Direct from the Researcher

Another week, another amazing LEND opportunity!

The center that hosts "my" LEND program has an ongoing brown-bag research-seminar series where distinguished researchers come in for one-hour presentations on their ongoing work. One of the LEND assignments involves attending one of these presentations each semester and reporting back. My interdisciplinary team (with an autism focus) chose to attend last Friday's presentation: “Gene x Environment Interactions Contributing to Autism: Lessons Learned from the UC-Davis Center for Children’s Environmental Health and Disease Prevention,” presented by Dr. Isaac Pessah.

Little did I know when we signed up at the beginning of the semester to attend this talk, that Dr. Pessah would be discussing an article that would go online as a pre-pub just a week and a half before, and already be getting the blogospheric once-over right before we got to hear him in person!

The article in question is Blood Mercury Concentrations in CHARGE Study Children with and without Autism. The authors are Irva Hertz-Picciotto, Peter G. Green, Lora Delwiche, Robin Hansen, Cheryl Walker, and Isaac N. Pessah; and the sponsoring institution is the MIND Institute of UC-Davis.

Quick detour about the MIND Institute -- this is an organization whose co-founders were parents of children with autism, searching for a cure and ready to lay the blame with vaccines. (See All Things Considered transcript from Jan. 20, 2003). Since its inception, the MIND Institute has focused on environmental considerations in autism. They operate from the position that the rise in autism prevalence can not be entirely accounted for by changing definitions, diagnostic substitution, and increased awareness/education.

Given that background, it's not at all surprising to see a study comparing mercury concentrations in the blood of children with and without autism.

The conclusions might not be expected, though.

Conclusions: After accounting for dietary and other differences in Hg exposures, total Hg in blood was neither elevated nor reduced in CHARGE Study preschoolers with AU/ASD as compared with unaffected controls, and resembled those of nationally representative samples.

They used a substantial sample of preschoolers on the autism spectrum, plus two control groups: one group with non-autism developmental disabilities, and one typically-developing group. They interviewed mothers to determine household and medical and dietary exposures to mercury.

It turned out that the biggest contributor to blood mercury levels in all groups was fish consumption. Once you account for fish consumption, there were no significant differences in blood mercury levels between groups. In fact, before controlling for fish consumption, the blood mercury levels for the autism group were actually lower than the other groups. Because the ASD kiddos ate less fish!!

Sullivan over at LeftBrain/RightBrain does a fine parsing of the study and the various online reactions to it. I won't try to re-do a job that's been already well-done!

For me, it's rather a thrill to be hearing first-hand, right from the mouth of one of the actual study authors, that the ASD kiddos had similar blood-mercury levels, and any differences were pretty much all about the fish. Now, this doesn't say anything directly about mercury and autism causation. The authors are very straightforward about that. Still it's another useful counterweight to what has become an insidious public perception. It's not the thimerosal, folks!!

P.S. You may have noticed that the title of Dr. Pessah's talk was about genes & environment. He also addressed a second paper, not yet publicly available, that delved deeper into genetic complexity than my poor notes were able to keep straight in the absence of being able to refer to the actual PowerPoint slides! When the paper actually comes out, I might take a whack at it. Or it still might turn out to be pretty much beyond my ken.

Of Flu Shots and Superstitions

Well I ain't superstitious,
But a black cat crossed my trail...

-- bluesman extraordinaire Willie Dixon

Generally I prefer to think that superstition and medicine shouldn't have anything to do with one another.

As I've said before, I'm an evidence-based kind of gal, and I like to have a medical team with the same basic outlook.

On the other hand, when I updated Joy's excellent neurologist on her lovely on-going seizure-free string (going on 2 months this coming Tuesday!), he glanced around and said "Quick, touch wood!" We laughed together as he jokingly allowed as how pediatric neurology had more to do with superstition than one would guess...

OK everybody, touch wood for us! Quick! Doctor's orders!

I also found myself doing something perhaps related to touching wood at Joy's recent primary care appointment. I got her a flu shot. And I requested a thimerosal-free dose.

Now, intellectually I am thoroughly convinced by the studies that, time after time, fail to find any connection or correlation between thimerosal and autism. In addition, if there were any connection, by now we should be seeing decreases in ASD diagnoses since thimerosal began to be taken out of vaccines as far back as 1999 -- and that drop has not happened.

So why did I ask for the thimerosal-free formulation for Joy?

Touch wood! I don't have any better reason than that. And I'm a little bit peeved at myself, and a lot frustrated at the anti-vaccine movement that has managed to instill this gut-level unreasoned uneasiness, even in me. An evidence-based kinda gal, or so I like to think. Emotions are such pesky beasts, aren't they?

