Science or Fiction, July 2012

About once a month, I get together with several friends and colleagues for the Lexington Skeptics meetup for dinner and conversation. The topics tend to run from recent science discoveries, pseudoscience controversies, scams and flim flam. Discussion sometimes ranges into religion and politics, but is always polite.

Many people find their way to “scientific skepticism” by way of podcasts like The Skeptic’s Guide to the Universe (SGU) and one of my favorite parts of the SGU podcast (which you should be listening to) is the Science or Fiction segment.

Briefly, the host, Steve Novella asks the co-hosts and guests to pick one fake story from a set of three or four. The others are true, at least in a technical sense. If a true story is turned into a false one and the detail changed is a number, the number is changed to an unreasonably high or low number.

Tonight’s Science or Fiction was a fun one, and led to a discussion of why certain things were possible or not. Read over the following three items, try to pick out the fictional news piece and then click through (or just don’t scroll past the science cat).

  1. Milk thistle slowed the progression of Hepatitis C infection in a placebo controlled clinical trial.
  2. Bacteria are being used to grow spider silk with the tensile strength of black widow spider silk.
  3. Injuries from laser hair removal have led to calls for regulation in Britain.

Let’s take them in reverse order.

“Injuries from laser hair removal have led to calls for regulation in Britain.” The immediate response was that using lasers to kill hair follicles sounded like a risky idea in the first place.

This one is fact. (Quoted from BBC1)

There are no official figures but it is estimated hundreds have suffered burns, mainly women with darker skin.

The British Association of Dermatologists (Bad) says beauty therapists often do not have enough training to perform it safely.

It says if the wrong equipment or settings are used for the client’s skin and hair type, it may not work and they can waste up to thousands of pounds.

The Department of Health says the regulation of laser and IPL hair removal is under review.

A government-backed regulator, the Independent Healthcare Advisory Services, says it is starting a register later this year with a quality assurance symbol launched.

Moving on, “Bacteria are being used to grow spider silk with the tensile strength of black widow spider silk.”

This one is certainly feasible and much of the ground work was already there. Getting bacteria to produce proteins like spider silk monomers is relatively easy. Get the gene, put it on a plasmid, put it in the bacteria, grow and harvest. Getting the silk to form long strands is a little more involved, but is doable. Getting high quality, high tensile strength silk isn’t so simple. (From the Science Daily press release)

Due to their mechanical properties, synthetic spider silks have numerous manufacturing and industrial applications. Of particular interest is the high tensile strength of black widow silk, which is comparable to Kevlar in strength, but is lighter and of a lower density. If scientists could reproduce the mechanical properties of spider spun silk in the laboratory, the material could be used to replace Kevlar, carbon fiber and steel. Increased production of this new biomaterial will have an impact on a wide variety of products where spider silk’s properties are valuable, ranging from bulletproof vests and aircraft bodies to bridge cables and medical sutures.

While scientists have been able to produce spider silk with the same biochemical integrity of the natural fibers for some time, it has remained difficult to mimic a spider’s “post-spin” techniques. The natural post-spin process stretches the fiber in order to align the fiber molecules, and increases the fiber’s tensile strength. To solve this problem, Dr. Craig Vierra from the University of the Pacific developed a technique that removes human variability by using a mechanical actuator. Built by Dr. Vierra and his laboratory group, the mechanical actuator can reliably stretch fibers to a specified length, mimicking the spider’s natural post-spin. Dr. Vierra tells us, “The procedure decreases the variance in the mechanical properties that are seen. Before this procedure, there was a tremendous amount of variation in synthetic fibers.”

Reproducible results in producing quality silk with incredibly useful features? Fact.

That leaves “Milk thistle slowed the progression of Hepatitis C infection in a placebo controlled clinical trial.” This one is the fiction, so if you picked it, congrats!

Milk thistle is commonly used as an alternative medicine for a wide variety of ailments, but when subjected to scientific examination, the results have been mixed, which is typically a sign of a placebo. To be as fair as possible, lets see what the NCCAM has to say. FYI, NCCAM is the NIH center that examines alternative medicine under the most friendly and least skeptical eye possible.

What the Science Says

Previous laboratory studies suggested that milk thistle may benefit the liver by protecting and promoting the growth of liver cells, fighting oxidation (a chemical process that can damage cells), and inhibiting inflammation. However, results from small clinical trials of milk thistle for liver diseases have been mixed, and two rigorously designed studies found no benefit.

  • A 2012 clinical trial, cofunded by NCCAM and the National Institute of Diabetes and Digestive and Kidney Diseases, showed that two higher-than-usual doses of silymarin were no better than placebo for chronic hepatitis C in people who had not responded to standard antiviral treatment.
  • The 2008 Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis (HALT-C) study, sponsored by the National Institutes of Health (NIH), found that hepatitis C patients who used silymarin had fewer and milder symptoms of liver disease and somewhat better quality of life but no change in virus activity or liver inflammation.

Side Effects and Cautions

  • In clinical trials, milk thistle appears to be well tolerated in recommended doses. Occasionally, people report various gastrointestinal side effects.
  • Milk thistle can produce allergic reactions, which tend to be more common among people who are allergic to plants in the same family (for example, ragweed, chrysanthemum, marigold, and daisy).
  • Milk thistle may lower blood sugar levels. People with diabetes or hypoglycemia, or people taking drugs or supplements that affect blood sugar levels, should use caution.

That isn’t exactly a shining review from the people that want it to work more than anything. Well, a new study confirms that HepC infection isn’t affected by milk thistle any more than it is by a placebo. From another Science Daily press release, which links to the full study.

ScienceDaily (July 17, 2012) — Silymarin or “milk thistle,” a popular herbal dietary supplement that many people take for liver ailments, works no better than placebo in patients with chronic hepatitis C infection.

That’s the conclusion of a multicenter clinical trial published in the July 18, 2012 issue of the Journal of the American Medical Association.

“Patients ask me about milk thistle all the time,” said Michael W. Fried, MD, lead author of the study, a professor in the University of North Carolina School of Medicine and director of the UNC Liver Center.

“Now I can tell them with great confidence that taking milk thistle, unfortunately, won’t help for chronic hepatitis C,” he said. “I think this information is very important to help patients focus on other ways to maintain liver health and not rely on ineffective remedies.”

More than half of the conventional medicines available to doctors are plant based or plant derived, and an entire field of pharmacology research, pharmacognosy, is based around finding more medicines from natural sources. Sadly, it looks like milk thistle is not going to be one of them. More bad news, supplements aren’t regulated in any meaningful way in the US, as long as you don’t make any claim towards actually being able to cure or treat an actual disease or disorder, you can do as you like. Just don’t kill anybody famous.

Of particular interest to me is that milk thistle activates a liver enzyme CYP3A4. CYP3A4 is responsible for the metabolism and breakdown of a wide variety of drugs, including drugs used for treating HIV, cancer, a variety of mental health disorders, etc. (just check the wikipedia link for a partial list)

This means that if you are being treated with any of these drugs and take milk thistle, the drugs you are taking to help you don’t get to the levels that they need to be in order to be effective, and if you are taking them to kill cancer cells, it encourages the development of resistance. If it is a painkiller, your levels drop below what you need to control the pain faster. Taking drugs to control a liver infection? If it is on the list, it won’t work as well. And yet, no regulation. Tell your doctor everything you are taking. All of it. Vitamins, herbals, supplements, whatever. You don’t know what will be important.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s