Thursday, September 15, 2011

Big Fruit Is Trying to Poison You...or Not

People in positions of authority or renown ought to be careful with what they say and do. They are held to a higher standard because their actions can often have a rather influential effect on the public at large. A simple comment may be enough to sway how we think, what choices we make and may even have a huge impact on the economy. Suggesting that there may be something wrong with one product may steer people away from that product, at least for a time. It may even scare consumers away from the entire class to which the product belongs. It is very important, therefore, to do one's due diligence before saying something from a platform that reaches audiences in the hundreds of thousands. It's easy to make an error when speaking extemporaneously; we're all human, after all. But when a person's words and presentation are planned well in advance, when there is forethought, and when the topic has the potential to sway a lot of people, that person must tread carefully, dot all their "i"s and cross all their "t"s. It is disturbing when people in such public positions fail in this.

People like Dr. Oz.

Boy Meets Juice

Yesterday, September 14, 2011, Dr. Oz's show warned parents about potentially unsafe levels of arsenic in their children's apple juice.

"Some of the best known brands in America have arsenic in their apple juice." - Dr. Oz

He cited the EPA's limit of 10 ppb in drinking water and noted that the lab used by the show, EMSL Analytical, Inc., found some samples with levels higher than the EPA's limit, with one sample even being reported as high as 36 ppb, more than three times what is allowed in drinking water:

Of these [3 dozen samples from 5 brands], 10 samples came back higher than the arsenic limit allowed in drinking water.

Note: Lab results standard deviation is +/- 20%

Minute Maid Apple Juice

Lowest Sample for Arsenic: 2 parts per billion
Highest Sample for Arsenic: 3 parts per billion

Apple and Eve Apple Juice

Lowest Sample for Arsenic: 3 parts per billion
Highest Sample for Arsenic: 11 parts per billion


Lowest Sample for Arsenic: 4 parts per billion
Highest Sample for Arsenic: 16 parts per billion

Juicy Juice

Lowest Sample for Arsenic: 2 parts per billion
Highest Sample for Arsenic: 22 parts per billion


Lowest Sample for Arsenic: 3 parts per billion
Highest Sample for Arsenic: 36 parts per billion

That certainly sounds frightening. I mean, we all know that arsenic is bad. Just look what happened to the poor, lonely men in Arsenic and Old Lace. Or, for an historical perspective on the substance, see how it was used in the early 20th century in The Poisoner's Handbook. In all seriousness, arsenic is a dangerous substance in sufficient doses. It can be fatal if a large enough dose, but even at non-fatal levels it can cause cancer in various organs.

But is Dr. Oz perhaps overstating the threat? Might he be indulging in a little bit of fear-mongering to drive viewer interest and ratings?

It's a Little Complicated

Let's learn a little bit more about arsenic together. According to the FDA, which governs our nation's food safety, the story is a bit more complex than just talking about total levels of arsenic. As they state in their letters to the Dr. Oz Show, there are two general types of arsenic: organic and inorganic. Organic arsenic compounds are generally considered non-toxic in humans. It is also known that for some animals, arsenic is an essential nutrient at low levels, though similar data for humans is, as yet, unknown. In contrast, the inorganic form of arsenic is what causes all the trouble.

According to studies by the EPA, humans can be exposed to 0.009 mg/L-day with no adverse effects. This converts to about 0.0008 mg/kg-day. The lowest level that we start to see toxic effects at about 0.017 mg/L, or 0.014 mg/kg-day. That means that an average 35 lb 4-year-old (~15.9 kg) can be exposed to 0.013 mg of inorganic arsenic each day without toxic effects. Or, to put that into parts per billion, 1.3 ppb. Effects will start to be seen at cannot be detected at all until about 22.3 ppb (0.014 mg/kg-day x 15.9 kg = 0.2226 mg/kg-day) of daily inorganic mercury exposure. At much higher levels, bad things begin to happen.

Now, the problem with Dr. Oz's analysis is that it looked at total (i.e., organic and inorganic) arsenic levels in apple juice, when the type of arsenic most commonly found in apple juice is organic arsenic. He did not discuss the differences on his show, nor on his web site (as of 9/15/11). This confounding of different compounds is similar to the anti-vaccine movements confounding ethylmercury and methylmercury. He also relied on test results from only one lab, which differed greatly from the testing by the FDA and by juice manufacturers. Rather than going to a different lab for re-testing, he went back to the same lab.

And Then There's the Guilt

The ultimate result was that his show made people afraid. In a clip from the show on an ABC News report, one parent on the show even stated, as a result of Oz's rhetoric:

I'm the guy administering poison to my own children.

It was even reported that some schools were removing apple juice from their lunches in response to his apple juice episode.

In defense of his show, Dr. Oz appeared on ABC News essentially taking the "I'm just asking questions" approach. To be fair, he did say that he gives apple juice to his kids and has posted links to the FDA letters on his web site, but he did not take responsibility for instilling unwarranted fear in parents like the man who showed extreme guilt about "poisoning" his kids, nor for providing inaccurate and incomplete information.

Instead of taking a measured approach and providing all of the facts necessary to properly and responsibly inform his audience, Dr. Oz chose to run with one set of test results that are essentially meaningless when it comes to determining the safety of apple juice products. He went for spin and fear, rather than reality. Dr. Oz, you have a huge audience, and they deserve far, far better than the dreck you serve.

UPDATE: Dr. Besser has reportedly been invited to appear on Dr. Oz's show to continue discussing the topic. He has agreed and is eager to talk about it, but wants to broaden the discussion. I hope that he continues to espouse the rational, pull-no-punches approach he took with Dr. Oz in the clip linked above.

It also looks like Steve Novella has discussed this issue over at NeuroLogica, making many of the same points I did. PZ Myers has also commented on Dr. Oz over at Pharyngula.

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