Dr. Oz takes a big bite of bad science

Mehmet Oz hosts a popular TV show that reaches millions of people.  He offers a constant stream of medical advice, and he is popular because he makes his topics sound dramatic, or exciting, or surprising, or all three.

Unfortunately, Dr. Oz sometimes has a poor understanding of science.  At least I hope so, because he promotes so many outrageous treatments, with such enthusiasm, that the only other explanation I can think of is that he is simply a fraud. I don't think that's true, so let's give him the benefit of the doubt and assume that when he makes a mistake, he is simply ignorant of the truth.  His latest startling revelation is that the metal fillings in your teeth are very, very bad for you.  Or are they?

Last week, Dr. Oz hosted a show called "Toxic Teeth: Are Mercury Fillings Making you Sick?  The show looked at silver amalgam fillings, which contain a small amount of mercury chemically bound within them.  Mercury is indeed a toxin.  Should you worry?  

One problem with taking a skeptical look at a Dr. Oz show is that he packs each episode with scientific claims, coming at you thick and fast, and it would take hours to critique them all.  Instead, I'll just pick a few, which illustrate Oz's lack of concern for accuracy, and his apparent ignorance of the underlying science about dental fillings.

Dr. Oz opens his show with a dramatic claim about mercury: 

"This thermometer contains mercury," he says, holding up a very small thermometer. "If I were to drop it, we would have to evacuate this entire studio immediately!" 

Now, this is complete nonsense.  If you drop a mercury thermometer, you should carefully clean up the mercury, which beads up into nice little silver-colored balls.  No one in the room is in danger, unless perhaps they try to drink it.*

This opening salvo should set off anyone's skeptical alarm bells.  Here's a guy who doesn't seem to mind exaggerating to make a point.  Why trust anything he says in the rest of the show?  I suspect, though, that after watching this episode, thousands of Oz's loyal viewers raced to the phone and made appointments to have the silver fillings in their teeth removed.

Dr. Oz continues his introduction by explaining that mercury is contained in silver tooth fillings.  No one knew, he claims, that mercury vapor could be released from these fillings, but this news:

"sparked a firestorm 30 years ago [here the show cuts to a graphic of a fireball exploding] when major news reports brought to light the potential TOXICITY of mercury fillings.  ... Now there's mounting new evidence showing mercury is released when you eat, and even when you brush your teeth."

Quick, run to the dentist!  Get this toxic mess out of my mouth!  

But hang on a minute.  Why aren't people dropping like flies from the fillings in their teeth?  With little effort, I determined that, contrary to Dr. Oz's statements, nothing new has been discovered lately about silver tooth fillings.  I found studies going back to the 1970s that shown that we've long known for decades that mercury is released from these fillings. But Oz ignores all these.  He even announces, a few minutes into the show, that 

"for the first time ever, I'm going to show you what happens when you brush your teeth with mercury fillings."  

No, this is not the "first time ever."  As a scientist, I find it worrisome that Oz seems quite comfortable claiming, incorrectly, that he's the first person ever to tell the world about this.

Perhaps the most outrageous - and unintentionally funny - segment of the show is the "demonstration," where Oz introduces an Oz-certified expert on mercury vapor, David Wentz, who has a gizmo that looks like it was built by a sideshow huckster.  The device is a plexiglass box that looks like it was meant to handle biohazards, with black rubber gloves that let you manipulate its contents.  In the box: a set of fake teeth containing... silver fillings!  And a toothbrush!  

As he walks over to the device, Oz says "I work with Dave Wentz and his Ph.D. dad."  This goes by really fast, so you would be excused for not realizing that Dave Wentz himself doesn't have a Ph.D., and for not knowing whether he has any credentials at all.  Dr. Oz conveniently omits the fact that Wentz and his father run a highly profitable nutritional supplements company, USANA http://www.usana.com/dotCom/about/index, which happens also to donate money to Oz's nonprofit corporation, HealthCorps.  Hmm.

Dr. Oz then reaches into the box, and while the audience watches in hushed excitement, he brushes the teeth, right on top of those silver fillings!  Right on cue, Wentz proclaims that the mercury vapor reading hits 61 in just a few seconds. 

