Harvard hospital retracts statement about data on aspartame and cancer

This is a story about clinical research, misinterpreting said clinical research, an overaggressive Public Relations department, honest scientists, and good scientific journalism. Let’s start at the beginning.

This week, an article was published in the American Journal of Clinical Nutrition by Schernhammer et al., scientists from Brigham and Women’s Hospital, a teaching affiliate of Harvard University Medical School, that examined potential risks of certain cancers in groups that consumed diet drinks. The study identified, over 22 years, 1324 non-Hodgkin lymphomas (NHLs), 285 multiple myelomas, and 339 leukemias. They then determined their intake of diet sodas (or pop, depending on your location in the United States).

They determined that:

  • Men who had greater than 1 daily serving of diet soda had increased risks of NHLs and multiple myeloma. Women had no observed increased risks.
  • They also observed an unexpected elevated risk of NHL with a higher consumption of regular, sugar-sweetened soda in men but not in women. 
  • Neither regular nor diet soda increased risk of leukemia but were associated with increased leukemia risk when data for men and women were combined.

Based on these results, you might think that diet sodas are dangerous, at least for men. Or maybe just sodas (or pop), whether sweetened with sugar or artificial sweeteners, are dangerous. Or maybe not. The authors themselves conclude:

Although our findings preserve the possibility of a detrimental effect of a constituent of diet soda, such as aspartame, on select cancers, the inconsistent sex effects and occurrence of an apparent cancer risk in individuals who consume regular soda do not permit the ruling out of chance as an explanation.

In other words, there’s really not much there. And that’s not bad in science. They tried to look for something, and they didn’t find anything. Maybe those men who drank sodas heavily had other confounding risk factors like obesity, diet, or other environmental factors. Or it may just be random.

At this point in the story, it’s just one of those published articles that really isn’t much of anything. No one would make much of it, because it really doesn’t provide much evidence that aspartame or sodas are that dangerous. 

Then Brigham and Women’s Hospital puts out a press release with an attention grabbing headline of “The truth isn’t sweet when it comes to artificial sweeteners.” Now, if you saw that headline, you would have assumed that the article provided a solid conclusion that there was a direct causal link between artificial sweeteners and certain cancers. But the article said no such thing, it showed a very weak link, if one at all.

I guess the real scientists at Harvard saw the press release and decided their reputations mattered more than marketing the hospital in an unethical way. But whatever the real story, the hospital issued an “apology”:

It has come to our attention that the scientific leaders at Brigham and Women’s Hospital did not have an opportunity, prior to today, to review the findings of the paper entitled Consumption of Artificial Sweetener and Sugar Containing Soda and the Risk of Lymphoma and Leukemia in Men and Women”, to be published in today’s Journal of Clinical Nutrition (sic). Upon review of the findings, the consensus of our scientific leaders is that the data is weak, and that BWH Media Relations was premature in the promotion of this work. We apologize for the time you have invested in this story.

Uh,  it’s actually the American Journal of Clinical Nutrition, shocking they can’t get that right. Maybe I’m just being picky, but Public Relations should represent the organization better than that. 

Robert Bazell, NBC News reported that “the situation is a great example of why the public often finds science confusing and frustrating. After being asked some hard questions – and just before the report was to be released —  the hospital changed its tune.”

Bazell further reports that “the conclusion was so weak that the researchers had to submit it to six journals before they found a seventh, the American Journal of Clinical Nutrition, that would publish it. Few reporters read that journal. If it was not for the frightening headline no one would have known about this study.”

This study was a well-intended one that could have found a causal link if there was one, because of the way it sought out information. But it did not find the link, and that is how research is done. Sometimes, you find evidence of the null hypothesis, that artificial sweeteners don’t do anything.

And just in case there’s any confusion, Bazell reported that the lead author Schernhammer, when asked whether the published “research proves that aspartame is dangerous, she answered emphatically, ‘No, it does not.'”

The vast weight of evidence shows aspartame is safe. This doesn’t add to that weight, it just doesn’t support that it causes cancer. And it proves one more thing. Do NOT use press releases as your scientific proof source. They aren’t worth anything, because they aren’t written by scientists, and they are used to promote the facility. 

Drink your diet soda. Or pop. Your choice.

