Supreme Court bungles the science in DNA patent decision

[This is slightly modified from my post 2 days ago at Forbes.]

The Supreme Court ruled this week that Myriad Genetics doesn't own your DNA after all.  Myriad holds patents on the BRCA1 and BRCA2 genes, which are linked to an increased risk of breast and ovarian cancer, and they charge exorbitant fees for their DNA diagnostic test of those genes.  As I've written before (such as this 2012 Clinical Pharmacology article), Myriad didn't invent the genes, and the patents should not have been granted.  So in large part the Supreme Court got it right.

But they got the science wrong, as any geneticist reading today's decision will realize immediately. In the very first paragraph, they make no less than three errors of fact.  First, they write:
"The nucleotides that code for amino acids are 'exons,' and those that do not are 'introns.' "
Not correct.  Here's the facts: when making DNA into a protein, the cell copies DNA into RNA.  Big chunks of the RNA are spliced out and discarded.  Those are "introns."  What remains is "exons."  That's it.  The nucleotides that code for amino acids are contained within the exons, but they are not the same thing. It's not unusual for 25% or even 50% of the nucleotides in the exons to be ignored when stringing together amino acids to make a protein.

Error number 2 comes next, when the Court writes:
"They [scientists] can also synthetically create exons-only strands of nucleotides known as composite DNA (cDNA)."
Wrong again.  cDNA stands for complementary DNA, because the DNA produced is the complement of the original strand. This means that each nucleotide is replaced with its complement: A and T are complementary, and C and G are complementary.  The court gets this right later on in the ruling.

Just after this, they write:
"cDNA contains only the exons that occur in DNA, omitting the intervening introns."
Ouch! Wrong again.  cDNA simply means a complementary copy of DNA, which doesn't have anything to do with exons.  If you make a cDNA from a mature messenger RNA transcript, then yes, it will contain only the exons.  But you can make cDNA from other parts of the genome, and from other types of RNA transcripts.

There are more errors further down in the decision. For example, they write that "Nucleotides that do not code for amino acids, in contrast, are known as 'introns.' "  This just compounds one of the errors above.  They also used the term "pre-RNA" instead of the correct term "pre-mRNA."  I could go on.

It's troubling that the highest court in the land can't get even the basic facts of molecular biology right when writing a decision that has such fundamental importance to genetic testing, the biotechnology industry, and health care.  I cannot pretend to know who they got to do their biology background research, but any genetics graduate student could have done far better.

PNAS and the eHarmony dating site: a perfect match

Well, here's a shocker.  eHarmony, the online dating service, commissioned a survey that found out that couples who get married after meeting online are more satisfied than other couples.

I'm sure there's no bias in that survey.

But here's another shocker: a leading scientific journal just published the eHarmony survey as a bona fide scientific study.  The lead author is a consultant to eHarmony (and a former advisory board member) and another author is eHarmony's former research director, Gian Gonzaga.  According to the published paper, Gonzaga designed the study.

The journal in question is the Proceedings of the National Academy of Sciences (PNAS), a high-profile journal that is published by the prestigious U.S. National Academies.

Why would PNAS publish an article that is basically an advertisement for eHarmony.com?  I'm sure the editors at PNAS would argue that it's a well-executed scientific study, but they sure got lots of publicity, with articles in the Los Angeles Times, USA Today, and Nature, not to mention a short piece in Forbes. (And yes, I'm doing it too.) A cynic might point out that both eHarmony and PNAS got what they wanted.

But what about the study itself?  Well, let's take a look.  The study, titled "Marital satisfaction and break-ups differ across on-line and off-line meeting venues," is based on a survey of 19,131 people who got married between 2005 and 2012.  6,654 of these people met online, 35% of the total, which is a surprisingly high percentage.

The headline result is the claim that couples who met online have "higher marital satisfaction." People who met this way reported a satisfaction of 5.64, on average, versus 5.48 for those who met offline.  That's a very small absolute difference, but with such large numbers in the survey, even this small difference is, in a narrow technical sense, statistically significant. The satisfaction scale ranged from 1 "Extremely Unhappy" to 7 "Perfect."  So all this fuss and publicity is over a difference between 5.5 and 5.6 in a survey.

But the higher average satisfaction might have nothing to do with how the couples met.  In my reading of the study, it seems much more likely that other factors explain the difference.

Several things are immediately obvious when one looks at the composition of the online versus offline couples.  The online couples are significantly older, wealthier, and more educated: for example, 40.5% of those who met their spouse online reported an income of $100,000 or more, compared to just 26.1% of the offline couples.  These factors alone could explain the difference in marital happiness.

