If there's one thing I'm learning from the crop of evidence-based pregnancy books I've been perusing, it's this: Pregnancy ought to involve a lot more complicated decision-making and less blind rule following. That's because the stuff that gets touted as "must-do" or "can't do" is often, in reality, just one way of interpreting a conflicting and correlation-heavy body of data. Usually there is more than one appropriate, evidence-based decision that you can make, depending on your personal beliefs, desires, and goals. At the Wall Street Journal, Emily Oster does a great job of writing about this, using taboo libations alcohol and coffee as the examples. Read the rest
Alice Bell has a really interesting and challenging essay up that the Guardian talking about apparent contradictions where people tout themselves as being on the side of science with one issue (say, climate change) and are skeptical and not-terribly-accepting of science with other issues (say, GMOs). It's not really something you can boil down to simple hypocrisy, though, Bell says. To do that, you have to ignore the very basic fact that evidence-based decision-making has to take into account more than just scientific data. Instead, economics, social values, legal considerations, and all sorts of other non-science things have to be considered alongside the science. Read the rest
It probably won't hurt, and it could help, says Scott Gavura at Science Based Medicine. But it's also worth taking a closer look at the nuance behind probiotics, too. These are promising medications and a fascinating field of research, but educating yourself on what we do know and what we don't (especially when it comes to purity of various products) is a really good idea. Read the rest
A preggo info site that contains links to Cochrane Reviews, an evidence-based maternity care report, and evidence-based resource links for you and your doctor? Um, yes please. Read the rest
The Tampa Bay Times has done some excellent investigative reporting on the 50 worst charities in America — organizations that took in more than $1 billion over the past 10 years, and gave almost all of that money to their own staffs and professional solicitors. The series explains how charities like this operate and skirt the regulatory system. But if you're feeling TLDR, there's also a PDF that can help you quickly figure out if you're donating to one of these scams. A large portion of the 50 worst is made up of charities devoted to cancer and veterans' issues. Read the rest
It's not just that bad information on the "dangers" of vaccines is working to reduce the number of children getting vaccines — a fact that affects herd immunity. Now, there's evidence that the fake scares (and efforts to debunk them) are getting in the way of scientists publishing real evidence about actual problems with certain vaccines. These aren't the kind of broad "vaccines are poison" claims you're familiar with. Instead, we're talking about legitimate science documenting side effects that are usually very rare, but still have an impact on certain subsets of the population and need to be addressed. Read the rest
The New York Times has a story on problems with the treatment of ovarian cancer that holds lessons for many aspects of modern medicine. The big issue here: Local doctors, even local specialists, might not have the information necessary to properly treat patients who come in with problems those doctors don't have a lot of experience with. And those doctors don't always refer patients to people with more expertise. In a world with constantly changing information, how do you get that information to the people patients are most in contact with? In a world with more and more evidence available, how do you change traditions in the medical community that apply treatments based on "what my teachers did" and "what I've always done"? Big questions here, not a lot of answers. Read the rest
The United States Geological Survey has an interesting FAQ report on dowsing — the practice of attempting to locate underground water with divining rods. It's got some interesting history and comparisons between dowsing and modern hydrology. The part on evidence for and against dowsing, though, is pretty sparse. If you want more on that, The Skeptic's Dictionary has some deeper analysis. The basic gist — what little research there has been suggests the successes of dowsing aren't any better than chance. (Via an interesting piece by Mary Brock at Skepchick about dowsing in the wine industry.) Read the rest
The focus on video games as a source of American gun violence is driving me a bit crazy, so I just wanted to toss some evidence out there. Even though most of you have likely long suspected the two things were not related, you'll be happy to know that science agrees with you. Consider this a helpful kit for forwarding to concerned relatives. Here's a 10-country comparison that found no correlation between video game consumption and gun violence. Here's a Harvard Medical School summary that explains why some people claim video games cause violence, and why the studies behind those claims aren't actually telling us that. And here's a PBS FAQ explaining a lot of the same issues. With violent video games (as with everything else) context matters. Read the rest
Is coffee bad for you or good for you? Does acupuncture actually work, or does it produce a placebo effect? Do kids with autism have different microbes living in their intestines, or are their gut flora largely the same as neurotypical children? These are all good examples of topics that have produced wildly conflicting results from one study to another. (Side-note: This is why knowing what a single study says about something doesn't actually tell you much. And, frankly, when you have a lot of conflicting results on anything, it's really easy for somebody to pick the five that support a given hypothesis and not tell you about the 10 that don't.)