"Anything over zero is toxic," Wentz proclaims.  "And we're at 61."
"Oh my goodness, 61!" Dr. Oz exclaims.
"That mercury is coming off the fillings, into your mouth, going across the blood-brain barrier, into your brain," says Wentz dramatically.

Wow.  I've been brushing my teeth (which have several fillings) for years.  How can I not be dead?

As Dr. Oz should know, "the dose makes the poison."  Even water can kill you if you drink too much of it.   Wentz is clearly wrong to say that "anything over zero is toxic."  

How much mercury is safe, then?  

According to the EPA, 0.1 micrograms of mercury per kilogram of body weight per day is safe.  For an adult who weighs around 150 pounds, that's about 7 micrograms.  A 6-ounce can of tuna has about 20 micrograms of mercury, about 3 times the safe amount per day.  Scientists do have real concerns that mercury in tuna and other fatty fish might present a health hazard.   

Dr. Oz's device seemed to show that 61 micrograms of mercury were released from brushing teeth, which would be about 9 times the exposure that is considered safe.  Is there really a risk here?

Well, no.  The EPA has found that "nearly all methylmercury exposures in the U.S. occur through eating fish and shellfish."  (Admittedly, though, this is not mercury vapor.) The precise question that Oz claims to be explaining "for the first time" has been examined in multiple studies, and the evidence is that silver fillings are harmless.  (See the FDA summary here.)  

A thorough scientific review in 2004 concluded that:

"The current data are insufficient to support an association between mercury release from dental amalgam and the various complaints that have been attributed to this restoration material. ... Individuals with dental amalgam-attributed complaints had neither elevated HgU nor increased prevalence of hypersensitivity to dental amalgam or mercury when compared with controls. The findings of these studies suggested that individuals with complaints self-attributed to dental amalgam should be screened for underlying dental, physical, and psychiatric conditions."

So no, there's no evidence that mercury from silver fillings causes any health problems.  None.

But what about that device on Dr. Oz's show, which showed 61 micrograms being released in just a few seconds of brushing the teeth?  My conclusion is that the device in Dr. Oz's studio was either wildly inaccurate or simply fraudulent.  The setup was almost a parody of what real scientific instruments look like, and nothing about it gave me any confidence that it was reliable.  I would suggest to Oz that before making a claim like this, he should ask rigorously trained scientists to make the measurements using properly calibrated equipment.  A TV studio is no substitute for a real lab. 

But wait: Mehmet Oz is a Professor of Surgery at Columbia University - he must know his science!  Plus he has an M.D. from the University of Pennsylvania, and he did his undergrad studies at Harvard.  By all appearances, he is a very smart guy.  If his show were about heart surgery - his specialty - it would no doubt be professional, accurate, and probably far too technical to attract an audience.

Here's the rub: despite his credentials, Oz is not an expert on mercury amalgam fillings.  He probably could have read and understood the science, but he appears to be unaware, or too busy to  be bothered by, the many scientific studies on this subject. Had he done his homework, he might not have presented such a spectacularly overblown episode that seems intended to scare people into removing the silver fillings from their teeth.  

So there's no need to go out and get your silver fillings replaced.  It's too bad that a highly educated surgeon like Mehmet Oz, with such a big audience, prefers to present wild exaggerations rather than telling people the truth.  Perhaps, though, the truth just isn't that exciting.

*Note added on followup: Even swallowing is rarely harmful.  From J. Dodes: "Acute toxic exposures to  elemental mercury are rare but there have been cases of elemental mercury being accidentally released directly into the  bloodstream from broken rectal thermometers and when elemental mercury had been swallowed intentionally in an attempt at suicide.  In all these cases there was no long-term effects from the mercury."  Dodes, JE.  The Amalgam Controversy:an evidence-based analysis.  JADA, 132:348-56, 2001.

Congress holds an anti-vaccine hearing

I was in my car yesterday listening to C-SPAN (yes, I do that sometimes), when to my stunned surprise I heard Congressman Dan Burton launch into a diatribe on how mercury in vaccines causes autism.  No, this was not a replay of a recording from a decade ago.  The hearing was held just a few days ago by the Committee on Oversight and Government Reform.