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Overhyped GMO corn study gets more scrutiny

Over the past couple of weeks, I have discussed a study by Gilles-Eric Séralini et al. published in Food and Chemical Toxicology that concluded that glyphosate-resistant NK603 GMO corn developed by Monsanto causes severe diseases such as tumors in rats. Of course, the study was picked up by many anti-science groups and broadcast widely as “GMO foods cause cancer.”

Except, the study really was badly done. Read about my deconstruction of the study here. And read how GMO’s have become the “global warming denialism” of the left. The study was ridiculed widely in science and skeptics blogs. A new article in Nature News summarized the criticism of Séralini et al.:

The biggest criticism from both reviews is that Séralini and his team used only ten rats of each sex in their treatment groups. That is a similar number of rats per group to that used in most previous toxicity tests of GM foods, including Missouri-based Monsanto’s own tests of NK603 maize. Such regulatory tests monitor rats for 90 days, and guidelines from the Organisation for Economic Co-operation and Development (OECD) state that ten rats of each sex per group over that time span is sufficient because the rats are relatively young. But Séralini’s study was over two years — almost a rat’s lifespan — and for tests of this duration, the OECD recommends at least 20 rats of each sex per group for chemical-toxicity studies, and at least 50 for carcinogenicity studies.

Moreover, the study used Sprague-Dawley rats, which both reviews note are prone to developing spontaneous tumours. Data provided to Nature by Harlan Laboratories, which supplied the rats in the study, show that only one-third of males, and less than one-half of females, live to 104 weeks. By comparison, its Han Wistar rats have greater than 70% survival at 104 weeks, and fewer tumours. OECD guidelines state that for two-year experiments, rats should have a survival rate of at least 50% at 104 weeks. If they do not, each treatment group should include even more animals — 65 or more of each sex.

“There is a high probability that the findings in relation to the tumour incidence are due to chance, given the low number of animals and the spontaneous occurrence of tumours in Sprague-Dawley rats,” concludes the EFSA report. In response to the EFSA’s assessment, the European Federation of Biotechnology — an umbrella body in Barcelona, Spain, that represents biotech researchers, institutes and companies across Europe — called for the study to be retracted, describing its publication as a “dangerous case of failure of the peer-review system”.

Because of the low quality of the research, the European Food Safety Authority (EFSA) in Parma, Italy, issued its initial assessment of Séralini’s paper, which slammed the conclusions.

The numerous issues relating to the design and methodology of the study as described in the paper mean that no conclusions can be made about the occurrence of tumours in the rats tested.

Therefore, based on the information published by the authors, EFSA does not see a need to re-examine its previous safety evaluation of maize NK603 nor to consider these findings in the ongoing assessment of glyphosate.

“The design, reporting and analysis of the study, as outlined in the paper, are inadequate,” said the EFSA in a press release, and added that the paper is “of insufficient scientific quality to be considered as valid for risk assessment”.
 
On the basis of the publication, the BfR has come to the conclusion that the authors’ main statements are not sufficiently corroborated by experimental evidence. In addition, due to deficiencies in the study design and in the presentation and interpretation of the study results, the main conclusions of the authors are not supported by the data.
Séralini refuses to release any of his data for public scrutiny, which is highly unusual for peer-reviewed research. One of the most important features of science is being open to the bright lights of criticism, which means review of data. I guess Séralini isn’t really happy that his research is being blasted by scientists worldwide, since the design, analysis, statistics, and conclusions barely met the standards of a high school science fair.
 
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The best reason to detest the anti-vaccine movement

There are many reasons to loathe the anti-vaccine lunatics. Their decisions are based on pseudoscience and uninformed opinions. They listen to uneducated individuals instead of researchers who spend their lifetimes trying to understand the nuances of vaccines, the immune system and infectious diseases. They look for nonexistent conspiracies to such a point that they sound like a schizophrenic undergoing a psychotic break. They pretend to be interested in their children, and you almost want to believe them, but their conclusions are based on so little evidence, you begin to think that it’s all about the hype rather than the children.

