Razib Khan One-stop-shopping for all of my content

October 25, 2012

Putting a stop on the biological clock

Filed under: Fertility,Health — Razib Khan @ 1:41 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.

September 29, 2012

The moral measure of bad teeth

Filed under: Health,Heritability — Razib Khan @ 8:57 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. ...

August 30, 2012

Being fat is like being gay (?)

Filed under: Health — Razib Khan @ 11:21 pm

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 ...

August 29, 2012

The eternal question of calorie restriction

Filed under: calorie restriction,Diet,Health — Razib Khan @ 8:22 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, ...

August 26, 2012

A circumcision compromise?

Filed under: Circumcision,Health,public health — Razib Khan @ 9:17 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.

Let’s ignore Jewish ritual circumcision, which has to be done in early infancy from what I know. The vast majority of the world’s circumcised men live in Africa and the Muslim world, with a substantial minority in the USA and American-influenced cultures.* So you don’t need to focus on infant circumcision at all. In Turkey circumcision is performed on boys who are considerably older. I understand that an 11 year old boy is not an adult, but if sexually transmitted diseases are your primary concern, then why not ...

A circumcision compromise?

Filed under: Circumcision,Health,public health — Razib Khan @ 9:17 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.

Let’s ignore Jewish ritual circumcision, which has to be done in early infancy from what I know. The vast majority of the world’s circumcised men live in Africa and the Muslim world, with a substantial minority in the USA and American-influenced cultures.* So you don’t need to focus on infant circumcision at all. In Turkey circumcision is performed on boys who are considerably older. I understand that an 11 year old boy is not an adult, but if sexually transmitted diseases are your primary concern, then why not ...

July 13, 2012

Why some people don’t think Down Syndrome is bad

Filed under: Down Syndrome,Health,Theodicy — Razib Khan @ 6:16 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 ...

March 18, 2012

Who is the decider of the good life?

Filed under: Culture,Health — Razib Khan @ 1:21 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?


There are two dimensions of evaluation here. The positive, and the normative. As alluded to above the menu of possibilities are going to expand radically in the foreseeable future. So there’s no point in putting our heads in the sand on this. You start out with preimplanation genetic screening, and move all the way to irreversible physical changes as outlined in the story at the link. In the specific case the rationale for these changes is pretty straightforward; humans with the minds of infants or toddlers but the bodies of adults can be extremely difficult to control. I have a little personal experience in this area, as I worked with a mentally handicapped young man as his “minder” for a term in secondary school. His cognitive profile was probably similar in many ways to a one to two year old, but he was of average height and somewhat above average weight. One of the major issues with this young man is that he needed to be kept under surveillance, as he had a tendency throw fits and assault random people. Conventional moral reasoning simply did not work with him, because as I said he was barely a toddler mentally (he has a very minimal comprehension of language). Now expand this to the problem which parents and relatives have in caring for an individual with the physical capacities of an adult, but the mental aptitudes of a very young child. Imagine the temper tantrums of a two year old in the body of a thirty year old. This is a reality for many.

But let’s move to the normative dimension: who makes these decisions, and who decides who and what an individual becomes? The former is to a great extent a prosaic matter of power politics. Parents and institutions, civil and governmental, have long battled over children. But the latter is a deeper philosophical issue. What makes you you? There are many individuals for whom their religious identity is simply an essential part of who they are, but usually that identity is conferred upon them by their parents. Do the parents have the right to create such an individual, with a particular sense of self? My point is that when you moot the issue of identity in a deep fundamental manner you open up a huge can of worms, and broader issues which go back to David Hume and further deep into the mists of antiquity.

Finally, as a new parent these sorts of stories have a heightened salience for me. They are usually presented in a narrative style which strips away the substance of lived experience, and pits several actors and agents against each other. Here you have the parents and a group of activists, along with the governments and hospitals. But the organic reality of living decades as a caregiver for a profoundly disabled individual is removed from the picture. The impact that it might have on other children, or on your social relations more generally are not present in the narrative. We live in a world where many parents neglect their children, or enter into the stage of life of being a parent with relative casual interest or focus. But these particular parents, who are put in a position of extreme difficult emotionally and materially, are monitored with great care, and have a whole cadre of public interest lawyers devoted to making sure they do the right thing (the “right thing” being what others determine).

