Category: Health

The pregnancy wars

By Razib Khan | August 21, 2013 1:43 pm

I don’t currently have time to read Emily Oster’s Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong and What YouReally Need to Know, but I am very excited that it came out. Having had a pregnant wife and becoming a parent has made it clear to me that much of ‘conventional wisdom’ in regards to both parenting and pregnancy are socially enforced norms which have marginal empirical grounding (this is clear when you look at the huge variation in cross-cultural expectations even in developing societies). So I’m glad that Oster is pushing this issue in a somewhat more rational and hard-headed fashion that has previously been the case (i.e., some of people who I think have good ideas about skepticism of the idea that every pregnancy is a medical emergency waiting to happen at any moment, also try to sell you on ‘alternative medicine’ more generally). It doesn’t help that she’s within the penumbra of University of Chicago’s academic celebrity.

But the reason I’m posting right now is that the book’s Amazon page is a case in point in regards to the intersection between pregnancy and the culture wars. Of 50 reviews as of this writing 20 give it five stars, 2 give it two stars, and 28 give it 1 star!

MORE ABOUT: Health, Pregnancy

Circumcision rates: averages which deceive

By Razib Khan | July 30, 2013 2:40 am

Update 2: No longer accepting comments on this post. Please stop submitting. Thanks.

Update: Due to the vociferous and emotive nature of many comments, I am not publishing over half submitted on this post. Just so you know your chances…

One thing that I have read repeatedly is that circumcision rates in the United States have fallen over the past generation. For non-Americans in the readership, yes, American males are customarily circumcised even if they are not from a religious or cultural tradition where this is the norm (i.e., they are not Muslim, Jewish, or East or West African). For Americans, yes, circumcision has nothing to do with Christianity (something that would be obvious if more Americans actually read the New Testament, instead of just quoting selective passages from it). But looking more closely at the data it seems that the decline in circumcision is predominantly a function of its collapse as a normative practice in the western states!

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MORE ABOUT: Circumcision

Chemicals and cancer, signal and noise

By Razib Khan | July 2, 2013 7:07 pm

Pancreatic cancer tissue

George Johnson is out with a new book, The Cancer Chronicles: Unlocking Medicine’s Deepest Mystery, and is also now at the center of a host of controversies due to some of his conclusions after years of research and writing. You can keep track of the volleys back and forth at his blog, Fire in the Mind. But I want to you pay close attention in particular to a new piece in Discover (print edition), Prehistoric Times: The idea that cancer is a modern disease is a common misconception — one that the fossil record reveals to be untrue. Here’s the big bold assertion: correcting for the greater longevity of modern people the rate of cancer is no higher today than it was in the human past. This is a shocking claim, and bound to cause controversy.

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Non-invasive first trimester testing for Down syndrome

By Razib Khan | June 9, 2013 9:45 pm

Fetus at ~12 weeks

I am going to get back to the eugenics debate at some point, but it is hard to motivate myself. This is due to a combination of complacency and sanguinity. Many of those who use eugenics as a “scare word” or are “very concerned about it” don’t really seem to get past generalities when it comes to the present situation (i.e., there is detailed exploration of past atrocities, and some exploration of rather unrealistic scenarios, such as occurred with the “Chinese eugenic” story, but little concrete engagement with realities such as the high abortion rates for positive tests for Down syndrome). In more crass and intellectually vapid discussions liberals and conservatives tend to use eugenics as a term of selectively useful instrumental rhetoric, a bludgeoning instrument only in the mindless screaming discourse.

Meanwhile, we have advances like the whole genome sequencing of second trimester fetuses. This is still basic science, but in genomics basic science is translated really fast to the consumer market. I’m ~90 percent sure my daughter will have a 10 x whole genome sequence by the end of 2014 (I might even get her parents in on the game for a trio). So, submitted for your interest are two papers on first trimester noninvasive screens for Down syndrome due to aneuploidies (and other syndromes). Non-Invasive First Trimester Blood Test Reliably Detects Down’s Syndrome and Other Genetic Fetal Abnormalities:

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Obesity as morality and health

By Razib Khan | May 28, 2013 11:33 am

Normally I don’t post “read the whole thing,” but this really applies in the case of Virginia Hughes’ new piece in Nature, The big fat truth. The ‘counter-intuitive’ finding is that in some age groups the slightly overweight have the lowest mortality rates. This is not totally surprising news, though there has been a long term debate on whether this is an artifact or not. Hughes notes:

If the obesity-paradox studies are correct, the issue then becomes how to convey their nuances. A lot of excess weight, in the form of obesity, is clearly bad for health, and most young people are better off keeping trim. But that may change as they age and develop illnesses.

