Feb 23 2018

More on Weight Loss

Whenever I post about the topic of diet or weight management, there is always a lively discussion in the comments. There are also always many comments that are based on ideology, rather than evidence, and the level of emotion is significantly higher than for many similar topics.

I think this is because the topics of food, eating, and weight management seem very personal. Also, everyone has a lifetime of experience with eating, and so everyone feels like their own anecdotal experience makes them an expert (even if they intellectually know they aren’t). The topic is also a setup for confirmation bias – we all have many friends, co-workers, and family with their own dieting experience, and we can even look around and see what strangers are doing and how they look. It is therefore really easy to see the evidence for whatever your opinions are, to have the illusion that your beliefs are confirmed.

To add further fuel to the confirmation bias fire, there are a host of gurus and fake experts out there, and even genuine experts but who only see a slice of the science. There are enough expert and pseudoexpert opinions out there to confirm whatever position we want to take.

For all these reasons dieting is one of the more challenging issues for the average person to find objective reliable information. That is all I am trying to do here, adding my perspective as an advocate for science-based medicine. Interpreting scientific medical data is complicated, and there are lots of opportunities to be mislead. The weight-management literature is particularly complex and heterogeneous, so again, you can support pretty much any position unless you take a really careful look at the literature.

So to follow up my post from yesterday, which prompted a flood of different opinions, let’s take a further look at the evidence.

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Comments: 58

Feb 22 2018

Low Fat vs Low Carb – No Difference

There is a legitimate scientific debate about the optimal proportion of macronutrients (fat, carbohydrates, protein) for weight loss and maintenance. Although I do think there is a strong consensus that the scientific evidence supports the conclusion that the proportion does not ultimately matter (within a range of healthy balance), and that all that really matters is calories in-calories out.

Since weight loss is extremely challenging, even a small edge might be worth knowing about. There are also many basic science reasons to suspect there might be a difference in hunger for different diets, and this will translate into behavior. There are further many health considerations other than just weight and it would be good to know what effect different types of diet have on cardiac and diabetic risk factors.

Unfortunately there is a great deal of confusion and misinformation out there (common for any topic of public interest). One main drivers of this, as I see it, is a self-help industry looking to make billions on the challenge of weight loss by selling one fad diet after the other. Another main driver is the media reporting basic science or preliminary studies without putting them into proper context.

That is why one of the main goals of my science blogging is to emphasize that you cannot reliably make conclusions about interventions from basic or preliminary research. Most new ideas do not work out, and extrapolating from such data is not likely to lead to conclusions which are true. We need the research to develop to the point where we have rigorous clinical trials, testing the ultimate effect in actual people.

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Comments: 39

Feb 20 2018

Superbrain Yoga is Still BS

In 2015 I wrote about a new fad called Superbrain Yoga (SBY – I suggest just reading that article for background). This one is pure pseudoscience – silly and ritualistic movements are used to increase “prana” energy (which is make-believe) and thereby increase mental energy and focus. There is, of course, no credible evidence to support such claims, and no scientific plausibility.

Even though that is an old article, a comment just appeared proclaiming: “Please do some research before you call things a hoax,” followed by four links to alleged evidence that SBY works. One of the links is dead, but the other three refer to studies published in 2016 and 2017. Since my article was written in 2015 it seems unfair to admonish me for not researching future publications.

In any case, it seemed like a good opportunity to update my article on SBY with the new research. As you might have guessed, the articles don’t show what the commenter apparently thinks they do. In fact they are excellent examples of pseudoscience, displaying many of the features I have complained about over the years.

One article looks at alpha wave activity on EEG. The second studies hyperactivity in children with ADHD. And the third looks at memory and attention in children. All three studies share a number of features which makes them less than compelling as evidence. First, they are all published in low-rent journals, such as the Indian Journal of Traditional Knowledge. They may have a slightly biased editorial approach over there at the IJTK. But let’s look at the studies themselves.

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Comments: 4

Feb 19 2018

Brain Plasticity in Infants

A new study looks at the brains of young adults who suffered a stroke in the language center of their brains as infants. They found that the subjects developed normal language, which just relocated to the mirror-image other side of the brain. This is not surprising, and reflects our evolving understanding of how the brain develops and functions.