Congressman Burton used this hearing to rehash a series of some of the most thoroughly discredited anti-vaccine positions of the past decade.  Burton is a firm believer in the myth that vaccines cause autism, and he arrogantly holds the position that he knows the truth better than the thousands of scientists who have spent much of the past decade doing real science that proves him wrong.  

In a classic political move, the committee called on scientists Alan Guttmacher from the NIH and Colleen Boyle from the CDC to testify, but in fact the committee just wanted to bully the scientists.  Committee members lectured the scientists, throwing out bad science claims, often disguised as questions, thick and fast.  Alas, Guttmacher and Boyle weren't prepared for this kind of rapid-fire assault by pseudoscience.

Burton himself was the worst offender, offering anecdotes and bad science with an air of authority.  He stated bluntly: 

“I’m convinced that the mercury in vaccinations is a contributing factor to neurological diseases such as autism."

No, it isn't.  Dozens of studies, involving hundreds of thousands of children, have found the same thing: there is no link whatsoever between thimerosal and autism, or between vaccines and autism.  And Burton went off the deep end with this: 

"It wasn’t so bad when a child gets one or two or three vaccines… Mercury accumulates in the brain until it has to be chelated.” 

Bang bang, two false claims in 10 seconds.  First he claims that mercury from vaccines "accumulates in the brain", a statement with no scientific support at all. Then he claims that chelation therapy is the solution - a radical, potentially very harmful treatment that no sensible parent would ever force on their child.  Unfortunately, some quack doctors have experimented with chelation therapy on autistic children, despite that fact that it can cause deadly liver and kidney damage, and one of them caused the death of a 5-year-old boy in 2005.

Burton also claimed that single-shot vials would "eliminate the possibilty of neurological damage from vaccines" - a claim that was invented out of thin air by the discredited anti-vax doctor Andrew Wakefield, whose fraudulent 1998 study was the spark that started the current wave of anti-vax hysteria.

Congressman Bill Posey from Florida was just as bad as Burton, demanding a study of vaccinated versus unvaccinated children, a standard talking point of the anti-vax movement.  (Congressman Posey: do you even realize that your question is almost identical to what Jenny McCarthy asked five years ago, on the Larry King Live show?)  Here's his question to the CDC's Boyle:

"I wonder if the CDC has conducted or facilitated a study comparing vaccinated children with unvaccinated children yet - have you done that?"

Dr. Boyle wasn't prepared for this.  She tried to point out that many studies have been done looking at the relation between vaccines and autism, but she didn't get very far before interrupted, thus: 

Rep. Posey: “So clearly, definitely, unequivocally, you have studied vaccinated versus unvaccinated?” 

Dr. Boyle: “We have not studied vaccinated versus unvaccinated." 

Posey: “Never mind. Stop there. That was the meaning of my question. You wasted two minutes of my time."

Dr. Boyle simply wasn't prepared for a Congressman who was parroting anti-vax activists.  It's too late now, but her response should have been this:

Congressman Posey, only an extremely unethical scientist would consider conducting such a study.  To compare vaccinated versus unvaccinated children in the manner you suggest, one would have to withhold vaccines from young children.  We know from decades of evidence, involving tens of millions of children, that vaccines save lives.  Few if any medical interventions are more effective than vaccines. 

But Congressman, the scientific community has done observational studies of vaccinated versus unvaccinated children, comparing autism rates in children whose parents chose not to vaccinate.  Those studies show that autism rates were slightly higher in unvaccinated children.  That's right, vaccinated children had autism at a lower rate. 

So no, Congressman Posey, the CDC hasn't done a study of vaccinated versus unvaccinated children.  Only a corrupt dictatorship could impose a study like that on its people.  Is that what you want?

To make matters worse, the House committee invited Mark Blaxill to testify.  Blaxill is a well-known anti-vaccine activist whose organization, SafeMinds, seems to revolve around the bogus claim that mercury in vaccines causes autism.  His organization urges parents not to vaccinate their children, and giving him such a prominent platform only serves to spread misinformation among parents of young children.  

