May 13 2014

Resveratrol – Reason for Skepticism

Dr. Oz recommends resveratrol as a supplement to reduce inflammation and protect the heart. On his website you will find:

While resveratrol has been recommended for fighting the physical effects of aging, a brand new study shows it reduced inflammation of the heart in the study’s participants by 26%. Taking one 500 mg capsule of resveratrol daily with food will help you maintain a strong, healthy heart.

How evidence-based is this recommendation? At present we have preliminary in vitro and in vivo studies showing that resveratrol has interesting biological effects that are potentially beneficial, particularly in heart disease. There are some short term human studies as well.

The question is – how predictive are such early promising research results to later long-term clinical studies? I have written many times arguing that the answer is – not very much. There is researcher bias, exploiting degrees of freedom, and publication bias to contend with, all favoring false positive results in the literature.

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May 12 2014

Correlation and Causation

Every skeptic’s new favorite website is Spurious Correlations. The site is brilliant – it mines multiple data sets (such as causes of death, consumption of various products, divorce rates by state, etc.) and then tries to find correlations between different variables. The results are often hilarious.

The point of this exercise is to demonstrate that correlation does not necessarily equal causation. Often it is more effective to demonstrate a principle than simply to explain it. By showing impressive looking graphical correlations between phenomena that are clearly not related (at least proposing a causal connection superficially seems absurd.), it drives home the point that correlation is not enough to conclude causation.

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May 08 2014

After the Afterlife Debate

The debate hosted by Intelligence Squared on the proposition – Death is not Final, was a lot of fun. Of course, I am pleased with the outcome, as I think my partner, Sean Carroll, and I performed well, and in the end we won the final audience vote.

Off stage I found Raymond Moody to be a very nice guy. He is a philosopher of logic, and in general seems to understand a great deal about skepticism. He rejects the pseudoscience of ESP and other paranormal claims. Yet – he seems to have a soft spot for claims of the afterlife. Not surprising since he wrote the book on NDEs in the 1970s.

Eben Alexander was also very friendly, as I expected given his interviews and everything I have read about him.

Although interesting, debates are terrible venues for carefully dissecting the evidence. There is no time to look up references and check claims. Two times Eben Alexander and I came to an “impasse” and had to simply move on.

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May 06 2014

Afterlife Debate


I will be involved in a debate Wednesday evening (May 7th) at the Kaufman center in New York.

The debate will be from 6:45 to 8:30pm.

The debate is hosted by Intelligence squared, which hosts a series of such debates. While tickets are sold out, the debate will be live streamed. I have embeded the stream below, or you can see the stream here: http://goo.gl/WNV6nQ 

The specific topic is “Death is not Final”

Against this proposition will be me and Sean Carroll. Sean is  a physicist, so he will cover the physics angle, while I will cover the neuroscience.

For the proposition will be Eben Alexander, author of Proof of Heaven, and Raymond Moody, author of Life after Life.

The evening promises to be very interesting, so please tune in.

You can view the live stream of the debate here:

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May 05 2014

David Katz on Evidence in Medicine

David Katz is a fellow physician at Yale, and he is also a strong proponent of so-called “integrative medicine.” He has written a recent commentary at the Huff Po, defending the integrative approach. He writes:

Integrative Medicine — a fusion of conventional and “alternative” treatments — provided patients access to a wider array of options. So, for instance, if medication was ineffective for anxiety or produced intolerable side effects, options such as meditation, biofeedback, or yoga might be explored. If analgesics or anti-inflammatories failed to alleviate joint pain or produced side effects, such options as acupuncture or massage could be explored.

His basic argument is this – when we lack strongly evidence-based options, we need to explore not-so-evidence-based options, for the good of our patients. Mainstream medicine is not that evidence-based either. And – mainstream medicine relies on money-driven research, which is biased against integrative approaches.

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May 02 2014

Framing Bias

Let’s say you need a surgical procedure and the surgeon tells you there is a 98% survival rate with the procedure. How would you feel about that? What if she told you there was a 2% mortality rate? Would you feel the same way? Probably not, according to years of psychological research.