For most people language localizes to the left frontal and temporal lobes of the brain. Broca’s area in the frontal lobe is involved in speaking, in the subtle motor output necessary to precisely articulate words. Wernicke’s area is in the temporal lobe and is involved in translating words into ideas and ideas into words. The two areas are connected by the arcuate fasciculous. These are the central language areas. There is also surrounding cortex which is necessary for communication between the language structures and other parts of the brain.

For most people the language area is on the left side of the brain. Meanwhile, the mirror right side of the brain is involved with understanding and producing speech intonation – knowing when someone is asking a question or being sarcastic. The right side is also involved with music and singing.

We also know that brains are plastic, meaning they can change the structure of their connections as necessary. People often use a computer analogy when talking about the brain, but the analogy to digital computers is flawed. Computers are hardware that run software, but brains are neither hardware or software – they are wetware, which is both at the same time. The connection of neurons in the brain is where information is stored and processed, and those connections change as a result of the processing, which alters the memory.

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Comments: 1

Feb 16 2018

More Victims of Alternative Cancer Treatments

Every doctor who treats cancer patients can tell you stories of patients who present with cancers too advanced to treat because they were spending their time pursuing alternative treatments. This has also been studied – last year a Yale team published a study showing higher rates of death among cancer patients who choose alternative treatments.

There is now a recent story of a YouTuber who produced videos claiming that a vegan diet and prayer cured her stage 4 cancer, except now she has died from her cancer. Of course, I am sad for her death and that the treatments she sought at the end were not enough to save her. It’s likely that everyone knows someone affected by cancer – it is a scary and often tragic disease. At the same time, we can’t miss the lessons in this story. It is so typical it can serve as an archetype.

What typically happens is that when some people are diagnosed with cancer they search for any possible salvation from their situation. That is understandable. Often there is an initial treatment, such as removal of a solid tumor, or shrinking the tumor with drugs. Some patients may also seek additional intervention, such as alternative treatments or faith healing. At that point they are in the honeymoon phase of the illness – no matter what their ultimate prognosis, their symptoms were likely improved by the initial treatment. They can imagine that they are cured. This is usually the point at which they claim that whatever alternative or faith-based treatment they underwent healed them.

Depending on the type of cancer, some of these patients may have been essentially cured by their initial surgery or treatment. For those who weren’t, a recurrence of symptoms is inevitable. We then may or may not hear about them when the cancer returns and leads to their death.

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Comments: 10

Feb 15 2018

The Neuroscience of Virtual Reality

A couple months ago I received my first virtual reality (VR) headset, and have been experimenting with various games and apps since. (Here is my initial review.) As a neuroscientist, it is a fascinating demonstration of how our brains construct our experience of reality.

What I and everyone who has used my gear has experienced is surprise at how visceral VR can be. It’s just a big video, right, so why do our lizard brains react so strongly? The most dramatic example is an app called “The Plank Experience”. In it you take an elevator up to a high floor in a skyscraper. The door opens to reveal a plank going out over the street far below. Everyone so far is frozen at the moment the doors open and they see the chasm below them. Some can walk out onto the virtual plank, but most people hesitate and at least one person bailed and would not do it.

What is interesting is that when I stepped out onto the plank, I completely 100% knew that I was standing on the carpet in my office, totally safe and at no peril at all. However, the part of my brain that knew I was safe was in conflict with a deeper and more primitive part of my brain that was screaming, “Danger, danger.”  It took an effort of will to overcome the fear, but I could not make the fear go away.

Let me describe one other part of the VR experience and then I’ll discuss what is going on neurologically. Motion sickness has been a major challenge for VR. All of the games and apps I have used so far have an option (usually the default) where if you have to move your character in the VR world you do it by teleporting. You use the control to place an X on the floor where you want to go, and then you are instantly in that location. This type of movement does not produce any motion sickness.

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Comments: 16

Feb 13 2018

New California Initiative – Crank Magnetism in Action

Being involved in skeptical activism for over two decades does provide some perspective. One phenomenon I have noticed is that most pseudosciences and weird belief systems are, at their core, the same. Sure, the details vary, but the underlying errors in logic and thinking are the same. Essentially people make the same mistakes over and over again.