The authors claim that they controlled for all of these confounding factors, and that the marital satisfication score was still significantly higher for online couples. Alas, they don't provide enough details, even in their supplementary data, to evaluate this claim. I guess we're just supposed to trust them. (Note: I believe them when they say they controlled for these variables.  I'm just not sure precisely how they did it, or if the control function really eliminated all bias.) They did recruit two independent statisticians as co-authors, which is supposed to assure us that they were unbiased. But these steps wouldn't eliminate bias that might have crept in earlier, when the eHarmony-sponsored survey was being conducted.

The article also reports the marital satisfication score of specific online dating sites. Guess which one scores the highest? That's right: eHarmony.  Why am I not surprised?

At the end of the article, the authors speculate about why couples who met online might have more satisfaction in their marriages.  (This assumes, of course, that the effect is real.)  They suggest that
"among on-line dating sites, it is also possible that the various matching algorithms may play a role in marital outcomes."  
There it is!  That's the conclusion that eHarmony wanted.  I think they got their money's worth.

In many ways, this study seems like the often-criticized studies funded by drug manufacturers that find small but significant benefit for the sponsors' drugs. Certainly there's a difference here, in that the only result is that someone might be convinced to try an on-line dating site, which might not be harmful at all.

It seems that eHarmony has found another perfect match: PNAS and eHarmony.com.

(Note: The authors did make all their raw data available, a feature that is still quite rare in scientific publishing.  They deserve kudos for doing so.  I've long advocated for more openness in data release and these authors have done the community a service by releasing theirs.)

Virginia nominates extreme anti-science candidate for governor

Last week, the Virginia Republican party nominated Ken Cuccinelli for governor, in an election to be held later this year.  Just three years ago, in his current job as Attorney General of Virginia, Cuccinelli launched one of the most outrageous attacks on an academic scientist that I've seen in many decades.  His actions would not be out of place in a totalitarian state such as the Soviet Union, or perhaps in the 1950's McCarthyism era, when many Americans were blacklisted, denied jobs, and even fired because of their political views.  But in a country where the freedom to speak is a fundamental right, Cuccinelli's actions are frightening.

Cuccinelli used the power of government to intimidate a scientist with whom he disagreed.  Not just one scientist, but 40 scientists and their colleagues, all working at the University of Virginia.  His message was clear: if you disagree with me, I will come after you.  Now Cuccinelli is running for governor, and in a state fairly evenly split between Republicans and Democrats, he has a good chance of winning.

Ken Cuccinelli is a climate change denialist, one of many U.S. politicians who think that the Earth is not warming, or if it is, that the warming is unrelated to human activities.  The science is completely against Cuccinelli on this, but if he were simply scientifically ignorant I wouldn't be writing about him.  After all, he's not the only politician who ignores science when he finds it inconvenient.

Cucinelli goes further - much, much further.  In 2010, he used the power of his office as Attorney general to launch a major legal attack on climate scientist Michael Mann, who was a professor at the University of Virginia from 199-2005.  Never mind that Mann had left UVA five years earlier; Cuccinelli wanted to make a public statement, and he chose his victim carefully.  (Mann is now at Penn State, where he holds the title Distinguished Professor of Meterology.)  

Michael Mann is the author of a famous paper that reconstructed temperatures in the Northern Hemisphere over the past 1,000 years. Man showed that we are experiencing an unprecented warming trend over the last century, shown in this figure from the IPCC report

Plot of temperature over the past 1,000
years, showing a dramatic rise in the past
century.  From the Intergovernmental
Panel on Climate Change report, 2007.
Did Cuccinelli try to find scientific evidence refuting Mann's data?  No.   He simply accused Mann, with no concrete evidence, of fraudulently manipulating data.  He then served formal legal orders on UVA, demanding all emails and other corresponding to or from Michael Mann and 39 other climate scientists, plus their research assistants and administrative staff, from 1999 through 2010.  They also demanded all "computer algorithms, programs, source code or the like" created by Mann and others. Cuccinelli's paper-thin legal justification for this attack was that Mann had violated a Virginia law called the Fraud Against Taxpayers Act, and that because Mann had request grant funding from the state, Cuccinelli could go after him and everyone associated with him.

UVA showed some backbone and refused to cave.  Hundreds of professors across the U.S. signed a petition organized by the Union of Concerned Scientists. The editors at Nature published an editorial saying that "The University of Virginia should fight a witch-hunt by the state's attorney general."

Two years later, after many court hearings and countless wasted taxpayer dollars, Virginia's Supreme Court threw out Cucinelli's charges and the case was over.


