The question of whether or not there is a link between the use of mobile phones (also called cell phones) and the risk of brain tumors has been cropping up more and more frequently in the media – every time a new study or analysis comes out. This is a very important question of public health as cell phone use is becoming more common, and brain tumors are a very serious and often life-threatening category of diseases.
Of course such questions are best answered by a dispassionate, careful, and systematic look at the science – what is the plausibility of a link and what is the evidence that there actually is one. At this point we are somewhere in the middle of studying this problem. We already have substantial data, but it is conflicting and the research community is still debating on how to get more definitive data everyone can agree upon. So at present there is a variety of opinions on the matter. The consensus seems to be that cell phones probably do not cause brain tumors, but we’re not sure, there is meaningful dissent from this opinion, and so more study is needed.
There are two types of scientific studies we can do to answer this question. The first is biological and looks at the effects of radiation, and specifically the type and strength of radiation emitted by cell phones, on cells in a test tube and on animals. This will tell us if a risk from cell phones is plausible, if there is a mechanism, and what, if any, the effects are likely to be. But this kind of data will not tell us if cell phones in fact have caused or are causing brain tumors.
The story of Airborne – a popular supplement marketed as an “herbal health formula that boosts your immune system to help your body combat germs” – is representative of what is wrong with the supplement industry and how it is regulated in the US. Recently the company that sells Airborne – Airborne Health, Inc – agreed to pay $23.3 million to refund consumers who purchased the product (if they have proof of purchase). This was to settle a class-action law suit brought by the Center for Science in the Public Interest (CSPI) and others claiming false advertising. In the settlement the company did not admit any wrongdoing. While this can be viewed as a minor victory for science-based medicine, it actually highlights the many deficiencies in the system.
For background, Airborne was launched in 1999 as a supplement designed to ward off the common cold. It has been extremely successful, due largely to its slick packaging, a clever slogan that it was developed by a school teacher, and promotion by Oprah Winfrey. The Airborne brand of products has expanded, including pixie powder for children, Airborne seasonal, Airborne Jr., Airborne on-the-go, and others. Advertising urged users to take Airborne at the first sign of a cold or as a preventive treatment if about to enter a germ-filled area, like an airplane. They also cited a “scientific” study that demonstrated Airborne is effective.
At the end of the 18th and beginning of the 19th century electricity and magnetism were cutting edge science, full of excitement and unknown potential. Capitalizing on this excitement, Franz Anton Mesmer captured the imagination of the European intelligentsia with his bogus claims of animal magnetism. At the turning of the next century radioactivity was the new and fascinating scientific discovery, and this lead to a market for radioactive tonics good for a multitude of complaints, or just for extra energy. A few decades later radio waves were the latest healing craze.
Cutting edge science is cool and exciting, it evokes the promise of the future and the public has learned to expect that the latest gee whiz science appears like magic. Its newness also virtually guarantees that the public at large will mostly not understand the science or its true implications. This is a situation ripe for exploitation.
Today one medical technology that does possess great promise but is not yet ready for prime time is stem cell therapy. Legitimate scientists involved in stem cell research are almost giddy about the possibilities. Early applications are possibly just around the corner, and only time will tell what the full potential of this technology is. But right now there are no legitimate stem cell therapies outside of research protocols. It is therefore not surprising that the con artists of today are exploiting the tremendous hype of stem cells.
A recent meta-analysis of the most commonly prescribed antidepressant drugs raises some very important questions for science-based medicine. The study: Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug Administration, was conducted by Irving Kirsch and colleagues, who reviewed clinical trials of six antidepressants (fluoxetine, venlafaxine, nefazodone, paroxetine, sertraline, and citalopram). They looked at all studies submitted to the FDA prior to approval, whether published or unpublished. They found:
Drug–placebo differences in antidepressant efficacy increase as a function of baseline severity, but are relatively small even for severely depressed patients. The relationship between initial severity and antidepressant efficacy is attributable to decreased responsiveness to placebo among very severely depressed patients, rather than to increased responsiveness to medication.
The press has largely reported this study as showing that “antidepressants don’t work” but the full story is more complex. This analysis certainly has important implications for how we should view the body of evidence for these antidepressants. It also illuminates the possible role of publication bias in the body of scientific literature – something that has far ranging implications for science-based medicine.
One of the most successful propaganda campaigns within health care in the last few decades has been the re-branding of nutrition as “alternative” or out of the mainstream of scientific medicine. I have marveled at how successful this campaign has been, despite all the historical evidence to the contrary. I suppose this is partly a manifestation of the public’s short-term memory, but it also seems to reflect basic psychology.
There is evidence that most ancient cultures recognized the importance of diet in health. The Greeks recognized both the benefits of a varied diet and the negative health consequences of obesity, for example. But knowledge of nutrition was limited to these broad observations and was mixed with superstition and cultural beliefs.