This, in fact, was the original motivation for developing a list of common logical fallacies. We kept encountering the same poor logic time and again and wanted to address the underlying cognitive errors. This is why scientific skepticism is so heavily involved with metacognition – thinking about thinking. There are thousands of fake medical claims out there, for example. Debunking every one is an endless game of whack-a-mole. Better to understand and address the underlying flaw in logic and method that leads to all the medical nonsense.

More recently this phenomenon has been dubbed, “Crank magnetism.” This is the closely related notion that people who believe on type of pseudoscience tend to believe multiple types – they tend to attract each other. The cause of this seems obvious – if your method is flawed, you will achieve the same flawed results over and over.

There may also be different flavors of crank magnetism, although there is a lot of overlap also. For example, there are conspiracy theorists who believe every conspiracy, there are spiritual true-believers who are prone to believing anything mystical, and there are “nature is best” fanatics who are vulnerable to marketing anything as “natural” and fearmongering about “the chemikilz.”

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Comments: 5

Feb 12 2018

Significant but Irrelevant – Study on Correcting False Information

A study from a few months ago is making the rounds due to recent write ups in the media, including Scientific American. The SA titles reads: “Cognitive Ability and Vulnerability to Fake News: Researchers identify a major risk factor for pernicious effects of misinformation.”

The study itself is: ‘Fake news’: Incorrect, but hard to correct. The role of cognitive ability on the impact of false information on social impressions. In the paper the authors conclude:

“The current study shows that the influence of incorrect information cannot simply be undone by pointing out that this information was incorrect, and that the nature of its lingering influence is dependent on an individual’s level of cognitive ability.”

So it is understandable that reporters took that away as the bottom line. In fact, in an interview for another news report on the finding one of the authors is quoted:

“Our study suggests that, for individuals with lower levels of cognitive ability, the influence of fake news cannot simply be undone by pointing out that this news was fake,” De keersmaecker said. “This finding leads to the question, can the impact of fake news can be undone at all, and what would be the best strategy?”

The problem is, I don’t think this is what the study is saying at all. I think this is a great example of confusing statistically significant with clinically significant. It is another manifestation of over-reliance on p-values, and insufficient weight given to effect size.

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Comments: 19

Feb 09 2018

Ontario College Plans Program in Homeopathy

Here we go again.

If you are in a decision-making position at an institution of higher learning than you have a responsibility to understand and protect the academic reputation of that institution. Further, such institutions (many of which, as in this case, are publicly funded) have a responsibility to society, to promote academic standards and legitimacy. At the very least such institutions should not be promoting pseudoscience, or dressing up any nonsense as if it were real.

Georgian College in Ontario has approved funds and plans to open a program that will teach homeopathy as if it is real medicine. Teaching any pseudoscience is an outrage, but when it is medical pseudoscience there is also arguably another layer of malfeasance because the connection to real harm is more direct.

I know this is old territory here, but for review: Homeopathy is a prescientific philosophy-based system based on magical thinking. Its core ideas were never valid, and have never been supported by science. Essentially, homeopathy uses fanciful treatments that are based on silly ideas, such as the personality of the patient, but also “sympathetic magic.” The belief is that homeopathic remedies contain the magical essence of symptoms and can be used to cure those same symptoms.

Then, doubling down on the idea of magical essence, all actual substances are diluted out of existence, so that only the essence remains. Therefore, in reality, only water remains. Homeopathy is literally treating people with magic water created with rituals resembling witchcraft, and without the tiniest bit of scientific legitimacy.

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Comments: 15

Feb 08 2018

Did a Comet Kill the Mammoths

Between 12,800 to 11,500 bp (before present) there was a cold period in North America called the Younger Dryas – named after the dryas flower whose pollen is a good marker for such cold periods. During this time the megafauna of North America, including the Mammoth, largely died out. Along with them went the Clovis culture – a big game hunting culture with distinctive stone points.

What caused this period of climate change and mass extinction?

This is a genuine scientific controversy. One group of scientists believe that the melting glaciers dumped fresh water into the northern Atlantic, temporarily shutting down the ocean currents that bring warm water to North America. Another group think that a comet impact is to blame.

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Comments: 23

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