But just last week, Virginia Republicans nominated this modern-day McCarthyite to be their candidate for governor.  You can be sure that if he wins, Cuccinelli will use the heavy hand of government to intimidate anyone who disagrees with him.  His past actions show that he doesn't care about free speech or free inquiry, and he seems eager to go after anyone who might discover facts that he doesn't like.  I'd hate to be a professor at any of Virginia's universities if Cuccinelli takes over the reigns of power.

Poison for pain, the homeopathic way


At my local mega-grocery store last weekend, I happened to stroll down the aisle dedicated to homeopathic treatments.  I saw shelf after shelf of brightly colored packages, all claiming health benefits.  Most of these "medicines" were not cheap.

Amazing.  To an average shopper, all of these products look like real medicine.  The packaging is similar, the claims are similar, and it's all on display at a respectable grocery store.  The difference, though, is that none of these products do what they claim to do.  Thanks to a special exception for homeopathy created all the way back in 1938, none of the claims on these medicines need to be tested.  The homeopathy aisle is an organized, state-sanctioned scam.

The 1938 law was the brain child of a U.S. senator, Royal Copeland, who happened to be a homeopath.  Sen. Copeland inserted language into a major food and drug law that declared homeopathic preparations to be drugs.  It also allowed homeopaths themselves to maintain the official list of these drugs, called the Homeopathic Pharmacopeia.  Talk about the fox guarding the henhouse!  Thanks to aggressive lobbying by homeopaths, homeopathic ingredients are not subject to the normal review required of real drugs.  Most importantly, homeopathic drug makers do not have to prove their products are effective.

Homeopathy is based on the long-discredited beliefs of Samuel Hahnemann 200 years ago.  Hahnemann thought that "like cures like," as long as you dilute the substance sufficiently.  Thus caffeine will cure sleeplessness, poison ivy extract will cure an itch, and paralyzing plant toxins will cure pain.  None of this is true.

The other key principle of homeopathy is that the more you dilute something, the stronger its effect.  This is not only wrong, but it is exactly the opposite of what really happens.  Greater dosage levels, unsurprisingly, have stronger effects.  In Hahnemann's defense, science wasn't very far along when he came up with these notions.

Real medicine moved on long ago.  But homeopathy persists, because there is money to be made - lots of money.

Back to my grocery store.  Several shelves were filled with something called Topricin(R), which claims to relieve pain. Sounds like a medicine, right? Real drugs often use "cin" or "in" in their names because the word "medicine" itself ends with that sound.  Clever!  In front of me I saw Topricin for pain, Topricin foot cream, even Topricin for children. The Topricin packages and the company's website proclaim, in big letters, "Ideal Pain Relief", and in slightly less big letters: "Safe.  Effective. Free of Side Effects."  It also claims:
"Topricin's 11 homeopathic medicines are proven to be safe and effective for the elderly, pregnant, children, pregnant women and all skin types.  Experience Topricin's relief for damaged muscle, tendon, ligament, and nerve tissue."
This is simply not true.  It even seems to go beyond the bounds of what the (very weak) FDA regulations allow.  The website specifically claims that Topricin is effective for arthritis, back pain, bruises, bursitis, fibromyalgia, minor burns, tendinitis, and more.

Well, what is it?  Let's look at just two of the homeopathic ingredients in Topricin:

  • Belladonna 6X................. Treats muscles spasms, night leg cramps
  • Heloderma 8X................. Relief of burning pain in the hands and feet

Belladonna for pain?  Belladonna is one of the most toxic plants known to man.  Eating just a few small berries is lethal.  And the one study I could find showed that it has no clinical effect when used in a homeopathic preparation.  That's lucky for unwitting consumers: if it wasn't so diluted, Belladonna would make them very sick indeed.

Heloderma?  That's the venom from a gila monster.  Although rarely fatal, it causes severe pain, bleeding, nausea, and vomiting.  This is not something I would take for pain - and I certainly would never give it to children.

I know that Big Pharma is often guilty of deceptive marketing, and I've criticized Pharma many times.  But CAM ("complementary and alternative") pharma is every bit as bad.  Big CAM takes advantage of generous laws to make medical claims with impunity, often skirting as close as possible to what the law permits.  And the Big CAM companies profit handsomely in the process.  Everything on the Topricin package - the name, the packaging, the claims - is designed to make the consumer think that it is an effective pain treatment.  It's not.  It's a modern package of snake oil.