Continue reading “The best reason to detest the anti-vaccine movement”

Republican governor Nikki Haley is anti-vaccine and pro-cancer

The Charleston (SC) Post and Courier reports that Republican South Carolina Governor Nikki Haley vetoed a bill that would have provided sixth- and seventh-graders with information about the HPV vaccine. The vaccine would have been provided at no cost to all seventh-graders whose parents allowed them to have the vaccination. The bill had strong support from both Democrats and Republicans in the South Carolina legislature.

The HPV vaccine provides immunity to men and women against several types of human papilloma virus which is associated with with over 20,000 cancers in women and 11,000 cancers in men every year. Governor Haley defended her veto by calling the bill unnecessary and a “precursor to another taxpayer-funded healthcare mandate,” the Charleston Post and Courier reports.

State Rep. Bakari Sellers (D-Bamberg, S.C.) sponsored the bill and blasted Haley’s move, calling her decision one that… 

puts her own selfish political ambitions ahead of the people of South Carolina. This bill had bipartisan support and gives optional education and preventative vaccines to adolescents in an effort to thwart cervical cancer. This is a common sense approach to a very serious problem. To call this measure unnecessary is demeaning and insulting to the heroic women who fight this cancer everyday. I am deeply disappointed that politics once again has prevailed over women’s health.

In 2007, Haley actually co-sponsored a bill that would provide mandatory HPV vaccinations. It failed to pass through the legislature because it failed to provide opt-outs, which was corrected in the 2012 version.

Let’s be clear here. Haley did not veto this bill because of bad medicine or bad science. She vetoed it purely for political expediency and by doing so, she stands firmly against a simple inoculation that would prevent a deadly cancer. This is not a political issue, it is an anti-cancer issue. 

Vaccines save lives. I guess Nikki Haley doesn’t understand that! Maybe she’ll provide cigarettes for free to the school children of South Carolina.

Cancer prevention–supplements

Potential causes for cancer are numerous. Infections. Radon gas. Cigarette smoking. Sun exposure. Obesity. With over 200 types of cancer, each with a different pathophysiology, there may be an equal (and probably greater) number of causes. Although many causes can be easily eliminated, such as stopping smoking, testing your house for radon, getting an HPV vaccine to prevent human papillomavirus infections, and wearing sunblock to reduce the risk of melanomas, the sheer complexity and number of types of cancer means that there is probably not going to be any simple panacea to preventing (or even curing) cancer. In fact, some hereditary cancers, such as those individuals who carry genes that are implicated in breast and ovarian cancers, may not be preventable at all. Continue reading “Cancer prevention–supplements”

Infections causes 16% of cancers–what?

Ed Yong, a scientist and contributor to Discover Magazine, wrote an blog post, What does it mean to say that something causes 16% of cancers?, discussing a news report that stated that 16% of cancers around the world were caused by infections.  Here are some excerpts:

A few days ago, news reports claimed that 16 per cent of cancers around the world were caused by infections. This isn’t an especially new or controversial statement, as there’s clear evidence that some viruses, bacteria and parasites can cause cancer (think HPV, which we now have a vaccine against). It’s not inaccurate either. The paper that triggered the reports did indeed conclude that “of the 12.7 million new cancer cases that occurred in 2008, the population attributable fraction (PAF) for infectious agents was 16·1%”.

But for me, the reports aggravated an old itch. I used to work at a cancer charity. We used to get frequent requests we got for such numbers (e.g. how many cancers are caused by tobacco?). However, whenever such reports actually came out, we got a lot confused questions and comments. The problem is that many (most?) people have no idea what it actually means to say that X% of cancers are caused by something, where those numbers come from, or how they should be used. Continue reading “Infections causes 16% of cancers–what?”

Checking for pseudoscience in real science news (updated)

One of the larger problems of the internet (OK, there are a lot) is how science is discussed out in the world.  Google any science topic, and you’ll get thousand or millions of hits on any idea in science or medicine. The information is derived from other websites, news reports, rumors, or, to be cynical, from outright fabrication. In the fields of science and medicine, critical thinking is absolutely necessary to understanding it. Because it’s hard work, pseudoscience and anti-science have become quite prevalent lately.   Continue reading “Checking for pseudoscience in real science news (updated)”

Why do Americans hate Gardasil?