The science of nutrition probably dates back to 1614 when scurvy (the disease that results from vitamin C deficiency) was first recognized as a dietary deficiency, one that could be cured by eating fresh fruits and vegetables. In 1747 Lind conducted what might be the first clinical trial – systematically comparing various diets for the treatment of scurvy and finding that citrus fruits were the key to treatment.
South Africa’s Health Minister, Manto Tshabalala-Msimang, is fighting to protect the traditional healers of her country from having their methods tested scientifically. She warns that, “We cannot use Western models of protocols for research and development,” and that she does not want the incorporation of traditional healing to get “bogged down in clinical trials.” Her arguments are anti-scientific and represent a health tragedy for South Africa. However, such attitudes are not uncommon within the community of sectarian medicine and represent some of the common rhetoric used to disguise anti-scientific positions.
This is also not the first controversial statement made by South Africa’s health minister. In 2006 she advocated using garlic and beetroot to treat HIV infection, prompting outrage from South Africa’s academic community. In response to criticism about delays and funding cuts in providing anti-retroviral drugs to HIV sufferers in South Africa, the Health Minister said, “Garlic is absolutely critical, we need to do research on it. We cannot just ridicule it.” South Africa’s president, Thabo Mbeki, resisted calls for Ms. Tshabalala-Msimang’s resignation.
The Food and Drug Administration (FDA) is proposing a very interesting loosening of their regulations of pharmaceutical company marketing. The pros and cons of the proposed changes present an interesting dilemma, with legitimate points on both sides.
When the FDA approves a drug it is approved for a very specific medical indication. I have long thought that FDA approved indications for drugs were too narrow and restricting. For example, most anti-seizure medications are initially approved not for seizures but only for certain types of seizures – for example for adjunctive therapy (meaning it is meant to be added to another drug rather than used alone) for focal onset seizures (and not against primary generalized seizures – or ones that begin all over the brain at once).
Once approved physicians are free to use drugs as they see fit. If evidence shows that a new seizure medication is effective as first line treatment, then it is ethical good medicine to use it that way, even if it is not FDA approved for that use (this is called off-label use). FDA approved is not equivalent to science-based.
The core principle of science-based medicine is that health care decisions should be based upon our best current scientific evidence and understanding. When applied to the regulation of health products this means that health claims should first be required to meet some reasonable threshold of scientific evidence before they are allowed. Admittedly this is not a purely scientific question but the application of scientific knowledge to an essentially political question – the balance of protection vs freedom.
Regardless of where one thinks this balance should be, I think most would agree that is it a problem if the public generally wants more protection than it is getting, or believes it is currently getting more protection than it is. A Harris poll from 2002 indicates that the majority of Americans believe that companies cannot make health claims about supplements unless they have been proven scientifically and approved by the FDA, when in fact this is not the case. The Dietary Supplement Health and Education Act of 1994 (DSHEA), largely through the efforts of Senator Orin Hatch from Utah, removed supplements from the control of the FDA and specifically allowed for so-called structure function claims to be made about products without any burden of proof. Most Americans are not aware of this fact.
A new study by lead author Shelly Gray and published in the latest issue of the Journal for the American Geriatric Society, found no effect from taking Vitamin C or E, either alone or in combination, on the risk of dementia or Alzheimer’s disease after 5.5 years. Vitamins C and E were chosen because they both have significant antioxidant activity, and so this study was partly to test the hypothesis that oxidative stress causes or contributes to dementia.
The science behind the role of oxidative stress in aging and neurodegenerative disorders and the modulation of oxidative stress by nutritional antioxidants is complex and has not yielded many confident therapeutic recommendations. And yet, by contrast, antioxidants are sold to the public with dramatic health claims as if they were well established. It is common for marketing hype to out pace scientific reality, especially when the science is complex and preliminary so that there is as yet no firm scientific consensus.
For background, oxidative stress refers to the production in the cells of the body of certain oxygen-based compounds, collectively called reactive oxygen species (ROS), that are highly reactive. Some of these compounds are simply waste products of cell metabolism. Others serve a useful purpose, such as nitric oxide that is used in neurotransmission. What these ROS compounds have in common is that they react with proteins, DNA, and other cell components and cause damage.
While attending a lecture by a naturopath at my institution I had the opportunity to ask the following question: given the extreme scientific implausibility of homeopathy, and the overall negative clinical evidence, why do you continue to prescribe homeopathic remedies? The answer, as much as my question, exposed a core difference between scientific and sectarian health care providers. She said, “Because I have seen it work in my practice.”
There it is. She and many other practitioners of dubious modalities are compelled by anecdotal experience while I am not.
An anecdote is a story – in the context of medicine it often relates to an individual’s experience with their disease or symptoms and their efforts to treat it. People generally find anecdotes highly compelling, while scientists are deeply suspicious of anecdotes. We are fond of saying that the plural of anecdote is anecdotes, not data. Why is this?