The key here is that one-size-fits-all public health jeremiads are probably counter-productive in the long term. The question isn’t whether to present nuances, it is how to do it well. It doesn’t seem the status quo is working out so well after all.


On genetic privacy

By Razib Khan | March 29, 2013 8:35 pm

Larry Moran has a post up, Who Owns Your Genome?, where he mentions me apropos of the HeLa genome disclosure:

In my opinion, there is no excuse for publishing this genome sequence without consent.

Razib Khan disagrees. He thinks that he can publish his genome sequence without obtaining consent from anyone else and I assume he feels the same way about the sequence of the HeLa genome [Henrietta Lacks’ genome, and familial consent].

In response to Larry, I don’t have a definitive opinion about the HeLa genome disclosure in terms of whether it was ethical to release it or not. “Both sides” have positions which I see the validity of. I think ultimately the root issues really date to the 1950s, not today, and they don’t have to do with personal genomics as such. Also, I’d recommend Joe Pickrell’s post, Henrietta Lacks’s genome sequence has been publicly available for years.

Larry also has a question in the comments:

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MORE ABOUT: HeLa, Personal genomics

Putting a stop on the biological clock

By Razib Khan | October 25, 2012 2:41 am

Egg freezing enters clinical mainstream:

Egg freezing is no longer an experimental procedure, according to the American Society for Reproductive Medicine (ASRM), which on 22 October issued new guidelines on the controversial practice. The change in policy is expected to accelerate the growth of clinics that offer egg freezing to women who face fertility-damaging treatment for cancer or other conditions, and to women wishing to delay having a baby — although the society stopped short of endorsing the procedure for that purpose

You can read the full guidelines, with caveats, online. Last I checked this costs on the order of $10,000. Nothing to sneeze at, but definitely not insane when you consider how much money many couples spend on fertility technologies when women are between 35 and 40.

And of course I recommend freezing sperm too. That’s far less costly.

MORE ABOUT: Fertility

The moral measure of bad teeth

By Razib Khan | September 29, 2012 9:57 pm

Recently I was at the dentist and I was told that because I did not have any caries at this age, I would probably not have to worry about that in the future (in contrast, I do have some issues with gingivitis). I wasn’t surprised that I didn’t have caries, I have no great love of sweet confections. I had chalked up my evasion of this dental ailment to my behavior. To make a long story short my dentist disabused me of the notion that dental pathologies are purely a function of dental hygiene and diet. Rather, he explained that many of these ailments exhibit strong family and ethnic patterns, and are substantially heritable. My mother did suffer from periodontal disease a few years back, and that has made me much more proactive of my own dental health.

As someone who is quite conscious of the power of genetics, I was quite taken aback by this blind spot. I realized that not only did I attribute my own rather fortunate dental health (so far) to my personal behaviors, but, I had long suspected those with dental issues of less than optimal habits. Obviously environment (e.g., high sugar diet) does matter. But apparently a great deal of the variation in the trait is heritable. If you are still curious, here’s a paper which might interest you, Heritable patterns of tooth decay in the permanent dentition: principal components and factor analyses.

MORE ABOUT: Heritability

Being fat is like being gay (?)

By Razib Khan | August 31, 2012 12:21 am

Anti-obesity: The new homophobia?:

Consider the many parallels between the treatments advocated by those who claim being gay is a disease, and those being pushed by our public health establishment to “cure” fat children and adults of their supposedly pathological state.

The advocates of so-called conversion or reparative therapy believe that “homosexuality” is a curable condition, and that a key to successful treatment is that patients must want to be cured, which is to say they consider same-sex sexual orientation volitional. These beliefs mirror precisely those of the obesity establishment, which claims to offer the means by which fat people who want to choose to stop being fat can successfully make that choice.

Those who seek to cure homosexuality and obesity have tended to react to the failure of their attempts by demanding ever more radical interventions. For example, in the 1950s Edmund Bergler, the most influential psychoanalytical theorist of homosexuality of his era, bullied and berated his clients, violated patient confidentiality and renounced his earlier, more tolerant attitude toward gay people as a form of enabling. Meanwhile, earlier this year a Harvard biology professor declared in a public lecture that Mrs. Obama’s call for voluntary lifestyle changes on the part of the obese constituted an insufficient response to the supposed public health calamity overwhelming the nation, and that the government should legally require fat people to exercise.