In next week’s issue of Forbes, Matthew Herper, the magazine’s medical editor, penned the article, The Gardasil Problem: How The U.S. Lost Faith In A Promising Vaccine, an insightful analysis of why Gardasil, the vaccine for human papillomavirus (HPV), has not become as important to vaccination strategies as measles or whooping cough.  All vaccines keep you alive, even if the disease does not appear to be scary.  There’s a belief, especially amongst the anti-vaccination crowd, that measles is just a few spots, and there are few risks to being infected.  The risk of severe complications is small, but significant.

On the other hand, the HPV vaccine does one thing and does it well–it prevents an HPV infection.  Human papillomavirus, a sexually transmitted disease, causes 70% of cervical cancers, 80% of anal cancers, 60% of vaginal cancers, and 40% of vulvar cancers.  It also prevents the majority of HPV caused oral cancers.  In other words, these diseases are in a different league of danger.  And they can be prevented. Continue reading “Why do Americans hate Gardasil?”

How pseudoscience makes its case. Part 4.

This is my continuing multi-part discussion about how pseudoscience uses logical fallacies, strawman arguments, and other rhetoric to make its case, rather than real science.  Just click on the links to read Part 1, Part 2, and Part 3.

The other day I engaged in a discussion with a well-meaning pharmacist who claimed that vitamin C could treat colds and prevent other diseases like  “cancer” (I always get annoyed  by people who lump all cancers together, when there are over 200 different cancers, all of which have different histologies, genetics, and causes).  Of course, there are a number of well-controlled clinical trials that show that vitamin C has no effect on the common cold and has no effect on cancers so far studied (see this, this, this and this).

During our discussion, she said “science should be neutral,” with the implication that I wasn’t neutral.  I happen to agree, science should be neutral and it should balanced.  But science should be based upon the scientific method not rhetoric and not using science-y words, at which the writers of Star Trek were well-versed.

So, when I say that I am (or any evidence-based real scientist), “scientifically neutral”, that means I’m willing to weigh the evidence and publications on real scientific issues.  I am not a geologist nor a paleontologist, but I was studying biochemistry when the earliest theories on what caused the Cretaceous-Tertiary extinction event 65.5 million years ago, where all the dinosaurs (well, not all, since technically modern birds are surviving dinosaurs from a cladistic point of view) and some 75% of all extant genera died out or were killed.  In 1980, Luis Alvarez, a brilliant theoretical physicist whose career was extraordinary, along with his son, Walter Alvarez (a geologist), and Frank Asaro, published an article that describe a sedimentary layer across the world that included a rare element, iridium, usually found in extraterrestrial objects like meteors and comets.  The layer fell right at the geological boundary layer that defines the extinction event, so they proposed that the dinosaurs were wiped out by a huge comet or asteroid.

Today, this accepted as a scientific theory with tons of confirming evidence (although some scientists aren’t fully convinced, though they still propose some natural event).  But at the time, it was ridiculed, and scientific meetings were quite energetic in discussions.  The point is that the impact theory displaced the prevailing scientific theory of the extinction event (well, there were several).  One theory replaced another not by rhetoric or appeals to antiquity (that one theory was around forever) or anything else.  In fact, one scientific hypothesis was replaced by another and eventually developed into a solid theory.

We should be neutral in science, reviewing the evidence, then coming to conclusions.  The Alvarez father-son team provided that, and eventually there was overwhelming evidence with the finding and dating of the Chicxulub impact crater in the Yucatan Peninsula of Mexico.

Using scientific neutrality, vitamin C doesn’t work, not because I have an opinion, but because there is no science supporting its efficacy.  There are some articles that support its use in preventing or treating colds, or megadoses for curing cancer, but those articles are in low-impact (meaning obscure) journals or with poorly designed, or non-blinded trials.  My friendly neighborhood pharmacist was stating that I should be neutral between real science and well, nothing at all.  That’s not balance, that’s a close-mindedness to science and the scientific method.  That’s using opinion as the balance to scientific knowledge.  The only thing that should balance scientific knowledge is more scientific knowledge.

Don’t fall for the trap that you should be “open-minded” or neutral to anti-science or pseudoscience.  Open-mindedness and neutrality are expectations that you will balance real scientific evidence, not treat the rhetoric as if it has equal weight to scientific method.