The Physics of Golf

[Herman Erlichson was a physicist and a historian of science (he had Ph.D.s in both). He was also an avid golfer, and he was my uncle.  He passed away just over a year ago, and I've been wanting to write this column ever since.  We corresponded frequently when I was a teenager, in a time when hand-written letters were still common.  Here is a small anecdote.]

Everyone who plays golf knows that the driver hits the ball the farthest of any club.  It also has the lowest launch angle, or "loft."  Clubs with high loft, such as a sand wedge, pop the ball very high up in the air, but don't hit it very far.

The universe of people who both play golf and also know college-level physics may not be very large, but everyone in this club has puzzled over this conundrum: why is it that a driver has a loft of only about 10 to 12 degrees?  That seems far too low.

Exactly 30 years ago this month, my uncle Herman Erlichson figured this out.  It's the spin.

He published the answer in a serious physics journal [1], but I'm guessing that most golfers don't read physics journals.  So here is what he found.

Everyone in freshman physics learns that the optimal launch angle for a projectile - the angle that makes a ball fly the farthest - is 45 degrees, in a vacuum.  But in the game of golf, 45 degrees is the angle of a pitching wedge, which (as every golfer knows) hits the ball only a short distance, about half as far as a driver.

Now the physics calculation assumes that the ball is in a vacuum, but still: how come the presence of air makes the optimum angle so much lower?  Or as my uncle put it, in his classic understated style:
"The large discrepancy between the approximately 11 deg of loft for the golf driver club and the 45 deg maximum range angle for a vacuum was the motivation to begin a study of the question of maximum projectile range in the presence of air resistance, with particular application to the flight of a golf ball." [1]
The analysis itself is technically very complex, involving 3 forces: gravity, drag (resistance caused by air friction), and lift, caused by the backspin on the ball.  All three are big factors, but the theoretical result of 45 degrees only accounts for gravity.  

Air friction (or drag) turns out to have a quadratic effect, as my uncle showed.  In other words, the drag increases in proportion to the square of the velocity of the ball.  So hitting it harder causes a very rapid increase in drag.  Here's his graph showing how the angle is affected by quadratic drag:
One consequence of "quadratic drag" is that hitting the ball a lot harder only yields a modest increase in distance.  More important, though, is that if we just consider gravity plus drag, the best angle to launch a golf ball is 35 degrees.  Lower than 45, but still nowhere near the angle of a modern driver.  And the distance here is still too low, only 336 feet (112 yards).

My uncle Hymie figured out that backspin makes a huge difference. Backspin generates lift, keeping the ball in the air much, much longer.  My uncle derived equations that allowed him to calculate how the lift force increases with the rate of spin and the speed of the ball.  This produced a very different picture of how far the ball would carry at different angles, shown here:
After accounting for lift, the optimum angle is 16 degrees, and the ball flies about 200 yards.  (This assumes a typical launch speed by the standards of 1983. The much longer drivers used today create a much greater speed off the tee.)  The remaining different between the actual loft of 10-12 degrees can be explained by the fact that for a drive, the teed-up ball is struck just past the bottom of the swing. This makes the launch angle slightly higher than the loft of the club.

There you have it: when you account for all the forces at play, the optimum angle for a golf driver really is around 10-12 degrees.

My uncle Herman Erlichson loved the game of golf and played often, despite having a seriously weakened leg, the after-effect of a polio infection that he contracted in the 1950's.  He might have struggled to master the game itself, but when it came to the physics of golf, he solved a mystery that had puzzled physicist-golfers for decades.

Reference
H Erlichson. American Journal of Physics 51:4 (1983), pp. 357-362.

For all 95 of Herman Erlichson's scholarly papers, including his paper on the physics of golf, see his Google Scholar page.

Myriad Genetics CEO Claims He Owns Your DNA


With the Supreme Court about to hear a landmark case on gene patents, Myriad Genetics, the company that owns the patents under scrutiny, is going on the offensive.  I've written about this case before, when the patents were first thrown out by one court, and then restored by another.  Now the Supremes will have the final say.

Just last week, geneticists Jeffrey Rosenfeld and Chris Mason wrote a commentary for the Washington Post that warned about the consequences of companies owning the rights to our gene sequences.

Today, in a letter filled with non sequiturs and distortions, Myriad Genetics' CEO Peter Meldrum, worried about whether his company will be able to maintain their monopoly on a test for which they charge $4000, responded.  Let's look at his claims.