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The eternal question of calorie restriction

By Razib Khan | August 29, 2012 9:22 pm

There’s a lot of buzz about a new paper in Nature (yes, I know there’s always buzz about some Nature paper or other), Impact of caloric restriction on health and survival in rhesus monkeys from the NIA study. You’ve probably heard about calorie restriction before. For me the issue I have with it is that people who are very knowledgeable (i.e., researchers who know a great deal abut human physiology, etc.) have given me contradictory assessments of this strategy of life extension. But it’s not totally crazy, there are serious scientists at top-tier universities who practice calorie restriction themselves. This isn’t the final word, but I wouldn’t be surprised if it is going to take decades for it to resolve itself for humans specifically (because some people will always be, and perhaps rightly, extrapolating from short-lived organisms to humans when it comes to modulations of lifespan in the laboratory).  The New York Times piece had a really strange coda:

Dr. de Cabo, who says he is overweight, advised people that if they want to try a reduced-calorie diet, they should consult a doctor first. If they can handle such a diet, he said, he believes they would be healthier, but, he said, he does not know if they would live longer.

Some scientists still have faith in the low-calorie diets. Richard Weindruch, a director of the Wisconsin study, said he was “a hopeless caloric-restriction romantic,” but added that he was not very good at restricting his own calories. He said he might start trying harder, though: “I’m only 62. It isn’t too late.”

Then there is Mark Mattson, chief of the laboratory of neurosciences at the National Institute on Aging, who was not part of the monkey study. He believes there is merit to caloric restriction. It can help the brain, he said, as well as make people healthier and probably make them live longer.

Dr. Mattson, who is 5-foot-9 and weighs 130 pounds, skips breakfast and lunch on weekdays and skips breakfast on weekends.


A circumcision compromise?

By Razib Khan | August 26, 2012 10:17 pm

The New York Times has a piece on an update to the American Academy of Pediatrics position statement on circumcision (shifting toward a more pro-circumcision position of neutrality). In the United States the rates of circumcision for infant boys has gone from 80-90% to ~50% (there are regional variations, so only a minority of boys in the Pacific Northwest are circumcised). A few years ago Jesse Bering put up a post, Is male circumcision a humanitarian act?, where he actually wrote “Nobody knows where your child will live as an adult (perhaps Africa), or how rampant HIV will be there….” I like taking probabilities into account, but this is ridiculous.

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Why some people don't think Down Syndrome is bad

By Razib Khan | July 13, 2012 7:16 pm

I often criticize Lefty readers for their lack of reality-basis. Specifically, they often want to align reality with their own normative preferences, even though normative preferences aren’t necessarily contingent upon reality (e.g., sex differences). My post on Down Syndrome has elicited similar responses, but from people one might term social conservatives. So, for example, Ursula and Matthew Hennessey have taken to denouncing me on Twitter, albeit for statements that they no doubt find extremely objectionable. Not too surprising. But I found this post, A gift named Magdalena, particularly instructive:

But we aren’t victims. In fact, we’re the opposite. We are supremely lucky. Magdalena isn’t sick. Down syndrome is not a disease; it’s merely a collection of traits, all of which occur, though not all at once, in so-called “normal” people.

But how could Down syndrome be a gift? Surely that’s taking it too far. How could a lifetime of likely dependency be a gift? How could impaired cognitive development be a gift? How could gastroesophageal reflux disease and its expensive, twice daily medicine be a gift? How could two full years of potty training with no end in sight be a gift?

The truth is that there is no objective bright line between trait and disease. In fact, nature does not know trait or disease, it only knows phenotypes. Being white skinned in a pre-modern world is a disease at the equator, and being black skinned in Scandinavia would also have been a disease. In theory you could argue that Down Syndrome is not a disease either. The Hennessey’s are correct that the collection of traits of DS individuals can be found elsewhere. So imagine that a chemical exposure or some such thing functionally transformed a child with a normal karyotype into one with Down Syndrome. How would most people feel about this? Would parents view it as a gift?

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MORE ABOUT: Down Syndrome, Theodicy

Who is the decider of the good life?

By Razib Khan | March 18, 2012 2:21 pm

‘Ashley treatment’ on the rise amid concerns from disability rights groups:

A controversial procedure to limit the growth of severely disabled children to keep them forever small – which ignited a fiery debate about the limits of medical intervention when it was first revealed five years ago – has begun to spread among families in America, Europe and beyond.

Five years ago details first emerged of Ashley, a nine-year-old girl living near Seattle. She was born with developmental disabilities that meant she was unable to talk or walk, and continues to have the cognitive ability of an infant.