Blaxill's central claim is that that we're in the midst of an autism epidemic: 

"For a long time, reported U.S. autism rates were low, estimated at about 1 in 10,000. Then around 1990 something new and terrible happened to a generation of children. Autism rates didn’t just rise, they multiplied," claimed Blaxill in his written testimony.

His entire argument builds on this.  Yet multiple studies, looking carefully and objectively at the data, indicate that all or nearly all of the rise in autism cases is due to increasing diagnoses, which in turn is due to multiple factors: a dramatically broading of the definition of autism in the early 1990s, a greater awareness of the condition, and a greater willingness of doctors and parents to accept the diagnosis.  For an objective summary of the evidence, see the articles by neurologist Steven Novella here and here, which summarize a dozen epidemiological studies.  The weight of the evidence shows that the actual incidence of autism is either stable or possibly rising very slowly.  There is no "autism epidemic."

It's also worth pointing out that Blaxill is a conspiracy theorist who claims that the "CDC has actively covered up the evidence surrounding autism’s environmental causes."  

Congress has every right to conduct oversight into medical research at the NIH and the CDC.  But when Dan Burton, Bob Posey, and others decide in advance what the science says, and abuse their power to demand "answers" that validate their badly mistaken beliefs, people can be harmed. Over the past decade, the anti-vaccine movement has successfully convinced millions of parents to leave their kids unvaccinated, and the result has been serious outbreaks of whooping cough, haemophilus, measles, chicken pox, and mumps around the U.S. and Europe.  

Some anti-vax parents claim that these childhood illnesses aren't so bad.  I wish they would talk to the parents of young children who have died in recent whooping cough outbreaks.  These illnesses can be deadly.

Message to Congress: science isn't easy, and autism is complicated.  Don't criticize science when it doesn't give you the answer you thought you knew.  That's not how science works.  Thousands of scientists are now trying to identify the causes of autism, and they've made progress, especially on the genetic front.  The answer might not be simple, but we will find it.  

Another hero of the anti-vaccine movement bites the dust

I often wonder what motivates anti-vaccinationists. Are they in it because they truly believe they are offering valid treatments and advice? (Some of them do, I think.) Or are they just in it for baser reasons, such as money and fame?

Boyd Haley is a retired professor of chemistry from the University of Kentucky. His name has appeared several times in the Comments sections of this blog (for example, here and here), when commenters have presented him as a scientific expert supporting the claim that thimerosal in vaccines causes autism.

In his own words, Haley has said

“I have been a strong proponent of investigating thimerosal as the casual agent for autism spectrum disorders based on the biological science that shows thimerosal to be incredibly toxic, especially to infants.”

Haley also wrote

“If, indeed, the complete removal of thimerosal from vaccines was not followed in an appropriate time by a decrease in autism then this would be solid proof that thimerosal was not causal for autism.”

Thimerosal was removed from childhood vaccines in the U.S. by 2002, and the rate of autism diagnoses continued to increase, but Haley simply changed his tune and continued to claim that thimerosal causes autism. The overwhelming (and still growing) evidence against the thimerosal-autism link has apparently done nothing to change his mind.

Is Haley simply a confused chemist who fails to understand epidemiological evidence? Or does he have another agenda?

Well, he does: money.

As Los Angeles Times reporter Trine Tsouderos wrote in a two-part story this past week, Haley and his company have been marketing a chelating agent – a powerful, highly toxic chemical that removes mercury from the bloodstream – as a treatment for autism. They also claim that this chemical, called OSR#1, is a harmless dietary supplement. Haley’s company, CTI Science, is selling OSR#1 as "a toxicity free, lipid soluble antioxidant dietary supplement." The LA Times ordered 30 100-milligram capsules of OSR#1 for $60 through an online pharmacy.

