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Research fails to show that green coffee extract works. It also fails to show travel bans are a good idea for Ebola.

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Research fails to show that green coffee extract works. It also fails to show travel bans are a good idea for Ebola. This is Healthcare Triage News.


Our most popular Healthcare Triage episode is on vaccines and autism, and in it I mention that the Lancet paper that started the whole craze had been retracted from the medical literature. And that such a retraction was rare. That's still true. But it does happen and it did so again this week.

In 2012, a paper was published entitled, "Randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in overweight subjects." It claimed that six weeks of use of GCA, a green coffee extract product, led to an average weight loss of more than eight kilograms. That's impressive. In fact a certain well known TV doctor claimed that it was "magic", "staggering", "unprecedented" and "a miracle pill". Yeah, not so much.

This week the blog Retraction Watch covered the issue. In 2010, Austin, Texas-based AFS paid researchers in India to conduct a clinical trial on overweight adults to test whether Green Coffee Antioxidant (GCA), a dietary supplement containing green coffee extract, reduced body weight and body fat. The FTC charges that the study's lead investigator repeatedly altered the weights and other key measurements of the subjects, changed the length of the trial, and misstated which subjects were taking the placebo or GCA during the trial. When the lead investigator was unable to get the study published, the FTC says that AFS hired researchers Joe Vinson and Bryan Burnham at the University of Scranton to rewrite it. Despite receiving conflicting data, Vinson, Burnham, and AFS never verified the authenticity of the information used in the study, according to the complaint.

These two researchers now claim the study sponsors can't assure them that the data are valid, so they retracted the paper. Bottom line, when something is called a miracle it should be on the front page of every newspaper. And the lead story on every news show. Otherwise, be skeptical. Consider conflicts of interest. Think about the source. Remember that not all research is rigorous. And never, ever forget that the plural of anecdote is not data.

Our second story is about Ebola. First, the good news. It appears that both Spain and the United States are getting a handle on their outbreaks. In even better news both Senegal and Nigeria have successfully contained and ended their outbreaks. The bad news is that much of West Africa still needs a lot of help. But you know what won't work? Travel bans.

In a recent piece at, Julia Belluz and Steve Hoffman went through the evidence on travel bans to contain epidemics. Their arguments are pretty compelling. First of all let's look at what happened with HIV/AIDS. The US only lifted its Entry, Stay and Residents restrictions after President Obama came into office. The disease still became a pandemic in the 1990s. And a review article published in 1989 found that travel restrictions were expensive, hard to enforce, discriminatory, and harmful. One of the biggest problems was identifying people traveling who might have the disease. That same problem exists with Ebola.

Their second argument uses a natural experiment. After September 11th 2001, temporary flight bans went in to place all over. They had pretty much no impact on the flu season. It delayed it and actually led to it being prolonged. Oddly enough flu deaths spiked that year. There's no way to know if that was due to the travel ban, but the ban certainly didn't reduce deaths.

A study published in 2006 in the Proceedings of the National Academy of Sciences, in the United States, showed that travel restrictions wouldn't work for avian flu. Another study in PLoS One showed that travel restrictions put in place in 2009 to prevent the spread of swine flu, didn't work. A Canadian study showed that airport screening for SARS in 2003 caught literally zero cases.

Now it's likely that travel bans will have some effect. They'll make the epidemic worse in Africa. Travel bans make it harder to get supplies and help to those who need it. They'll hurt the economies of affected countries. They'll make it potentially more likely that the epidemic will rage out of control in West Africa. Which would put the rest of the world in increased risk.

Travel bans make for good theater. They sound like they make sense. But they may do more harm than good. We can do better.