The core of the treatment was hormone therapy: high estrogen doses to bring forward the closure of the growth plates in her bones, which would in turn stop her growing. In addition, surgical interventions included removal of her nascent breast buds to avoid the discomfort of fully-formed breasts later in life, and a hysterectomy to avoid menstruation.


Silvia Yee, a lawyer with the Disability Rights Education & Defense Fund that is run jointly by disabled people themselves and parents of children with disabilities, said: “This is what we were fearing. It is becoming just one more choice on the menu of possibilities – a medical operation that will change a person’s life. Who has the right to decide to change an individual into a different entity?

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American medicine & American red-tape

By Razib Khan | February 13, 2012 6:08 pm

I just attended a presentation where a researcher outlined how epigenomics could help patients with various grave illnesses. Normally I don’t focus on human medical genetics too much because it always depresses me. I don’t understand how medical geneticists don’t start wondering what hidden disease everyone around them has. In any case the researcher outlined how epigenomic information allowed for better treatment, so as to extend the lives of patients. All well and good. But then one individual in the audience began asking pointed questions as to the medical ethics of the enterprise, and whether the researcher had cleared some legally sanctioned hurdles. More specifically, there was a question whether exploring someone’s epigenomic profile might expose private information of their relatives! (because relatives share epigenomic and genomic profiles to some extent)

Frankly I began to get enraged at this point. People are suffering from terminal illnesses, and considerations of the genetic privacy of their near relatives are looming large? Seriously? The reality is that manifestation of a disease itself gives one information about the risks of their relatives. In any case, the researcher admitted that further progress in this area is probably going to be due to the investments of wealthy individuals (e.g., people like Steve Jobs who have illnesses) as well as outside of the United States. You’re #1 America!

CATEGORIZED UNDER: Health, Human Genetics, Human Genomics
MORE ABOUT: Medicine

Personal genomics: more than fun & games

By Razib Khan | November 10, 2011 11:48 am

My main current interest in personal genomics right now is pure recreation. I don’t expect much utility out of it, because a lot of correlations between genes (SNPs, etc. ) and traits/diseases are rather weak. But there are some exceptions. Recently I was temporarily put on a prescription medication and I wanted to check if I was a fast or slow metabolizer. The material you see in the medical literature is that Europeans tend to be slow metabolizers, while Asians tend to be fast metabolizers. Since I’m Asian, I’m probably a fast metabolizer, right? Not so fast! Though I’m geographically Asian (my family hails from Asia), in terms of ancestry South Asians tend to be closer to Europeans, though with some affinity to East Eurasian populations as well. But another issue for me is that I clearly have 10-15% more recent East Asian ancestry, which is not typical in South Asians. In other words, I can’t infer with any confidence from generalizations about Asians and Europeans in the American medical literature to my personal status.


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CATEGORIZED UNDER: Genomics, Health, Personal Genomics
MORE ABOUT: Personal genomics

Eugenics as a luxury of the affluent

By Razib Khan | August 24, 2011 1:12 pm

In the comments below Jason says in regards to the connection between eugenics and genocide and the “slippery slope”:

In your current comfortable first world circumstances, you are right the slope is perhaps not that slippery. I hope you are never tested in a less comfortable setting as then I think you might find it can be pretty slippery after all.

A reference to the interlocutor’s status as a citizen of the comfortable First World (which itself is a somewhat archaic term by now I think) seems de rigueur in many arguments. And I think many people will find it plausible that someone in an affluent consumer society would be blind to the “dark side” of eugenics, and how it could lead to genocide. But I think this plausibility is entirely superficial, and collapses upon closer inspection. Rather, it is I believe in “First World” and advanced nations where the likelihood of the ubiquity of eugenics and possible genocide predicated on systematic eugenics is going to be the most probable outcome.

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MORE ABOUT: Eugenics, Health

None dare call it eugenics

By Razib Khan | August 18, 2011 6:59 pm

In the comments below Phillip Lemky observes:

Hi Razib. I find disturbing all this talk of assortative mating and biological castes, as it sounds eerily similar to eugenics. Please correct me if I’m mistaken to be making this connection.

This is a common response to some of the things mooted on this weblog. Freddie deBoer even sent me a peculiar email last year expressing how appalled he was at some of the topics and comments in these parts (if you know Freddie’s internet reputation, this is not surprising behavior). First, I don’t know what people mean by “eugenics.” Here is the first sentence in Wikipedia for the eugenics entry:

Eugenics is the “applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population”, usually referring to human populations….

