Epidemiology

How Many Calories for a Dollar?

Michael Pollan, as always, making perfect sense:

Now watch Will Allen on urban farming…

Egyptian Mummies Yield Ancient Secrets of Good Journalism

This is based on an LA Times article here

What strikes me most is how athlerosclerotic the science itself is.  Or perhaps it’s just the reportage?

The opening line of the article is “CT scans of Egyptian mummies… show evidence of… hardening of the arteries, which is normally thought of as a disease caused by modern lifestyles….”  One of the researching cardiologist draws this conclusion: “Perhaps atherosclerosis is part of being human.”

The LA Times reporter covering the story (Thomas Maugh) rightly points out at the end, “The high-status Egyptians ate a diet high in meat from cattle, ducks and geese, all fatty.”  Which of course entirely negates the hypothesis of heart disease being part of the natural human condition.

It’s clear why the researchers — both cardiologists — would want ancient evidence to support the notion that heart disease is normal.  But the fact is that the preponderance of evidence around the world in epidemiology as well as cardiology indicates that …

Inoculating Against the Anti-Vaccine Meme

The debate over vaccination is raging (c.f. Wired article) and it smacks of one of those conundrums that is unlikely to get resolved by scientific inquiry.  I offer the following hypothesis and a way out of the dilemma.

Hypothesis: Vaccination is something that is good at the societal level but bad at the individual level.  That is, it is a tragedy of the commons.  You want all your neighbors to get vaccinated so they don’t pass on the germs to you, but there is enough risk from the vaccination process (at least for certain ones) that you’d rather not do it yourself.

The mathematics of the commons tragedies suggests that there are two ways out.   One is to change the payout/incentive structure, in other words, make the vaccine’s less risky to the individual, or at least change the perception of the individual risk (as the Wired article suggests).  The problem with manipulating perception is, what if you’re wrong?  The marketplace of ideas …

Rafe Issues Challenge to Statin Industry

I have been trying to get the straight scoop on whether statins actually decrease mortality and morbidity in a significant way and I haven’t been able to find any real evidence that they do.

If you ask a cardiologist it’s clear that they believe unequivocally that statins work, mostly because they see what statins to do blood cholesterol levels.  But remember, cholesterol numbers in and of themselves do not matter.  They are a proxy variable for cardiovascular health.  Plaque buildup matters.  At one time blood cholesterol numbers were the only non-invasive indicator we had of plaque buildup, but that’s not true anymore.  However, drug companies are highly incentivized to prove that statins improve health.  So they fund lots of studies.

Notwithstanding the systemic bias when there are profit motives and publication motives, we can turn to these studies and see if statins actually work.  The best way to remove bias is to look at large-scale meta-analyses, like this one.  If you simply read the …

Should You Use Sunscreen?

This is a very complex topic, as the following talk suggests:

The main takeaways from this that I got are:

  1. Cancers for which sunlight deficit is a risk factor are orders of magnitude more prevalent than the few for which overexposure is a risk factor.
  2. People who are using sunscreen regularly are precisely the ones who shouldn’t be.
  3. We should be very careful and sparing about recommending sunscreen usage or sun avoidance, and always temper such advice with the tradeoffs of not getting enough sunlight.

As someone who wonders on a regular basis whether the public has the right information to make informed decisions about health-related tradeoffs, I am curious… does the above strike you as surprising?  What do you currently do regarding sun exposure, and are you likely to change anything based on the above?  What do you think the overall message that reaches the masses is regarding sun exposure?…

Celiac Disease on the Rise

According to a new report in Gastroenterology (July 09), Celiac Disease is now 4 times more common in the US than it was during the 1950’s. The disease results from an intolerance to the protein gluten, found in wheat, barley, and rye.  When celiac patients consume gluten, they suffer an inflammatory reaction within the small intestine that can lead to a host of manifestations, including abdominal pain, diarrhea, weight loss, anemia, infertility, malnutrition, and premature osteoporosis.  It can develop at any age and is frequently misdiagnosed or undiagnosed because of its non-specific symptoms.  Based on this new evaluation, about 1 in 100 people have it and many are not aware.  Anyone with chronic gastrointestinal complaints or any of the features listed above, should be screened for this disease.  A simple blood test can determine the diagnosis in most cases.  Treatment entails lifelong adherence to a gluten-free diet.  The “silver lining” for folks diagnosed with Celiac disease is that it largely and forever commits them to

