3D model of the molecular structure of glyphosate.
There is an ideological subculture that is motivated to blame all the perceived ills of the world on environmental factors and corporate/government malfeasance. Often this serves a deeper ideological drive, which can be anti-vaccine, extreme environmentalism, or anti-GMO. The latest environmental bogeyman making the rounds is glyphosate, which is being blamed for (you guessed it) autism.
Glyphosate is the active ingredient in the herbicide Roundup. It has been widely used for about 40 years, and with the introduction of GM crops that are Roundup resistant, its use has increased significantly in the last 20 years. It has therefore become a popular target for anti-GMO fearmongering.
Glyphosate is one of the least toxic herbicides used. It inhibits the enzyme 5-enolpyruvylshikimic acid-3-phosphate synthase which interferes with the shikimic pathway in plants, resulting in the accumulation of shikimic acid in plant tissues and ultimately plant death. The enzyme and pathway do not exist in animals, which is why toxicity is so low. Still, chemicals can have multiple effects and so toxicity needs to be directly measured and its epidemiology studied. (more…)
It’s always preferable to have objective empirical evidence to inform an opinion, rather than just subjective impressions. Confirmation bias will make it seem as if the facts support your opinion, even when they don’t. Of course, when objective evidence (such as published studies) does seem to support your position, you still have to keep your critical shields up. Confirmation bias can still kick in, resulting in cherry-picking favorable evidence, finding fault with studies whose conclusions you don’t like, and too-easily accepting those that confirm your position.
I therefore had to be careful in evaluating the following study from the BMJ, because it nicely confirms what I and many others here at SBM have been saying for years – recommendations made by TV doctors, particularly Dr. Oz, are unreliable and insufficiently based on evidence.
This was a prospective study that:
…randomly selected 40 episodes of each of The Dr Oz Show and The Doctors from early 2013 and identified and evaluated all recommendations made on each program.
Pictured: Test subjects probably not worth a press release.
A recent study addresses the problem of sensationalism in the communication of science news, an issue we deal with on a regular basis. The study was titled “The association between exaggeration in health related science news and academic press releases: retrospective observational study“. The results show two interesting things – that university press releases frequently overhype the results of studies, and that this has a dramatic effect on overall reporting about the research.
The authors reviewed “Press releases (n=462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n=668).” They found that 40% of the press releases contained exaggerated health advice, 33% overemphasized the causal connection, and 36% exaggerated the ability to extrapolate animal and cell data to humans.”
When press releases contained such exaggeration, 58%, 81%, and 86% of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17%, 18%, and 10% in news when the press releases were not exaggerated.
This study points a finger directly at academic press offices as a significant source of bad science news reporting. This does not let other links in the news chain off the hook, however. (more…)
“What’s the harm?” is an insidious idea when used as a justification for unscientific medical treatments. The argument is typically put forward with the assumption that direct physical harm is the only type of harm that can result from such treatments, so as long as they aren’t toxic there is no downside to trying them. Harm comes in many forms, however: delayed effective treatment, wasted time and energy, financial harm, the psychological harm of false hope, and the downstream effects of instilling unscientific beliefs regarding health care.
One other form of harm is physical but is not due to direct physical damage or toxicity. Rather, it is caused by CAM treatments interacting with proven therapies. A recent survey, presented at the Clinical Oncology Society of Australia annual scientific meeting, explored the potential for such interactions among oncology patients. Lead researcher Sally Brooks found that, in addition to vitamins and minerals, cancer patients were most interested in fish oil, turmeric, coenzyme Q10, milk thistle, green tea, ginger, lactobacillus, licorice, Astragalus and reishi mushrooms.
As I have written many times before, herbs are drugs, but many patients do not treat them as such because they are regulated and marketed as “supplements,” more like food than drugs. There are concerns that many vitamin and herbal products may interact with chemotherapy or radiation therapy in order to reduce effectiveness or even increase side effects. (more…)
A new study published in JAMA sheds further light on a controversial question – whether or not to prescribe low-dose aspirin (81-100mg) for the primary prevention of vascular disease (strokes and heart attacks).
Primary prevention means preventing a negative medical outcome prior to the onset of disease, in this case preventing the first heart attack or stroke. Secondary prevention refers to treatments given to patients who have already had their first heart attack or stroke in order to reduce the risk of subsequent events.
The evidence strongly supports the efficacy of aspirin for the secondary prevention of both heart attacks and strokes. Aspirin has two effects which likely contribute to this protective effect. First, aspirin is an anti-platelet agent – it reduces the stickiness of platelets, which are cell fragments in the blood that clump together to stop bleeding. They can also clump together around an ulcerated cholesterol plaque on an artery, forming a thrombus, resulting in blockage or embolus (the clot traveling downstream) and causing either a heart attack or stroke.
Other anti-platelet agents, such as clopidogrel, are also effective in preventing stroke and heart attack.
Of course, platelets exist for a reason, and blocking their action increases the risk of bleeding or can make bleeding worse when it occurs. Therefore determining the optimal dose and target population are important to maximize the benefit of aspirin or other anti-platelet agent while minimizing the bleeding risk. (more…)
Case reports are perhaps the weakest form of medical evidence. They are essentially well-documented anecdotes. They do serve a useful purpose, however. They can illuminate possible correlations, the natural course of illness and treatment, and serve as cautionary tales regarding possible mistakes, risks and complications. I say “possible” because they are useful mainly for generating hypotheses and not testing or confirming hypotheses.