Wikipedia isn’t authoritative, and colloquial definitions can deviate from “official” definitions. As a rule I don’t generally talk much about state coercion or manipulation of the reproduction of the citizenry, so I don’t see that I’m talking about classical eugenics. But, it does seem that there are eugenical implications in the mass action of human behavior and the flexibility of choices which modern humans have. Consider this long article in The New York Times Magazine, The Two-Minus-One Pregnancy:

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MORE ABOUT: Personal genomics

Pleasure through signalling

By Razib Khan | August 9, 2011 1:51 am

As some of you know, I have a problem. An addiction that is. For most of the year I stock up on fresh habanero pepper. Usually I try to limit myself to 1-2 peppers per meal…but when not in the company of others who may civilize me I can lose control and eat more than half a dozen in a sitting. After the first few peppers they just don’t taste as spicy, and I suppose psychologically I am under the illusion that enough peppers will bring back the pleasure high of a few moments earlier. I developed this habit not through cultural inculcation. Rather, when I went off to college and no one supervised me I began to eat more and more peppers, and developed an extremely high threshold of tolerance. By the end of college I began to raid my parents’ thai peppers at home to the point where they complained that I always left their stock depleted before going back to school. At this point I can drink tabasco sauce like gatorade.

But the different parts of the gastrointestinal system adapt differently. When I “habanero gorge” I develop extreme pain in my bowels in a few hours, and of course there are issues the next day. Over the years I’ve poked around the literature on possible correlations between pepper consumption and stomach cancer, or the anti-pathogenic properties of peppers. I’m pretty sure I’m well beyond the limit of normal consumption in any of these studies.

My primary motivation in consuming peppers is pure hedonism, as can be attested by the fact that my consumption is constrained by the presence of others. But there are clear social consequences to eating extremely spicy food. People take notice when you pile on crushed read peppers onto pizza, or pull out a habanero at In-N-Out Burger. At nice restaurants you sometimes get well known for being the guy who likes the habanero paste lathered onto his beef, to the point where new servers might drop by to gawk. There can be a clear element of social signalling in consuming very spicy foods. In short, people can think you are a “badass.” Of course actually I’m a cheerful and self-effacing individual! (granted, with a casual tendency to verbally bludgeon people)

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1 out of 3 young Iranian men "gay"?

By Razib Khan | August 3, 2011 10:46 am

Married at age 21

A few years ago the president of Iran, Mahmoud Ahmadinejad, asserted that his nation did not have gays as they did in the West. What Ahmadinejad seems to have meant is that a public gay identity does not exist in Iran. He has to be aware that homosexual behavior is not unknown in his nation. More generally Ahmadinejad’s comments brought up the issue of men having sex with men throughout the Middle East before marriage. This is a taboo topic in much of the region, so getting good quantitative data seems pretty much impossible. But today PLoS Medicine came out with a paper with a result which suggests that the anecdotes of relatively widespread homosexual behavior in the Middle East are not totally unfounded or unrepresentative (the journalist Hugh Pope has indicated that Middle Eastern men have sometimes assumed he would naturally be open to sexual propositions because he was a Westerner. He grew a mustache to discourage such inquiries) . The paper is about HIV, Are HIV Epidemics among Men Who Have Sex with Men Emerging in the Middle East and North Africa?: A Systematic Review and Data Synthesis. Here’s the figure which jumped out at me:

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CATEGORIZED UNDER: Data Analysis, Health

Probability of pregnancy by age

By Razib Khan | July 31, 2011 2:25 pm

I just finished reading My Fertility Crisis, which is excerpted from a longer piece you can get on Kindle for $1.99. The author is a single woman in her early 40s who is going through IVF treatments, without success so far. She outlines the choices she made over her life which may have influenced her current situation.

After reading the piece I came back to an issue I’ve wrestled with before: it’s often really hard to find information on probability of pregnancy online in the form of charts. The reason is that there’s so much information, and much of it is skewed toward people who are undergoing treatment for infertility. But why look when you can generate your own visualization? I  found a pregnancy probability calculator online which I cross-validated with some of the literature. Here is the best case scenario for probability of pregnancy if you are trying in the natural fashion (the probabilities exclude women who are clinically infertile, which is a rather slippery category strongly dependent on age, so the older cohorts are probably much larger overestimates than the younger ones):

The main focus is really the decade of the 30s for women. Here is a figure from Ovarian Aging: Mechanisms and Clinical Consequences which shows a finer-grain decline in fertility:

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CATEGORIZED UNDER: Culture, Data Analysis, Health
MORE ABOUT: Fertility, GSS, infertility

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This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

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