We Are Our Brains (46 page)

Acupuncture, that exotic therapy with its impressive rituals, creates high expectations in patients and certainly has a placebo effect. The question is whether that entirely accounts for its effectiveness or whether the ancient Chinese notion of meridians and classic acupuncture points is meaningful. But studies show that determining the source of acupuncture's effectiveness can be very complex. Here are a few examples.

One study, testing the efficacy of acupuncture for migraine, arbitrarily divided patients into three groups. The first group was given genuine acupuncture, in which the needles were inserted at the classic points and the doctors had to elicit “Qi,” a radiating sensation regarded as a sign of the needle's effectiveness. The second group underwent fake acupuncture, in which the needles were inserted at predetermined non-acupuncture sites. The third group was placed on a waiting list. The treatment of the real acupuncture group didn't prove more effective than that of the fake acupuncture group, but both groups benefited more than the group on the waiting list. From this one could conclude that acupuncture is effective but that the significance of classical acupuncture points, at least in the case of migraine treatment, is debatable. However, it's impossible to say whether the benefits were achieved by a physiological mechanism or a very strong placebo effect. The same result was achieved in a similar study of three groups of patients with tension headaches.

However, in a similar experiment with patients suffering from osteoarthritis of the knee, acupuncture proved more effective. This study compared “real” acupuncture treatment with minimal acupuncture (in which needles were superficially inserted in non-acupuncture points) and a waiting list group. After eight weeks of treatment, the patients who had undergone real acupuncture showed significant improvements in terms of pain and knee function compared to the group receiving minimal treatment. Although the difference between the two groups diminished over time, a clinically relevant treatment effect was established. In the case of chronic mechanical neck pain, acupuncture proved statistically effective but clinically ineffective. In that study, electroacupuncture was compared with fake electroacupuncture (in which the treatment was identical but the needles weren't hooked up to a power supply). In the absence of a control group, the effect of the acupuncture needle itself couldn't be determined.

A brain imaging study looked at differences in brain response to acupuncture treatment, specifically at the expectations that patients suffering from painful osteoarthritis had of the treatment. In a single blind randomized crossover trial, three interventions were compared: real acupuncture, placebo acupuncture, and overt placebo acupuncture. The placebo group was treated using a Streitberger needle—a special kind of needle that, when pressed against the skin, moves back into the handle, giving the impression that it has pierced the skin. The overt placebo group knew that their treatment wasn't therapeutic, having been told that the needle wouldn't pierce the skin. None of the three treatments had the effect of reducing pain. However, scans showed that the ipsilateral insular region, which coordinates bodily autonomic reactions, was activated more by the real acupuncture needle than the Streitberger needle, although both treatments created the same expectations in patients. The two interventions caused greater activity in the prefrontal cortex, anterior cingulate cortex, and midbrain than the overt placebo treatment, of which patients had no therapeutic expectations. This experiment
shows that acupuncture needles can have a specific physiological effect and that a patient's expectations of treatment stimulate brain areas associated with reward. So acupuncture can do more than just achieve a placebo effect caused by a patient's expectations of therapy. But in order to establish acupuncture as an evidence-based form of medicine, one would need to perform similar experiments for every disorder. Animal trials can play an important role here. Painkilling in rats by means of electroacupuncture was shown to be linked to higher concentrations of vasopressin in the paraventricular nucleus, while levels of oxytocin and opioid peptides remained the same. Vasopressin can be measured in the blood, which may prove useful in evaluating the effectiveness of acupuncture and its functional mechanisms in humans.

Herbal medicine is an immensely popular form of alternative therapy. Around thirty thousand herbal products are offered for sale in the United States, and around $4 billion a year is spent on them. If you have a chronic illness and the doctors can't really help you, there comes a moment when most of us feel the need to try alternative therapy. Everyone knows someone who knows someone who was suddenly cured by it. (Curiously, no one ever mentions that diseases sometimes go away by themselves.)

An important contributing factor to the perceived success of alternative therapy is probably that alternative doctors are much nicer and make much more time for their patients than regular doctors. Belief in the effectiveness of alternative therapy, both by the practitioner and the patient, is often the best form of placebo.

People trying out herbal therapies often rationalize it by saying “There's no harm in trying.” After all, the thinking goes, these are
“natural” substances and therefore can't hurt you. This is a misconception that I would like to set right. Herbs can be completely ineffective against the maladies they allegedly cure and yet be extremely dangerous. What's more, most of the toxins we know of are also “natural” substances. That makes sense, because when a chemical substance affects our organism, it's usually through a specific protein receptor, and we have receptors only for natural substances or chemical substances resembling them.

