Archive for the 'Science and Medicine' Category

Feb 26 2018

The Efficacy of Antidepressants

A new major study finds that antidepressants are effective for the acute treatment of major depression. The study is considered a definitive systematic review and meta-analysis including 522 trials comprising 116,477 participants. This includes unpublished data from pharmaceutical companies, to address the concern that some negative data was being hidden.

In the study all 21 antidepressants studied were more effective than placebo, ranging from 1.37 times as effective to 2.13 times as effective.

This is not surprising to anyone familiar with the evidence – it is, in fact, just a review of that evidence. However, many in the public might be confused because these results seem to contradict previously reported studies that purport to show that for many patient antidepressants are no more effective than placebo.

This confusion, however, is largely due to poor reporting. The key factor that is often missed is the severity of the depression. Often I hear people claim that, “Antidepressants have been shown not to work for depression.” But that is not a meaningful statement because you cannot scientifically refer to the evidence regarding “depression” without qualifying “mild to moderate” vs “severe” depression. That detail often gets dropped in mainstream reporting, and therefore the public consciousness.

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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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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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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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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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Jan 08 2018

Nitrite Free Bacon

A Northern Irish food company, Finnebrogue, is offering what it calls “Naked Bacon” – free from chemical preservatives that contain nitrites. But would such bacon actually be more healthful? And what is the deal with nitrites in food?

Sodium nitrite (NaNO2) is a salt containing sodium, one nitrogen, and two oxygen atoms. Nitrate is similar but contains three oxygen atoms (NaNO3). Nitrites are oxidized to nitrates when exposed to the air. Nitrates can also be converted into nitrite in the GI tract. This is why we often talk about the two in food interchangeably.

Sodium nitrite serves a critical function in some foods – it is a good preservative that inhibits the growth of bacteria, specifically C. botulinum, the bacteria that causes botulism. It is therefore incredibly important to food safety, and removing it from meat products could therefore have the unintended consequence of increasing food poisoning.

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Dec 18 2017

CDC Word “Ban”

I received a flood of e-mails over the weekend pointing me to reports that the CDC is banned from using seven words or phrases in their upcoming budget proposals. They are not George Carlin’s famous “seven dirty words” you can never say on television.  Rather they are: “vulnerable,” “entitlement,” “diversity,” “transgender,” “fetus,” “evidence-based” and “science-based,” according to the Washington Post, who broke the story.

First let’s discuss the status of these reports – they are not official public statements from the Centers for Disease Control (CDC), the HHS (department of Health and Human Services) or the Trump Administration. They are anonymous reports from CDC officials who were present during a meeting in which the seven unwanted terms were discussed. Apparently this report was confirmed with several people who were present.

CDC Director Brenda Fitzgerald has pushed back against these reports without straight-up denying them.

“I want to assure you there are no banned words at CDC. We will continue to talk about all our important public health programs,” CDC  said in a Facebook post. “I want to assure you that CDC remains committed to our public health mission as a science- and evidence-based institution. As part of our commitment to provide for the common defense of the country against health threats, science is and will remain the foundation of our work.”

Meanwhile the HHS stated the reports were a “mischaracterization.”

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Dec 07 2017

Alternative Medicine Kills

If the best available evidence is used to determine which treatment strategy for a serious illness has the best survival, than any “alternative” to this evidence-based treatment should, by definition, have a lower survival.

That is a simple and straightforward fact. You have to believe in some twisted conspiracy theory to avoid the obvious conclusion.

But good scientists like to dot all their “i”s and cross all their “t”s. In August Yale researchers published a study in which they looked carefully at the outcomes of cancer patients treated with conventional treatments vs those who opted for so-called alternative treatments. They only considered patient who used alternative treatments instead of proven treatments.

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Dec 01 2017

Liberation Procedure for Multiple Sclerosis – The Final Chapter?

In 2009 an Italian neurosurgeon, Paolo Zamboni, published a controversial article in which he claimed that patients with multiple sclerosis (MS) suffered from blockage in the veins that drain blood from the brain, that this correlation was strong and the pattern suggested a causal relationship. He called his newly identified condition Chronic Cerebrospinal Venous Insufficiency (CCSVI). His article concluded:

CDMS is strongly associated with CCSVI, a scenario that has not previously been described, characterised by abnormal venous haemodynamics determined by extracranial multiple venous strictures of unknown origin. The location of venous obstructions plays a key role in determining the clinical course of the disease.

I first wrote about the resulting controversy in 2010. At the time I concluded that there was good reason to be skeptical, that there were many “red flags for crankery”, but that further research should be done to put the question to bed. There were many reasons to be skeptical, not the least of which is that an entirely vascular cause of MS went against decades of research showing that MS is an autoimmune disease. In that first article I also wrote:

Then one of two things will happen: either the new idea or treatment will fade, becoming little more than a footnote in the history of science, or a subculture will persist in believing in the treatment and will dismiss contrary evidence and mainstream rejection as a conspiracy. Which course the new idea will take seems to depend largely on the original scientist – if they accept the new evidence and abandon their claims, it will likely fade. If they refuse to give up in the face of new evidence, then a new pseudoscience will likely be born.

Well, here we are 8 years after Zamboni’s original publication. How has this drama played out?

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Nov 17 2017

The Ethics of Head Transplants

sergio-canaveroNewsweek, who has been following the story of Italian Neurosurgeon, Sergio Canavero, now reports: “Human Head Transplants Are About to Happen in China: But Where Are the Bodies Coming From?”

I have already discussed the scientific aspects of this claim. They are highly implausible and I doubt that such a transplant is about to happen at all. If it does I predict it will be a dismal failure, and ethically dubious. First, I have to reiterate, that it is far more accurate to call such a procedure a body transplant. The head donor will wake up with a new body. The body donor is, I suspect, dead.

There are three basic hurdles that need to be overcome in order to have a successful body transplant – the surgical attachment, suppression of rejection, and regeneration of the attached neurological tissue. Given that Canavero is a surgeon, I suspect he is excited about the first issue. He may think he has made some advances because he improved his technique for making the attachment. This was never, however, the primary hurdle.

We are already making great advances with organ transplantation and controlling rejection. However, this is still a huge issue. Donor and recipient have to be closely matched, and lifelong drugs are required. Still, the amount of tissue being transplanted here will be a challenge. It opens up, for the first time, the possible effects of tissue rejection on an entire brain. While this is a significant hurdle, our current treatments mean it is not necessarily a deal breaker (it might be, but research would be needed to see).

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