Yet another risk assessment finds BPA safe

While the media continues to report activist fears over chemicals in plastics, another risk assessment buttresses the overwhelming consensus in science that the chemical is safe.

“An expert panel led by scientists at Gradient Corporation in Cambridge, Massachusetts completed an extensive scientific review of the reproductive and developmental effects of bisphenol A. Based on its review of all the relevant scientific literature, the panel found no consistent evidence of reproductive or developmental effects of bisphenol A at typical human exposure levels. The review considered all studies published through July 2008 that examined reproductive and developmental toxicity in animals at low bisphenol A doses. No studies were excluded based on study design or source of funding.

According to Dr. Lorenz Rhomberg, the senior author of the review, “The hypothesis that the low levels of bisphenol A to which people are exposed could disrupt reproduction and development is not supported by coherent, consistent, or compelling evidence.”

This is the second review conducted by the Gradient corporation and the third major assessment funded by industry (the other was overseen by Harvard’s Center for Risk Analysis).

Some scientists, notably the George Washington university epidemiologist David Michaels have expressed doubt about industry-sponsored studies of BPA, noting that independently funded studies have found a risk where industry funded studies haven’t.

But the findings of these three industry-sponsored reviews all concur with the findings of independent risk assessments conducted by the European Union’s Food Safety Authority, the Japanese government, NSF International, and the Center for the Evaluation for Risks to Human Reproduction in the U.S. (Moreover, in his article for the Washington Post, Michaels radically undercounted the number of studies on BPA and ignored the problem of whether good laboratory practices were followed in the independent ones; an independent study with a sample size of six rodents is not going to have the statistical reliability of an industry-funded study containing hundreds of rodents).

Given that so many scientists have concluded that there are no reproductive or endocrine risks from BPA, the media need to start questioning whether the risks claimed for BPA by a handful of scientists and a heaped serving of environmental activists are actually based on firm science.

Acrylamide finding challenges rodent carcinogen tests, media

Acrylamide was first discovered in 2002 as a compound created in food at high temperatures during frying, roasting and baking, and led, initially, to a health scare over french fries and potato chips, when high doses were associated with cancer in lab rats. Research in 2003 then showed that there were higher quantities of acrylamide than previously thought in breakfast cereals, coffee, and toast.

As STATS reported at the time, the media quickly began cooking up a health scare and downplaying research which failed to connect the compound to cancer in humans (and, in fact, found a lower rate of certain cancers among those with the highest intake of dietary acrylamide).

Now, results from the Netherlands Cohort Study on diet and cancer have failed to show an association between acrylamide and “colorectal, gastric, pancreatic, and esophageal cancer risk.” The abstract also notes that “some subgroups deserve further attention,” based on particular factors. Of course, you might want to stay away from foods high in acrylamide for the simple reason that they may be high in carbohydrates and fat.

Still, the growing absence of evidence that acrylamide causes cancer in humans reminds us of the need to be cautious in interpreting the results of studies where rodents are fed massive doses of chemicals.

Research headline of the day: Two-fisted eaters…

Medpage Today reports on some less-than-surprising research into obesity published in the British Medical Journal Online: “Two-Fisted Eaters Who Wolf Down Food to Bursting Point May Be Overweight.” The article notes that:

“Past studies have found that eating quickly is associated with being overweight, but this research adds that combining it with eating until full could have a substantial impact on being overweight.”

If the cautious deployment of “may” and “could” seems odd and a little disappointing, it is because the study was cross sectional and thus cannot determine causality. The researchers called for prospective cohort studies to confirm the findings. Still, two-fisted eaters who wolf down food to bursting point may want to reconsider the whole “bursting point” part of their nutritional game plan.

Pharma should adopt web 2.0 to track adverse effects

Peter Pitts urges pharmaceutical companies to embrace web 2.0 and social networking technologies to improve drug safety and education… more

When eliminating one risk increases another

Richard Donkin’s review of “Everyday Survival: Why Smart People Do Stupid Things” in the Financial Times reminds us of what can go wrong when we try to address relatively rare, but nonetheless serious, risks and fail to think through the consequences:

When carmakers began to fit airbags as a safety device in the early 1990s a number of fatalities among infants in front seats led to a recommendation that babies be strapped in the rear. Sadly, out of sight meant out of mind in some tragic cases, when infants were forgotten by their parents who left them in hot cars on sunny days. Between 1990 and 1992 when car airbags were rare, only 11 such deaths were recorded in the US. But between 2003 and 2005, when almost all new cars had airbags, some 119 children died from being left in cars.