The root problem we have as a society about discussing these issues is that we don’t have a fully fleshed out explicit model for what the good life is. There are some activists in the disability rights movement who deny that the lives of people we generally classify as disabled lacking in anything. This is a complex question, because to some extent we are all imperfect. But is a world without children in wheelchairs or children with Down syndrome a lesser world? Too often the arguments in favor of allowing for nature to take its course in these matters are reminiscent to me of the arguments of Leibniz. I lean against the idea that we need the physical and mentally disabled, at least more than the suffering which these disabilities impose upon individuals who are the subjects of the suffering, or the families around them. I do not believe that we must evaluate all questions as matters of individual utility, but that is certainly where we should start.

February 13, 2012

American medicine & American red-tape

Filed under: Health,Human Genetics,Human Genomics,Medicine — Razib Khan @ 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!

November 10, 2011

Personal genomics: more than fun & games

Filed under: Genomics,Health,Personal genomics — Razib Khan @ 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.

 

But that’s OK. It turns out that one locus determines most of the effect of this trait, and that locus has been genotyped in 23andMe. Using Promethease I ran my genotype, and it concluded I was a slow metabolizer. This has some utility in terms of when I take my medication. And it’s the first time that I can think of 23andMe giving me “actionable” information.

More broadly I realized that this sort of genotyping service is particularly useful for those of us who fall between the European/East Asian/African categories used in much of the American medical literature. The main concern is that genetic background might matter. That is, a SNP or set of makers correlated with a disease or trait in one population may not be correlated in another population. But this concern is less of an issue for me now after the past few years. Though some different risk alleles are being found across populations, by and large they’re pretty portable. Though the utility of this service for South Asians is obvious, in the American context it will probably be most useful to mixed-race Latinos, who are going to segregate out in traits at large effect loci between their parental populations (if those traits do differ).

August 24, 2011

Eugenics as a luxury of the affluent

Filed under: Eugenics,Futurism,Health — Razib Khan @ 12:12 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.


There is a large general issue at the root of this confusion, the implicit progressive “Whiggishness” in our sensibilities, which derives in part from the power of science to advance in ...

August 18, 2011

None dare call it eugenics

Filed under: Health,Personal genomics — Razib Khan @ 5:59 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 ...

August 9, 2011

Pleasure through signalling

Filed under: Food,Habanero,Health,Peppers,Scoville,Spice — Razib Khan @ 12:51 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 ...

August 3, 2011

1 out of 3 young Iranian men “gay”?

Filed under: Data Analysis,Gay,Health,homosexuality,Homosexuality in Iran,Iran — Razib Khan @ 9:46 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 ...

July 31, 2011

Probability of pregnancy by age

Filed under: Culture,Data Analysis,Fertility,GSS,Health,infertility — Razib Khan @ 1:25 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 ...

July 25, 2011

Dominance, the social construct that confuses

Filed under: Dominance,Genetics,Health,Medicine,Penetrance,Sickle cell — Razib Khan @ 12:31 pm

A story in The Los Angeles Times seems to point medical implications of being a sickle cell carrier, Sickle cell trait: The silent killer:

At least 17 high school and college athletes’ deaths have been tied to sickle cell trait during the past 11 years. The group includes Olivier Louis, a player at Wekiva High School near Orlando, who died on Sept. 7, 2010, following his first football practice.

You have surely heard about sickle cell anemia. It is a recessive disease which expresses in those who carry two sickle cell alleles. T-boz of TLC has the disease for example due to her homozygosity. But the allele also famously confers some resistance against malaria, which explains its concentration in regions which have historically been malarial. Sickle cell is arguable the classic case of heterozygote advantage driving the emergence of a recessive disease. The frequency of the allele is balanced at the equipoise between the proportion of people who are more susceptible to malaria if its proportion is too low and those who express sickle cell anemia if its proportion is too high. This advantage is obviously context sensitive. The ...

July 6, 2011

Marry far and breed tall strong sons

ResearchBlogging.orgThe Pith: When it comes to the final outcome of a largely biologically specified trait like human height it looks as if it isn’t just the genes your parents give you that matters. Rather, the relationship of their genes also counts. The more dissimilar they are genetically, the taller you are likely to be (all things equal).

