Tag Archives: scientific studies

But Science Keeps Changing Its Mind

24 Oct
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by Benjamen Johnson

By now you’ve probably encountered an acquaintance or family member who will confront you with: “How can you trust science, it keeps changing it’s mind. First coffee is good for you then it’s bad, then it’s good again. Same with eggs or cell phones or juice.” They even might dredge up how scientists were convinced before global warming that the earths climate was actually cooling.

How do you counter this argument, heck, even as a skeptic you may feel that way yourself sometimes? On the surface it does look like science keeps changing it’s mind, but is it reality or is it how it is presented to us?

The first thing to realize is that science isn’t a monolithic institution, it’s a bunch of curious people and organizations trying to find the answers to questions that interest them. There is no one authoritative source that says, “This is the truth.”  The best we have is a consensus, the longer and more thoroughly a topic has been researched the more likely there is a strong scientific consensus, but not always. Plus even a strong consensus can be wrong when new evidence is brought to light.

Next, think about the last time you read an article or saw a news report about something that you have knowledge about. They got some of the facts wrong didn’t they? Now apply that to the rest of the news you consume. Do you really think they only make errors on the stories you know something about? No, just about every story has errors or biases or misquotes, you only notice the stories have errors when you have personal knowledge.

There’s also more subtle ways of confusing the issue. Let’s create a hypothetical series of reports about caffeine. One group publishes a paper that looks at the effect of caffeinated soda on the learning habits of first graders, lets say they find that theres a 30% decrease in attentiveness when first graders consume one or more caffeinated sodas per day as compared to students who consume no caffeinated sodas. What will the headlines read? “Caffeine Makes You Lose Your Focus.” Then another group publishes a study that looks at how well elderly women perform on memory tests . The study finds the women who drink 2 or more cups of coffee a day perform 5% better than women who drink less than 2 cups per day. The headline for this study reads: “Caffeine Improves Your Memory.” In all honesty, five years from now will you even remember the headlines, let alone the details of each study? No, you’ll remember one study said caffeine was bad and another said it was good.

So, lets dig deeper assume both studies were well designed. The studies look at two radically different groups of people, they aren’t studying the same effect, and they aren’t even studying the same beverage. It’s hard to make a meaningful comparison between the two studies. Even assuming the researchers tried to eliminate all the other confounding factors, there always could be some that they missed. Finally these are only single studies — they haven’t been replicated. Replication is a cornerstone of science. If a study can’t be replicated than it’s results are questionable at best.

My last point is the media doesn’t always distinguish between good studies and poorly designed studies. In fact there are many groups that cherry-pick results, using the poor studies and ignoring the good studies to promote their particular agenda. I’m sure you can think of some examples on your own.

UK NHS Report: Supplements — Who Needs Them?

14 Jun

by Benjamen Johnson

Today on the The SkepVet blog, I read that the UK National Health Service just published a report on dietary supplements: Supplements — Who Needs Them? The 34 page report summarizes the current state of research into supplements.

Here’s my layman’s summary of their summary:

  • Vitamin Supplements: Pregnant women and young children might benefit from specific vitamin supplements, eat right rather than supplement.
  • Weight Loss Supplements: Don’t bother.
  • Cold Supplements: Zinc of limited benefit,  Vitamin C and Echinacea don’t bother.
  • Anti-Aging Supplements: Ginko, Ginseng, and Glucosamine — don’t bother.
  • Fish oils: Omega-3 is important, eat fish, be careful supplementing if you are pregnant.
  • Body Building Supplements: We get the protein we need from a normal diet, too much protein is bad, some supplements contain anabolic steroids.

I still think it’s worth skimming the entire report. The report starts with talk about the economics behind the supplement industry, how they are regulated in the UK (still interesting for those of us in the US), and why people take supplements. Then they break the report into different types of supplements, talk about the supplements in that category,  and summarize the key points at the end of each section.

UK National Health Service Report on Dietary Supplements via The SkepVet Blog

Applying Skepticism: Norwex Microfiber Cloths

8 Jun

by Benjamen Johnson

One day my wife brought home an invitation to a Norwex party after picking up our son from preschool. Apparently all the mothers were positively glowing about their microfiber cloth products. They were saying that you didn’t need any cleaning solutions, just this use this silver impregnated microfiber cloth and water. The claim sounded too good to be true; it set my skeptic senses tingling.

The first thing I did was try to find the Norwex website to see exactly what they sold and what they claimed. From their website:

Our line of cleaning products will save you time & money, improve health, and move towards creating a better environment.  Norwex microfiber goes beyond “surface clean” with the innovative use of silver particles integrated into synthetic microfiber cloth ensure:

  • Single-celled micro-organisms such as bacteria, fungi, yeast, and viruses cannot survive or adapt in silver exposure
  • Surface-to-surface cross-contamination is eliminated
  • Rapidly drying cloths prevent bacteria growth in the cloth itself

Cleaning with water only produces a healthy outcome for us and the environment.

Laboratory tests have proven that Norwex antibacterial microfiber reduced bacteria by 99.99% in 24 hours!

Breaking the marketing down line by line I spotted the following red flags:

  • The product makes some big claims.
  • Since when is a virus a micro-organism?
  • They only give laboratory results for antibacterial properties, but what about fungi, yeast, and viruses?

And I asked the following questions:

  • How do the silver particles in the cloth get close enough to kill the “micro-organisms” on the surface?
  • Who performed these laboratory tests, what tests were performed, and what were the actual results?
  • Would you get the same result with a normal Micro-fiber cloth?

The red flags by themselves don’t necessarily mean the claims aren’t true. Many legitimate products inflate their claims and get facts wrong in ad copy — colloquially people call a virus a micro-organism, but technically it’s not. I was a bit more worried about the cherry picking of results. Still there wasn’t enough information from the Norwex website to make an informed decision.

The next thing to ask was, “does the science check out?” Unfortunately, in this case there was so much misinformation about silver on the web that trying to wade through the ton of information to separate out the science from the bunk would have been pointless for somebody who’s not a microbiologist.

The only thing left for me was to try to find other trustworthy people who have written about the product and see if their reasoning held up. Searching for Norwex on Google, I was buried in sites giving the products glowing reviews — all testimonials and anecdotal evidence, no real science. The only place I found people critical of Norwex was a thread in the JREF forums.

On the forums several people asked the same questions I did. One reasonable sounding person, who turned out to be a Norwex consultant, gave the name of a different Norwex website that seemed to explain some of their claims without the marketing speak, but still didn’t address the elephant in the room: are Norwex microfiber cloths any better than normal microfiber cloths or other common cleaning products? One person actually acquired studies Norwex cites and forwarded them on to another forum poster who said he was a biologist. Here’s his summary:

Overall, none of the cited materials say anything valid about the superiority of the Norwex microfiber cloth (or the earlier ACT cloth) over cleaning with an actual cleaner (e.g. bleach). The only testing that they cite was completely non valid for that purpose, and involved dropping a material on a surface and wiping it off. This is entirely unlike actual household or hospital conditions. Based on my review of the supplied documents provided by Norwex, it is my opinion as a biologist that their claims of being able to safely and effectively replace chemical cleaning agents with just water are unsupported.

In conclusion, I never found any real hard evidence to back up the claims Norwex makes, only anecdotes, testimonials, and marketing hype. Until they publish some real peer-reviewed, double blind studies, I would neither spend my money on their product nor trust it to disinfect any area of my home.

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