The FDA has sent Haley and his company a formal warning letter telling them to stop marketing this unapproved drug as a supplement. Haley’s claim that OSR#1 is a supplement is a flimsy attempt to try to avoid regulation of this dangerous chemical as a drug, though it clearly is a drug. (Dietary supplements are unregulated in the U.S. - a topic for another day.) The FDA letter is unambiguous, stating:

“this product is a new drug, as defined by section 201(p) of the Act, 21 U.S.C. § 321(p), because it is not generally recognized as safe and effective for use under the conditions prescribed, recommended, or suggested in its labeling.”

Just to be sure, I checked the CTI website today, and the main headline is “CTI Science Introduces OSR#1.” Haley is President and CEO of the company and his former University of Kentucky holds a patent on it. There are no clinical trials or other data showing that OSR#1 is safe or effective; on the contrary, the FDA letter explains that it has several serious side effects, including diarrhea, abnormalities of the pancreas, and lymphoid hyperplasia.

This hasn’t stopped Boyd Haley and his company from marketing their drug as a treatment for autism. The anti-vaccination site Age of Autism has promoted it; indeed, the LA Times reported that

[AoA’s] managing editor, Kim Stagliano wrote of sprinkling the white powder on her three daughters' breakfast sandwiches and orange juice. "We've seen some nice 'Wows!' from OSR," she wrote.

Boyd Haley may be misguided, but he has a deep financial reason for pushing the link between thimerosal and autism: without it, his company can’t sell its product.

Will the anti-vaccinationists start to doubt Dr. Haley? Will his obvious conflict of interest, and his violation of FDA regulations, make them wonder why he’s selling them a powerful, possibly harmful chelating agent to treat their children? I hope so.

For further reading, I recommend the recent articles by Dr. Steven Novella at Neurologica and Orac’s detailed discussion at Respectful Insolence.

Vaccine court ruling: thimerosal does not cause autism

Does thimerosal, a preservative used in some vaccines, cause autism?

Thimerosal is a mercury-containing compound that has been used since the 1930s as a preservative in vaccines. Why was thimerosal introduced into vaccines? Well, early vaccines were administered from multi-dose bottles, in which bacteria could grow. In one particularly disastrous incident in 1928, 12 children in Australia died from staph infections after getting the diptheria vaccine from the same multi-dose bottle. After the introduction of thimerosal, bacterial infections caused by vaccination virtually disappeared.

Fast-forward 70 years, to the modern anti-vaccination movement. Following the late 1990s, a small number of activists, led in more recent years by J.B. Handley (who founded Generation Rescue in 2005) and a few others, decided that the mercury in vaccines causes autism. Robert F. Kennedy Jr. wrote articles promoting his crackpot notion of a large government conspiracy to cover up the harm being caused by thimerosal. The movement took off, especially after former Playboy model Jenny McCarthy became the “face” of Generation Rescue.

Was there every any scientific support for the link between thimerosal and autism? From the late 1990s to the present, scientists have looked closely at the evidence, and every well-done study has pointed to the same conclusion: thimerosal in vaccines has no link to autism. In one very large Danish study, autism rates rose after thimerosal was removed from vaccines. Another study looking at California, Sweden, and Denmark found the same thing. These results directly contradict the claim that thimerosal causes autism.

Despite the lack of evidence, the anti-vaxers have continued to wage their war against vaccines on two fronts. Last month, they lost the final battle in one effort, which claimed that the measles-mumps-rubella (MMR) vaccine causes autism. That battle started with the now-discredited 1998 study published in The Lancet by Andrew Wakefield. After the British General Medical Council ruled that Wakefield acted “dishonestly and irresponsibly”, the Lancet formally retracted the original paper, and a few days later Wakefield was forced to resign from the institute he founded in the U.S. to promote his claims.

Thimerosal was the “second front” in the anti-vax war, and now they’ve lost this one too. Last Friday, a special vaccine court ruled on three cases in which parents were suing on behalf of their autistic children. In each case, the parents claimed that thimerosal had caused their child’s autism. In each case, the Special Master (a judge) ruled definitively against the parents. The result was a slam-dunk win for science.