Reading the medical literature on the possible toxic effects of “safe” herbs is enough to make your hair stand on end. A whole host of neurological and psychiatric disorders has been shown to result from the use of herbal medicine, ranging from vascular infections in the brain, swelling of the brain, delirium, coma, disorientation, hallucinations, cerebral bleeding, motor disorders, depression, muscle weakness, and tingling to epileptic seizures. Ginseng can cause insomnia, vaginal bleeding, and mania. Valerian can make you nauseous and give you a hangover. Thorn apple (
Datura stramonium
) can cause disorientation, while passionflowers can generate hallucinations. Taking kava-kava (
Piper methysticum
), sold as an antistress cure, can lead to life-threatening liver inflammation and cirrhosis of the liver, while ma huang (
Ephedra sinica
) can induce psychosis. Preparations of ma huang contain ephedra alkaloids, substances contained in diet products, pep pills, and “smart” drugs, and are also used to enhance performance in sports. These preparations have rightly been banned in the Netherlands. The ginkgo tree, which is common in China, has fan-shaped leaves that inspired Art Nouveau designs in Europe at the beginning of the twentieth century. Ginkgo is prescribed as a remedy for memory problems and dementia (it does have some effect, but even less so than Western drugs for those conditions, which are themselves not very effective) but can cause headache and dizziness. Eucalyptus can induce delirium. St. John's wort (
Hypericum perforatum
) is taken for depression and has been shown to improve mood, but it can also cause anxiety and fatigue.

Some herbs, especially Asian ones, are, moreover, polluted with
heavy metals. And don't let yourself be fooled: The argument that herbal mixtures have been used for centuries, for instance in traditional Chinese medicine, gives no guarantee whatsoever, either of effectiveness or of the absence of toxic effects. It's also important to know that herbs can interact unexpectedly and dangerously with conventional medicines. St. John's wort, for instance, can counteract oral contraceptives and disrupt the effect of antiretroviral drugs and Prozac.

Armed with this basic knowledge and a critical attitude, let us now go online. Type in “herbal therapy” on Google, and you'll get over 20 million hits for herbs against every kind of disease, along with all the rubbish spouted by the con artists who sell them. Read and tremble! Particular caution is advised when they try to sell you something that they claim has no side effects. Any medicine that works has side effects. If someone claims that a product has no side effects, there are three explanations: (1) It doesn't work, (2) its side effects have never been tested, or (3) (the most likely) both (1) and (2) apply. The only one who will certainly benefit from the herbs touted online is the herb supplier himself.

This doesn't mean that herbs can't contain chemical components that have a therapeutic effect. A great deal of work is being done in China to support traditional medicine with scientific research. Efforts are being made to identify the active chemical substances in herbs that have been used for centuries, but since TCM is based on the notion that drugs are most efficacious when there's a mixture of active substances, Chinese scientists face a daunting task. But these substances are now being isolated and their effectiveness is being researched along Western lines by means of cell cultures and animal experiments. There's considerable pressure within China itself to give TCM a scientific basis, and physicians who simply go on prescribing TCM according to ancient Chinese traditions are sharply criticized.

Sometimes the isolation of chemical substances from herbs provides some familiar results. For instance, plants that are traditionally
used against aging disorders turn out to contain a lot of melatonin. In the West, too, there are claims that melatonin is an antioxidant that inhibits the aging process, but there's no hard clinical evidence to back the claims up. However, we do know that melatonin as a purely chemical substance is effective in restoring the sleep-wake rhythm in dementia patients, reducing nocturnal restlessness, and achieving modest improvements in memory. As far as I know, no controlled trials have yet been carried out to establish the same effect using herbs containing high concentrations of melatonin. In TCM, ginseng is prescribed for problems relating to sexual dysfunction. Animal experiments in the United States have shown that ginseng indeed increases libido, facilitates erections, and stimulates sexual behavior. Now these findings only need to be confirmed in a clinical setting.

The effectiveness of traditional plant extracts is increasingly being tested in controlled clinical trials, just as in Western drug research. Sometimes the results contradict one another, as always happens in drug research. Some studies show that ginkgo leaf extract indeed causes slight improvements in older patients with memory disorders and dementia sufferers, while other studies show no improvement in memory function. A comparative analysis has been made between ginkgo and Western anti-dementia drugs (acetylcholine esterase inhibitors), which aren't very effective and have many side effects. Nevertheless, the Western drugs scored slightly better than ginkgo, so it isn't a magic bullet against dementia.

Time will reveal the reasons for the discrepancies between the studies and show who is right. The important point is that TCM is now being investigated using controlled, Western methods, so that we will eventually know whether it can indeed be used to develop effective drugs that don't have too many side effects and pose no risk of toxicity. The latter danger is far from imaginary. In 2006, samples of a TCM aloe preparation sold in Britain were found to contain 11,700 times the permitted level of mercury. It's findings like these that are currently placing extra pressure on China to modernize TCM.

It's often claimed that human beings have “free will” because we make choices. This is faulty reasoning. Every organism constantly makes choices. The point of contention is whether those choices are entirely free. The American researcher Joseph L. Price has defined free will as the ability to choose to act or refrain from action without extrinsic or intrinsic constraints. Applying this definition, can we ever be said to make a decision freely? Back in 1838 Darwin wrote that free will was a “delusion,” arguing that people rarely analyzed their motives and usually acted instinctively. Indeed, free will is such a complex issue that philosophers have yet to agree on what it actually is, though it's often said to have three components. First, an action
is only free if you could also have
abstained
from it (you must have alternative options). Second, an action must be carried out for a
reason.
Third, you should feel that you're truly carrying out the action of your own
volition.
But feelings are, of course, entirely subjective.