Dienekes points me to an interesting new paper in the American Journal of Physical Anthropology, Isolation by distance between spouses and its effect on children’s growth in height. The results are rather straightforward: the greater the distance between the origin of one’s parents, the taller one is likely to be, especially in the case of males. These findings were robust even after controlling for confounds such as socioeconomic status. Their explanation? Heterosis, whether through heterozygote advantage or the masking of recessive deleterious alleles.

The paper is short and sweet, but first one has to keep in mind the long history of this sort of research in the murky domain of human quantitative genetics. This is not a straight-forward molecular genetic paper where there’s a laser-like focus on one locus, and the mechanistic issues are ...

June 23, 2011

Good calories, bad potatoes?

Filed under: Health — Razib Khan @ 1:02 am

Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men:

Within each 4-year period, participants gained an average of 3.35 lb (5th to 95th percentile, −4.1 to 12.4). On the basis of increased daily servings of individual dietary components, 4-year weight change was most strongly associated with the intake of potato chips (1.69 lb), potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed red meats (0.95 lb), and processed meats (0.93 lb) and was inversely associated with the intake of vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb), and yogurt (−0.82 lb) (P≤0.005 for each comparison). Aggregate dietary changes were associated with substantial differences in weight change (3.93 lb across quintiles of dietary change). Other lifestyle factors were also independently associated with weight change (P<0.001), including physical activity (−1.76 lb across quintiles); alcohol use (0.41 lb per drink per day), smoking (new quitters, 5.17 lb; former smokers, 0.14 lb), sleep (more weight gain with <6 or >8 hours of sleep), and television watching (0.31 lb per hour per day).

I took the results when they controlled for other variables and filtered them all so that their p-values were 0.001 or less (in fact, of ...

May 29, 2011

Less fear of the flu for asthmatics?

Filed under: Asthma,Health — Razib Khan @ 7:57 pm

One of the reasons I tend toward a bit of hypochondria is probably the fact that what for others are inconvenient minor ailments often trigger my asthma. So nice to see this, Why Does Flu Trigger Asthma?:

When children with asthma get the flu, they often land in the hospital gasping for air. Researchers at Children’s Hospital Boston have found a previously unknown biological pathway explaining why influenza induces asthma attacks. Studies in a mouse model, published online May 29 by the journal Nature Immunology, reveal that influenza activates a newly recognized group of immune cells called natural helper cells — presenting a completely new set of drug targets for asthma.

If activation of these cells, or their asthma-inducing secretions, could be blocked, asthmatic children could be more effectively protected when they get the flu and possibly other viral infections, says senior investigator Dale Umetsu, MD, PhD, of Children’s Division of Immunology.

Although most asthma is allergic in nature, attacks triggered by viral infection tend to be what put children in the hospital, reflecting the fact that this type of asthma isn’t well controlled by existing drugs.

For various reasons I’m moderately skeptical of incremental improvements in life expectancy in developed nations through ...

May 21, 2011

Kissing and cancer

Filed under: Cancer,Disease,Health — Razib Khan @ 10:39 pm

I recently listened to Paul Ewald talk about how a lot of cancer is due to infection on the radio show To the Best of Our Knowledge. That wasn’t too surprising, Ewald has been making the case for a connection between infection and lots of diseases for a while. What jumped out at me is his claim that kissing can spread some of the viruses. Here’s something he told Discover a few years back:

D: How do we get infected with these dangerous pathogens?

PE: Two of the most powerful examples are sexual transmission and kissing transmission, and by that I mean juicy kissing, not just a peck on the cheek. If you think about these modes of transmission, in which it might be a decade before a person has another partner, you realize that rapidly replicating is not very valuable—the winning strategy for the microbe would be to keep a low profile, requiring persistent infections for years. So we would expect that disproportionately, the sexually transmitted pathogens would be involved in causing cancer, or chronic diseases in general. You can test this. Just look at the pathogens that are accepted as causing cancer—Epstein-Barr virus, Kaposi’s sarcoma–associated herpesvirus, human ...

Older Posts »

Powered by WordPress