Something Fishy About Mercury

Here is a fascinating discussion on NPR’s Forum from earlier this year on the subject of mercury and fish:

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If you’ve listened to this the whole way through (which you should), I’m curious as to how it will affect your habits, if at all.  And why?…

Violence on the Decline

From Monday’s Washington Post:

The District, New York and Los Angeles are on track for fewer killings this year than in any other year in at least four decades. Boston, San Francisco, Minneapolis and other cities are also seeing notable reductions in homicides.

Full article is here, in which more sensible police approaches are given credit for the decline.…

Early Detection: better late than never

Here is the scariest image in all of cancer:

cancermortality

Graph from Fortune Magazine article.

Best Talk of Pop!Tech '08

The reason I like this talk so much (besides that it’s well-presented) is that it introduces us to the idea of invisible etiology.  Such a powerful concept, one that I feel has the power to help us solve so many mysteries, once we take it seriously.

Something that I’ve been thinking about lately: does homelessness have an invisible etiology (or etiologies), and if so, what is it?…

Behavior and Emotions as Virus

We’ve talked about obesity as a virus and violence as a virus, both well-supported by the research.  Now there’s happiness as a virus.  Hardly a surprise, but I guess for new paradigms to become the accepted basis for organizing scientific thinking, they first have to become banal.  So let’s bring it on, what’s the next human behavior or emotion that will be featured in a “surprising”study showing a viral etiology?

hat tip: Daniel Horowitz

Invisible Etiology

One of the most poignant moments of this year’s Pop!Tech for me — which, BTW had many — was Gary Slutkin’s talk on the idea of violence being a virus.  You may have heard about his work in stopping violence in Chicago in a NY Times Magazine cover article earlier this year.  The premise is simple: if you throw out what you think you know about violence and just look at the etiology of how it manifests in the world, you find incredible similarities to the etiology of microbial viruses.  This includes not only how it spreads from person to person, but also the larger epidemiological patterns, and importantly, how it can be stopped via interventions which logically follow from the hypothesis that violence is a virus.  Not that violence is caused by those invisible critters we call viruses, but rather that violence itself is a virus.…

The Socioeconomics of Cancer

Pop Quiz: Which is a bigger determinant of cancer mortality in America, being poor or being black?

According to Dr. Harold Freeman of the National Cancer Institute, poverty is the bigger factor today, but it hasn’t always been so:

Autism and Mercury

A recent study funded by the Centers for Disease Control and Prevention (CDC) in Atlanta claims that thimerosal, a mercury-based preservative used for many years in vaccines, is “not associated with problems in speech, intelligence, memory, coordination, attention, or other measures of childhood development.” For those unaware of the thimerosal controversy, it has been claimed by many that it causes or is a factor in the development of autism. Michael Goldstein, vice president of the American Academy of Neurology said of the CDC study that it was, “enough to convince me that this small amount of mercury … was not harmful to the children.”

However, there is a glaring problem with this study. While it seemed comprehensive with respect to thimerosal exposure, it apparently did so by combing health plan records, not by attempting to measure levels of mercury in the actual bodies of the children or their mothers during pregnancy.…

Is Obesity Contagious?

Science News reports that a 2005 study of obese and normal-weighted people found that “30% of the obese group showed signs of previous adenovirus-36 infection, while only 11 percent of the lean group did”. Recent research showed that the virus induces long-term changes in how stem cells develop, causing some that were slated to form bone cells to turn into fat cells instead. Researchers are quick to point out that you shouldn’t avoid fat people for fear of infection because the infectious phase only lasts a few weeks, and would have ended long before obesity set in.…