The three rulings take up over 600 pages, far too much to summarize, so I’ll just excerpt briefly from two of the conclusions. Special Master Denise Vowell, in the Dwyer case, issued a particularly devastating decision, ruling that claims about mercury were completely implausible and that the parents’ notion of “regressive autism” had no basis in science:

Petitioners propose effects from mercury … that do not resemble mercury’s known effects on the brain, either behaviorally or at the cellular level. To prevail, they must show that the exquisitely small amounts of mercury in TCVs [thimerosal-containing vaccines] that reach the brain can produce devastating effects that far larger amounts experienced prenatally or postnatally from other sources do not. … In an effort to render irrelevant the numerous epidemiological studies of ASD [autism spectrum disorder] and TCVs that show no connection between the two, they contend that their children have a form of ASD involving regression that differs from all other forms biologically and behaviorally. World-class experts in the field testified that the distinctions they drew between forms of ASD were artificial, and that they had never heard of the “clearly regressive” form of autism about which petitioners’ epidemiologist testified. Finally, the causal mechanism petitioners proposed would produce, not ASD, but neuronal death, and eventually patient death as well. The witnesses setting forth this improbable sequence of cause and effect were outclassed in every respect by the impressive assembly of true experts in their respective fields who testified on behalf of respondent.

It’s interesting that Vowell found that even if the “exquisitely small” amounts of mercury in vaccines had an effect, they wouldn’t cause autism. It was also somewhat sad to see how a well-known statistician, UCLA professor Sander Greenland, appearing in support of the thimerosal-autism link, embarrassed himself by presenting testimony that “largely represented an opinion based on a set of assumptions,” according to the ruling. Greenland’s arguments relied entirely on the existence of “clearly regressive autism,” but the Special Master pointed out that Greenland “was not qualified to opine on its existence.” Ouch.

And here is an excerpt from the 122-page decision of Special Master George Hastings in the King case:

...the evidence is overwhelmingly contrary to the petitioners’ contentions. The expert witnesses presented by the respondent were far better qualified, far more experienced, and far more persuasive than the petitioners’ experts, concerning the key points. The numerous medical studies concerning the issue of whether thimerosal causes autism, performed by medical scientists worldwide, have come down strongly against the petitioners’ contentions. Considering all of the evidence, I find that the petitioners have failed to demonstrate that thimerosal-containing vaccines can contribute to the causation of autism.”

I’m not optimistic that these clear, decisive rulings will have any effect on the conspiracy theorists in the anti-vax movement. Indeed, over at Age of Autism, they’ve already posted an article titled “Special Masters Protect Vaccine Program and Deny Justice to Vaccine-Injured Children.” The article, which is a combination of denialism and conspiracy mongering, claims that the trials ignored the science in order to defend the government’s vaccine program.

On the contrary, scientists studying autism want nothing more than to understand its cause and eventually to produce effective treatments. A growing body of evidence points to genetic factors behind ASD, but it will take much more work to pin down the complex combinations of genes that cause the various behaviors now called autism spectrum disorder. For example, a recent (2007) study by Sebat et al. found a clear link between ASD and de novo copy number variation (de novo mutations are those that arise for the first time in the children). We need more studies like this one if we’re to figure out this disease.

After the ruling, Alison Singer of the Autism Science Foundation said “It's time to move forward and look for the real causes of autism.” Well said. I hope that some in the anti-vax movement will recognize that if they truly want to find a cure for autism, they will support the science instead of insisting, as they do now, that more effort be poured into research on discredited hypotheses. The thimerosal-autism hypothesis is dead.

Mercola's bogus homeopathy treatments for the flu

I've just read Dr. Mercola's latest flu remedies, and I'm feeling scornful. I'm sorry, but Mercola is such an outrageous quack that he just leaves me astonished.
His latest "reliable and safe" treatments, posted just yesterday, are a set of homeopathic remedies for the flu. When I saw the headline, I couldn't wait to read on: one of my favorite quacks, endorsing the most laughable of all quack remedies - how delightful!

It's a short article, and almost every line is wrong. Given Mercola's recent scare-mongering about the flu vaccine, which I wrote about a few months ago, I'm not surprised that he continues to push his own "natural" cures - that's how he makes money, selling ineffective treatments after making bogus claims about them. Let's look at how he says we should treat our flu symptoms.