But why do conflicting results happen? One big factor is experimental design. Turns out, there's more than one way to study the same thing. How you set up an experiment can have a big effect on the outcome. And if lots of people are using different experimental designs, it becomes difficult to accurately compare their results. At the Wonderland blog, Emily Anthes has an excellent piece about this problem, using the aforementioned research on gut flora in kids with autism as an example.
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For instance, in studies of autism and microbes, investigators must decide what kind of control group they want to use. Some scientists have chosen to compare the guts of autistic kids to those of their neurotypical siblings while others have used unrelated children as controls. This choice of control group can influence the strength of the effect that researchers find–or whether they find one at all.
Until 2011, Dr. Edzard Ernst was the head of one of the few university departments doing real, unbiased research on the effectiveness and safety of alternative medicine techniques. That's important, because you can't just dismiss weird-sounding stuff out of hand, but you also want somebody other than the practitioners of that weird-sounding stuff conducting research and analyzing the data. Now retired, Ernst recently started blogging, and I wanted to point you to his new home on the Internet. He can be a bit snarky and caustic (especially with chiropractic and homeopathy). But in general he's a fair, reasonable, and knowledgeable source on what works and what doesn't. Definitely worth a bookmark. Read the rest
At The Guardian, blogger GrrlScientist is passing out Nobel Prizes for Quackpottery in the fields of physiology, physics, and chemistry. The prizes are awarded to actual Nobel Laureates who have made deep and long-lasting contributions to undermining their own credibility by latching onto hypotheses they can't back up with evidence and then continuing to promote those hypotheses despite the lack of evidence. It's a nice reminder that scientists are human, and that even very, very smart people are not always rational people. Read the rest
A Yale survey found that 3/4 of Americans believe anthropogenic climate change is really happening. Of course, this comes after an exceptionally hot and drought-y summer and we already know that opinions on climate change oscillate with the weather. To really get a good picture of whether acceptance of climate change is on the rise, we'd have to look at a variety of polls, conducted in different ways by different organizations. And we'd have to look for changes in the trend line over long periods of time, so we know we're looking at an actual, long-term shift. Which all sounds oddly familiar, now that I think about it. Read the rest
Are pesticides helpful things that allow us to produce more food, and keep us safe from deadly diseases? Or are they dangerous things that kill animals and could possibly be hurting us in ways we haven't even totally figured out just yet?
Actually, they're both.
This week, scientists released a research paper looking at the health benefits (or lack thereof) of organic food—a category which largely exists as a response to pesticide use in agriculture. Meanwhile, Rachel Carson's book Silent Spring, which forced Americans to really think about the health impacts of pesticides for the first time, was published 50 years ago this month.
The juxtaposition really drove home a key point: We're still trying to figure out how to balance benefits and risks when it comes to technology. That's because there's no easy, one-size-fits-all answer. Should we use pesticides, or should we not use them? The data we look at is objective but the answer is, frankly, subjective. It also depends on a wide variety of factors: what specific pesticide are we talking about; where is it being used and how is it being applied; what have we done to educate the people who are applying it in proper, safe usage. It's complicated. And it's not just about how well the tools work. It's also about how we used them.
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“It is not my contention,” Carson wrote in Silent Spring, “that chemical insecticides must never be used. I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potentials for harm.
Truth Goggles is a web app that highlights facts in the text of a web page or news story and provides a link that tells you whether or not those facts are true. Read the rest
Over at Download the Universe, Ars Technica science editor John Timmer reviews a science ebook whose science leaves something to be desired. Written by J. Marvin Herndon, a physicist, Indivisible Earth presents an alternate theory that ostensibly competes with plate tectonics. Instead of Earth having a molten core and a moveable crust, Herndon proposes that this planet began its existence as the core of a gas giant, like Jupiter or Saturn. Somehow, Earth lost its thick layer of gas and the small, dense core expanded, cracking as it grew into the continents we know today. What most people think are continental plate boundaries are, to Herndon, simply seams where bits of planet ripped apart from one another.
The problem is that Herndon doesn't offer a lot of evidence to support this idea.
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Once the Earth was at the center of a gas giant, Herndon thinks the intense pressure of the massive atmosphere compressed the gas giant's rocky core so that it shrunk to the point where its surface was completely covered by what we now call continental plates. In other words, the entire surface of our present planet was once much smaller, and all land mass.
I did a back-of-the-envelope calculation of this, figuring out the radius of a sphere that would have the same surface area as our current land mass. It was only half the planet's present size. Using that radius to calculate the sphere's volume, it's possible to figure out the density (assuming a roughly current mass). That produced a figure six times higher than the Earth's current density — and about three times that of pure lead.