Dramatic case reports, however, with objective outcomes, like death, can be very useful by themselves in pointing out a potential risk that should be avoided. For example, case reports of objective and severe adverse outcomes are often used as sufficient evidence for pulling approved drugs off the market, or at least adding black box warnings.
The chiropractic community, it seems, does not respond in a similar way to dramatic adverse events that suggest possible risk from chiropractic manipulation. A recent and unfortunate case raises once again the specter of stroke following chiropractic neck manipulation. Jeremy Youngblood was 30 years old, completely healthy, and saw his chiropractic for some neck pain. According to news reports, Jeremy suffered a stroke in his chiropractor’s office while being treated with neck manipulation for the neck pain. According to reports the chiropractor did not call 911, but instead called Jeremy’s father who had to come and pick him up and then bring him to the ER. Jeremy suffered from a major stroke and later died.
The Courage to Heal, the source of many beliefs about false memory syndrome
It is disheartening that we have to return to pseudosciences that have been debunked decades ago, because they continue to linger despite being eviscerated by scientific scrutiny. Belief systems and myths have incredible cultural inertia, and they are difficult to eradicate completely. That is why belief in astrology, while in the minority, persists.
Professions, however, should be different. A healing profession should be held to a certain minimum standard of care, and that standard should be based upon something real, which means that scientific evidence needs to be brought to bear. Professionals are not excused for persisting in false beliefs that have long been discredited.
The 1980s saw the peak of an idea that was never based on science, the notion that people can suppress memories of traumatic events, and those repressed memories can manifest as seemingly unconnected mental health issues, such as anxiety or eating disorders. The idea was popularized mostly by the book The Courage to Heal (the 20th anniversary edition was published in 2008), in which the authors took the position that clients, especially women, who have any problem should be encouraged to recover memories of abuse, and if such memories can be dredged up, they are real.
One of the most interesting aspects of living through the second half of the 20th century and into the first half of the 21st century is the profound change in access to information. I remember in the 1980s there was a buzz (at least among technophiles and science fiction nerds) about how computers were going to be connected in a worldwide network and it would transform the way we access information and communicate. The reality we are living in now exceeds even the most fevered predictions being made at that time.
What was difficult to anticipate was how rapid access to almost any information would affect our day-to-day lives. Now, during a discussion, if a fact is in dispute we can simply look it up and resolve the dispute. I can no longer imagine doing research in a pre-internet age, promoting science-based medicine without social media, or collaborating without the virtual-time communication of e-mail.
The internet is rapidly becoming humanity’s collective culture and body of knowledge. For that reason it is important to nurture that body of knowledge to ensure that it is complete, accurate, and fair. That goal is frustrated, however, by the fact that the World Wide Web is not simply being used for scholarly information. It is also a tool to promote ideology and commercial interests. Therefore any efforts to provide scientifically accurate and unbiased information are likely to be swamped by well-funded and highly-motivated misinformation. Search on any medical topic and you will quickly see what I mean.
In the tradition of James Randi, a Chinese doctor who is an outspoken critic of Traditional Chinese Medicine (TCM) has issued a challenge to its proponents. He has put up 50,000 yuan (about $8,000), which has been matched by donors for a total of over 100,000 yuan, to any TCM practitioner who can use pulse diagnosis to determine with accuracy whether females subjects are pregnant.
Ah Bao is the blogging pseudonym of a burn-care doctor at Beijing Jishuitan hospital. He is trained in scientific medicine and has criticized his country for clinging to pre-scientific philosophy-based health care. He calls TCM “fake science” and now wants to demonstrate that the claims of TCM practitioners are without factual basis.
His challenge is a good one because it focuses on a clear criterion. Subjects will either be pregnant or not pregnant, and the TCM practitioner, using only pulse analysis and blinded to the patient themselves, must determine with an 80% accuracy which subjects are pregnant. A TCM practitioner, Zhen Yang, has taken him up on the challenge and they are now working out the details. (more…)
On the home page of Zhu’s Neuro-Acupuncture Center there is a video relaying a testimonial of how scalp acupuncture helped a patient recover from acute stroke. The use of testimonials is very common in the promotion of dubious health treatments. A personal story and endorsement is psychologically more compelling than dry data. Testimonials are completely unreliable, however, and in fact I would argue that they are ethically questionable. I would even go as far as saying that the presence of testimonials is almost a sure sign that the treatment being promoted is not legitimate.
Webpage screenshot (click picture to embiggen)
What I could not find on Zhu’s website were links to published scientific researcher establishing the safety and efficacy of his treatments. You would think if they existed, he would display them prominently.
Acupuncture for stroke is a common claim, contradicting the notion that acupuncture is primarily used for the symptomatic treatment of subjective symptoms. That, in my experience, is part of the promotional strategy for many CAM treatments. They are presented as benign treatments for symptomatic treatment only, so what’s the possible harm. In reality, proponents will claim they can actually treat diseases whenever given the chance.