The flu shot, recommended but not required, is about the last holdout for the regular use of thimerosal as preservative in childhood vaccines. The latest CDC guideline this year has expanded the recommended population for flu shots. They now recommend that everyone from 6 months to their 19th birthday, and also everyone over 50, get the shot. I think it used to be only up to age 5 for kids. Poor Rose, age 6 this year, got her shot this morning (didn't feel the need to specify formulation for her). Fortunately we didn't have long to wait in the doctor's office for her to stress about it. She cried almost as little as Joy this year, which is to say just a few whimpers -- Rose's whimpers were before the shot, Joy's were after.

JoyDad and I didn't whimper at all when we got ours at our respective workplaces. Or so he tells me, anyway.

Funny postscript to this year's flu shot adventure. Rose came in and told JoyDad that she'd had her flu shot.

JoyDad asked, "Where did you get it?" thinking left arm, right arm, leg, derriere, where?

Rose replied, "At the doctor's office!!"

A Queasy Comparison

As the mother of a child with autism, I’m occasionally asked what I think about “the vaccine thing,” i.e. the purported link between vaccines and autism.

To answer that question, let me tell you a story. It will seem unrelated at first, but stick with me.

From 1956 to 1983, pregnant women in the U.S. suffering from “morning sickness” had access to an effective medication called Bendectin. Unfortunately during part of that time another medication, thalidomide, was also on the market in a number of countries, as a sedative that also had some nice anti-morning-sickness effects (it was never approved in the U.S., but was distributed to some extent here on an experimental basis). The manufacturers claimed thalidomide was safe for use in pregnancy, though testing had been minimal or non-existent. After the 1957 introduction of the thalidomide, unusual birth defects began to appear in striking numbers. Thalidomide was removed from the market in 1962 and its manufacturers expended great effort in claiming innocence and trying not to be held liable for its awful effects, effects which turned out to be easy to replicate and impossible to deny.

Meanwhile, Bendectin continued to rise in popularity, eventually being used by as many as 1 in 10 pregnant women in the U.S. In the wake of the thalidomide disaster, Bendectin came under serious scientific scrutiny – so much so that perhaps no other medication has ever been so thoroughly studied for use in pregnancy. The results held firm in study after study: no adverse associations with Bendectin were ever established.

However, as one might expect in that large a population, a certain number of women taking Bendectin also gave birth to children with birth defects. After what happened with thalidomide, blaming Bendectin – despite all the studies to the contrary – was not that big a mental leap. Soon the lawsuits started to pile up. Eventually the manufacturer Merrell Dow pulled the drug off the market due to the financial pressure, but continued to mount an exceptionally successful defense to the various suits that came to trial, among them a class action suit brought by over 800 plaintiffs and an individual case that went all the way up to the Supreme Court and had an impact on evidentiary standards in the process.

No plaintiff ever received damages after a Bendectin-related trial. (Current Controversies in the Biological Sciences, p. 170)

So, there's been no Bendectin on the market for suffering pregnant women in the U.S. for the past 26 years, with no discernable decline in birth defects. Hospitalizations due to hyperemesis (extreme vomiting) of pregnancy, though, increased considerably. Click here & scroll down to see a chart of the trends. Fortunately for our neighbors to the north, a generic version of Bendectin called Diclectin has been available in Canada all along. And, as my OB advised me during my pregnancies, you can buy Bendectin’s ingredients separately, doxylamine succinate as Unisom and pyridoxine as Vitamin B6, and take ‘em yourself -- only on the advice of your own physician, please!

Now, back to the vaccines.

Vaccines do occasionally have adverse effects, sometimes dire ones. To take that fact into account, the U.S. government has set up the National Vaccine Injury Compensation Program (VICP), an alternative to the court system that provides for vaccine-injury compensation in cases where a credible scientific rationale can be advanced, without laying all the lawsuits on the backs of the vaccine manufacturers.

Thank God for the vaccine court. Because if there were no such process in place, autism-related lawsuits might well drive the vaccines right off the market in the U.S., just like Bendectin, despite all the science that finds no evident connection between vaccines & autism. And there’s no do-it-yourself over-the-counter alternative for protection against pertussis, diphtheria, measles, polio... all those diseases that used to kill and maim so many people before vaccines came on the scene.

People get into big online slugfests about vaccines and autism all the time. I'm not really spoilin' for a fight myself, because nobody wins those things. I could wish that coming out online in support of mainstream science and the American Academy of Pediatrics weren't potentially a lightning-rod kind of thing to do! What a world, what a world.

Anyway. That's where I'm coming from on the "vaccine thing." Just in case my readers would like to know.