First, though, let me remind readers that the genes in question, BRCA1 and BRCA2, are linked to an increased risk of breast and ovarian cancer, a risk that was first discovered in 1994 by scientists at the University of Utah.  Myriad Genetics owns a patent on these genes, and as I wrote last year:
"Thanks to these patents, you can’t look these genes in your own body without paying a fee to Myriad. Sounds ridiculous, right? Well, that was the state of gene patents until last May [2011], when judge Robert Sweet ruled that the Myriad’s patents were invalid."
Myriad appealed the decision, and the appeals court overturned Judge Sweet, buying into the argument by Myriad's lawyers that "isolated DNA" is not the same as the natural DNA, and that this distinction allows companies to patent it.  This is scientific nonsense for many reasons: for one thing, the process of isolating DNA does not create an artificial molecule. The body's own cells isolate DNA all the time, in the process of turning it into proteins.  But the appeals court accepted the argument, perhaps just because they wanted to uphold the patents.  So now the Supreme Court will re-examine this scientifically ridiculous claim.

Now let's look at CEO Meldrum's letter.  He first claims that Myriad's patents
"were essential to developing diagnostic tools that have been used by more than 1 million women to understand their hereditary risks of breast cancer and ovarian cancer."
This claim is simply false.  Myriad's patents made no contribution at all (and certainly weren't "essential") to the diagnostic tools used to detect mutations.  I know something about these tools, which I've been using in my own research for over 15 years.  Furthermore, academic medical centers were offering their own diagnostic tests on the BRCA genes, at a lower cost than Myriad, until Myriad's lawyers forced them to stop.  So Myriad's patents have increased costs to patients and, if anything, slowed down progress on making the tests faster and cheaper.

Second, Meldrum writes:
"Were these molecules derived in part from natural material? Sure. But that is true of many patents. Labs routinely turn naturally found molecules into innovative medicines and get patent protection."
One's jaw drops at this irrelevant non sequitur.  Myriad has never created "innovative medicine" or any other sort of medicine.  And the BRCA gene tests are not medicine: they are a diagnostic test that reads your DNA and tells you if you have harmful mutations in two specific genes.  Myriad's patents have nothing to do with medicines that treat breast and ovarian cancer - although it's clear that Meldrum would like us to think otherwise.

Third, Meldrum claims:
"Our tests are also accessible; some 95 percent of patients get insurance coverage, and we offer the test for free to those who cannot afford it."
This too is irrelevant, and also untrue.  The fact that 95% of patients have insurance, even if true, has nothing to do with whether or not genes should be patented.  And this merely hides the fact that Myriad's test is outrageously overpriced, at $4000 per patient.  The actual costs of testing for this gene should be far lower: we can now sequence an entire genome for $4000, and this test only looks at 2 genes out of more than 20,000.

Meldrum also throws out the unproven claim that Myriad offers it for free to those who cannot afford it.  Really?  Who decides if someone can afford it? If a woman can scrape together the $4000 with great hardship, does Myriad give her a break on the price?  I doubt it.  And what does this have to do with Myriad's supposed right to own your genes?

Fourth, Meldrum makes the remarkable claim that
"Our patents have also promoted additional research; 18,000 scientists have studied the genes, resulting in 10,000 published papers."  
This is just unfounded bragging.  Even the most wildly successful scientists would be very careful about claiming that that 10,000 papers have been based on their work.  In the case of Myriad, this is just false.  If you do a PubMed search for BRCA1, you can indeed find over 9,600 papers, as I did today.  However, there is no evidence whatsoever that these papers were even remotely supported by Myriad's patents.  It is far more likely that the patents prevented additional research on the BRCA genes.  The vast majority of research on these genes was supported by the public, which in the U.S. means by the National Institutes of Health.  Meldrum's boastful claim is absurd.

It's worth noting that the original paper describing the link between BRCA1 and breast cancer was published by a multi-institutional team from the University of Utah and other places, who were supported by multiple grants from the NIH and from the Canadian government.  Myriad Genetics subsequently licensed the patent rights from Utah, and has used them ever since to maintain its monopoly and prevent others from developing tests on the BRCA genes.  To claim that its patents promote innovation is pure nonsense.

The bottom line is that no one invented your genes, and no private company should be able to tell you that you can't even read your own DNA.  Today, you can get your DNA sequenced for less than the cost of the Myriad test.  Using free software (developed by my lab), you can scan that DNA for mutations in BRCA1 and BRCA2. And no company should be able to tell you not to.

Peter Meldrum's letter reveals that he doesn't care very much about the truth.  Meldrum made $4.87 million in 2011 as CEO of Myriad, so it's pretty clear what motivates him. Myriad's use of its patents to charge exhorbitant prices to women at risk for breast and ovarian cancer does not demonstrate innovation. It just demonstrates greed.


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.