When statisticians forget how to do statistics

A great example of how statistical analysis is not always immediately intuitive comes from testing statisticians. As Nassim Taleb notes in “The Black Swan:”

“In 1971, the psychologists Danny Kahneman and Amos Tversky plied professors of statistics with statistical questions not phrased as statistical questions. One was similar to the following (changing the example for clarity): Assume that you live in a town with two hospitals – one large, the other small. On a given day 60 percent of those born in one of the two hospitals are boys. Which hospital is it likely to be? Many statisticians made the equivalent of the mistake (during a casual conversation) of choosing a larger hospital, when in fact the very basis of statistics is that large samples are more stable and should fluctuate less from the long-term average – here, 50 percent for each of the sexes – than smaller samples. These statisticians would have flunked their own exams.”

Bottled water study junk, says leading microbiologist

A new study on the chemical risks of bottled water by the Environmental Working Group (EWG), an activist group with a long history of grabbing media attention with badly-done studies, has come under fire from one of the world’s leading experts on water safety.

Dr. Stephen Edberg, professor in the Department of Laboratory Medicine and Internal Medicine at the Yale University School of Medicine, developed the most commonly used test to ascertain drinking water safety. He criticized the EWG for making scientific claims based on evidence that bodies such as the World Health Organization have rejected. In particular, he criticized the EWG’s allegation that bottled water was more likely to promote breast cancer cell proliferation.

“The study’s ‘breast cancer’ allegation is an egregious example of specious science. The test uses cells in the test tube, indicating that breast cancer cells grew less in tap than bottled water. The reason is obvious, tap water contains chlorine, which inhibits cell growth. No valid research would use tap water to examine cells in culture.”

A quick, but non-exhaustive, survey of media coverage of the EWG study (New York Times, AP, Bloomberg WebMD etc) found that reporters didn’t examine the scientific validity of the group’s findings or question the methodology of the study by seeking comment from independent scientific experts. Most of the articles repeat the EWG findings with the only added comment from bottled water industry representatives.

While we don’t approve of this kind of enhanced press release journalism – call us overly cautious, but we think it’s wrong to scare the public without checking out whether the scare is true – we cite Dr Edberg’s comments despite the fact that they are in a press release put out by Burston Marsteller and because he is a real scientist with track record of expertise in the subject. And it’s somewhat useful to have that kind of input into an issue like this, dontcha think?

Jonas Brothers for president? The kids speak (but some can’t quite add)

As my colleague Rebecca Goldin noted, if you are going to try and divine the outcome of a presidential election, you might as well turn to school children as regression analysis. Over 250,000 school kids cast their “vote” for president in the Scholastic Election Poll, which has only been out of step with adult voters twice since 1940.

Well, the results of this year’s poll are in, and children in grades one to 12 delivered a decisive mock victory to Obama with 57 percent of the vote to John McCain’s 39 percent.

In three swing states, McCain outperformed Obama: Colorado (61 percent versus 36 percent); Indiana (51 percent versus 47 percent); and Missouri (49 percent versus 47 percent).

There were also some notable write-in candidates garnering votes. In a sign that for some, the rift created in the Democratic presidential primaries has not healed, Hillary Clinton reaped the highest number of write-ins (11 percent of the four percent).  Others, believing that the task of the president was to teach the world to sing, opted for Miley Cyrus (despite her Vanity Fair photoshoot scandal) and the Jonas Brothers  – all three of them.

Of course, the bigger problem with choosing reliable predictors of presidential elections is that the overall sample of presidential elections that can be assessed for uniform predictors is too small to deliver a good indication of reliability.

Doctor debunks 500 news stories in crusade against junk science

Another review of Dr. Ben Goldacre’s new book “Bad Science,” this time in the Daily Telegraph, notes that since he started writing for the Guardian in 2003, he has debunked more than 500 news stories (including some which appeared in the Guardian itself aswell as the Telegraph.) As Ed Lake notes:

“…the inability of the press and public to evaluate evidence, [Goldacre] argues, has become a public health issue.

Much of the MRSA scare was a circus. MMR was a debacle. Cases of mumps were almost unheard of before the media bandwagon got started, but by 2005, there was an epidemic. The moral is clear: when the well of information is contaminated, people get ill…

Scientists failing to challenge pseudoscience

In reviewing Dr. Ben Goldacre’s new book “Bad Science,” which is based on a column Goldacre writes for the Guardian newspaper, Dr. Michael Fitzpatrick notes that

The very fact that it has been left to a junior hospital doctor to take the lead in challenging important areas of pseudoscience in modern society reflects the abdication of responsibility by the scientific establishment. This – rather than the role of the media, abject though that has been – is the real lesson of the imbroglio over the MMR vaccine, itself the subject of an excellent chapter in Bad Science.

Senior scientists must take up their responsibility to explain and defend science in public, and to set their own house in order by tackling fraud, exposing junk science and calling a halt to the abuse of university titles and academic qualifications…