, are a result of improper technique or would have occurred even if the practitioner performed the therapy exactly according to the intended method. Numerous instances of injuries to arteries or the spinal cord have been reported in connection with chiropractic manipulation.   Even a technique as seemingly benign as massage can lead to serious problems.  

In other cases, it is clear that the adverse effects are a result of error or poor technique. A 9-year-old boy died after the wall of his heart was pierced by an acupuncture needle placed in the upper abdomen. 

Finally, the use of CAM treatments can have grave consequences if the patient forsakes known effective mainstream medical treatments and the CAM treatment is not effective. For example, a German report documented three instances in which children with insulin-dependent diabetes were advised by CAM practitioners to stop taking their insulin in favor of various alternative treatments. All three children died of diabetes within days of discontinuing their insulin. Many CAM practitioners advise against immunization, instead recommending chiropractic or other CAM, with the expected consequence that some children develop serious vaccine-preventable infections.

Evaluating CAM Therapies

How do we know if a given CAM therapy is safe?  We should apply the same standards as for conventional therapies: empiric evidence resulting from methodologically sound controlled trials, or in the absence of controlled trials, statistically rigorous analysis of existing data is the only way to demonstrate safety.

The Mayo Clinic has provided a plethora of consumer-focused information about CAM, not just what it is, but how to evaluate treatment options, practitioners, and claims.  If you are considering use of a CAM product or technique, I have high-spotted some of their key points for consideration:

Further reading

Natural Causes: Death, Lies and Politics in America’s Vitamin and Herbal Supplement Industry, Dan Hurley, 2006, Broadway Books, New York.

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About Dr. Ben Kruskal

Ben Kruskal is a pediatrician at the Somerville practice and an infectious disease specialist. He is the Director of Infection Control and Travel Medicine at Harvard Vanguard. Dr. Kruskal went to college at the University of Pennsylvania and attended medical school at New York University. He did his pediatric residency and pediatric infectious disease fellowship at Boston City Hospital (now Boston Medical Center). Dr. Kruskal served on the faculty at Children's Hospital and Massachusetts General Hospital before he joined Harvard Vanguard in 1997. He collaborates with researchers at Harvard Medical School's Department of Population Medicine, focused chiefly on the use of electronic systems for disease surveillance. Dr. Kruskal has co-authored twenty peer-reviewed publications and a book chapter. He is passionately interested in quality of care and patient safety, and has served on Harvard Vanguard's Quality Assurance Committee since 2000. As a pediatrician, Dr. Kruskal garners a lot of credibility when patients learn he has five children.


  1. Ben,

    I fully agree with the idea that the best way to prove effectiveness is with appropriately constructed study.

    Do we know the relative frequency/severity of complication from CAMs? this may be hard to get as we don’t know
    you have focused on case reports (the 9 yr old who died…) as a way of making arguement for caution using CAM’s. What might you say to a non-believer who says “you shouldn’t take medications; just look at all the post op infections that happen in the hospital”.

    Comment by james pert on December 8, 2011 at 4:42 pm
  2. Jim,
    There have been limited attempts to collect statistics on CAM safety; I’m aware of a few case series, but nothing statistically rigorous. I have focused on anecdote because it’s all we really have. I’m not attempting to make a rigorous comparison between safety of CAM and allopathic treatments because there isn’t really enough data to do so. My goal is to dispel the myth that CAM treatments are intrinsically safe. We all know that there are risks to conventional medical treatments; CAM has risks, too, some of them as serious as anything we see with allopathic treatments. We need systematic study of safety and efficacy of the most promising CAM treatments; where the data compares favorably enough on those counts, head to head comparisons of CAM and allopathic treatments for the same conditions would be the logical next step.

    Thanks for your question.

    Comment by Harvard Vanguard on December 14, 2011 at 1:32 pm
  3. Hello Dr. Kruskal,
    I appreciate that you are trying to dispel the issue that CAM therapies are safe because they are “natural”. I agree that we have to be savvy consumers and there needs to be better regulation of supplements. I felt that your article was slanted against CAM when many CAM therapies can be a wonderful adjunct to allopathic treatment and can remedy many of the side effects caused by allopathic medications. I.E., acupuncture and reiki have been shown to relieve some of the side effects from chemotherapy in oncology patients. RE: Acupuncture there have been studies showing that it is effective for many conditions and study is ongoing through MGH at this time. I personally know many board certified acupuncturists and none of them would ever recommend that a patient stop theirwestern medical treatment.
    The anecdotes that you presented ,albeit true, were small in number and give an unbalanced view of acupuncture. Patients must look at the credentials of the therapists they are seeing and the CAM practitioners should not be advising patients re: allopathic treatment.
    I felt that your article did not present a balanced view of CAM when in reality there are many responsible and ethical CAM practitioners out there. I believe we can have the best of both worlds when CAM and allopathic medicine work together for the benefit of the patient.

    Comment by Diane Parker, RN on December 20, 2011 at 7:10 pm
  4. Dear Diane:

    I’m sorry that the blog post came across as unbalanced. This post wasn’t speaking to the issue of efficacy at all. I know that many CAM treatments are effective, and I’m aware of quite a bit of data supporting the use of acupuncture for a variety of conditions. I talk to patients about CAM often.

    The issue I was trying to address was the widespread perception that CAM treatments are intrinsically safer than allopathic treatments—and that perception is wrong.

    You’re right that my post was anecdotal. I’m an empiricist—I don’t believe anyone should believe a treatment is either safe or effective because of how it’s labeled. I want to see empiric data. Sadly, there is very little solid data on the safety and efficacy of CAM treatments. It’s also true that many allopathic treatments lack a good evidence base for safety and efficacy. My plea was for people not to assume that a treatment is safe simply because it’s labeled as CAM.

    I think my point of view may be closer to yours than you realize. You stated in your comment, “Patients must look at the credentials of the therapists they are seeing…” I agree with you, and said towards the end of this post:

    “Select a CAM practitioner carefully. Talk to your doctor, local hospital, medical school, or health department about licensure, accreditation or recommendations. Check the national association websites for a list of certified practitioners in your area.”

    I’m not telling patients not to use CAM, just to be careful and not assume it’s safe just because it’s NOT allopathic/Western medicine.

    All the best,

    Ben Kruskal

    Comment by Harvard Vanguard on December 22, 2011 at 9:14 am

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