This is known as framing bias, just one more of the many ways in which our brains are biased in the way we evaluate information. The two scenarios above are identical, but statistically people will make different decisions based upon how the information is framed. We generally respond better to positively framed information (98% survival) than to negatively framed information (2% mortality).

The framing effect is often exploited by those who are deliberately trying to manipulate our reactions. Politicians, for example, can talk about employment rates or unemployment rates. Events can give you an early-bird discount or a late registration penalty. Products can have 4% fat or be 96% fat free.

Framing is another way in which we construct our picture of realty, by deciding what information is important.

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May 01 2014

Can Diet Cure MS?

I always find it fascinating to read an opinion piece that, from my perspective, is entirely wrong. In general I like to confront views that differ from my own; it is a great opportunity to probe and understand your own position better. I also find it fascinating to dissect the process that could lead someone to a demonstrably wrong position. Are they just misinformed, is their logic flawed, or are they overwhelmed by bias and ideology?

Usually it is the result of all three of these things in a self-reinforcing echochamber, an ideologically pleasing narrative propped up by confirmation bias.

A number of people have sent me links to this opinion piece, and other articles about Dr. Terry Wahls, who claims to have cured her own multiple sclerosis (MS) with diet alone. She advocates a paleo-style diet to cure whatever ails you. The evidence for this claim – zippo.

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Apr 29 2014

Neuromorphic Computing

Kwabena Boahen and other engineers at Stanford University announce that they have developed a computer chip modeled after the human brain. They call the technology “neuromorphic” and their current device the neurogrid. They say it can simulate 1 million neurons in real time, a feat that would otherwise require a super computer.

The idea is that the human brain is much more powerful and energy efficient than our current computers. A mouse brain can process information 9,000 times faster than a computer simulation of its functions, while using much less energy.

The article does not explicitly state it, but I suspect these numbers are for virtual simulations – in other words, we are not building mouse brain circuits in silicon, we are using standard digital computer to simulate the mouse circuits in software. Virtual simulations are much less efficient (about an order of magnitude) than dedicated circuits.

Even still, the neurogrid looks like a huge advance even over building dedicated brain circuits using standard digital chip technology.

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Apr 28 2014

Dueling Narratives on Organic Farming

There are many public debates raging that are essentially dueling narratives, both sides claiming to have science, evidence, and logic on their side. It always fascinates me when two groups can look at the same evidence and come to opposite conclusions. Is man-made climate change a real danger or all hype? Are alternative medicine treatments a revolution or a scam? Is GMO our best hope for sustainable agriculture or a looming health menace? Is organic farming useful or just marketing the naturalistic fallacy?

These binary choices are a bit of a false dichotomy, but not entirely, as people do tend to fall into one or the other camp. The narratives then tend to polarize the two sides with self-reinforcing echochambers of opinion and information.

I am also not suggesting that in each of the topics above the two sides are symmetrical or equally valid. Alternative medicine, for example, is a scam – it is the explicit creation of a double standard in order to market treatments that fail the test of scientific validity.

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Apr 25 2014

Prebiotic Earth

One of the great scientific mysteries is the specific processes and pathways that led to the first living organisms on earth. This is not mysterious in that we don’t know how it could have happened, it’s just that it is extremely difficult to reconstruct how is actually did happen. Chemical reactions don’t fossilize, and so understanding a complex process that likely took millions of years to unfold billions of year ago is a bit challenging.

Researchers have mostly had to rely on plausibility studies – experiments that show how prebiotic evolution could have happened and extrapolating from data on early earth conditions. More progress has been made with this type of research. The title of the paper says it all – Non-enzymatic glycolysis and pentose phosphate pathway-like reactions in a plausible Archean ocean. (Markus A. Keller, Alexandra V. Turchyn, Markus Ralser)

The researchers showed that, in conditions based upon published literature about the early prebiotic ocean, certain metabolic pathways central to life could happen spontaneously and without the presence of enzymes. That last bit is critical – enzymes are proteins that act as catalysts, which are substances that make a chemical reaction happen faster. Enzymes are critical to life, as the biochemical reactions of life would occur at too slow a rate without them.

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