Why is the G-spot still such a mystery?

A couple of weeks ago I called out a woman on Dan Savage’s podcast who asserted that we know exactly what the structure of the G-spot is, that all women have it, and that every woman can ejaculate. I called her out because scientists haven’t reached a consensus on the G-spot. They’re not sure what the heck it is, how variable it is in women, or if it even exists at all.But calling her out made me wonder: Why is the G-spot still such a mystery?

To put it simply? The current research sucks.

And that’s not just my personal opinion. The Journal of Sexual Medicine did a big review of G-spot research at the end of 2010 (1). Their conclusion?

Although a huge amount of data (not always of good quality) have been accumulated in the last 60 years, we still need more research on one of the most challenging aspects of female sexuality.

For those of you who don’t speak science-ese, allow me to translate: A lot of this data is crap, and therefore we don’t know what’s going on.

After even the briefest overview of the literature, you start to understand why we’re so confused. For example, let’s look at two very popular G-spot papers from very different camps.

First, the “It’s all in your head!” camp. This is the less popular view, but there are some researchers who think the G-spot is nothing more than the placebo effect. The main study they have supporting this was done by Andrea Burri in 2010 (2). They did a twin study and claimed to find no genetic correlation for the G-spot – that is, if a woman had a G-spot, her twin was not more likely to also have a G-spot. It spread like wildfire in the media, and was even picked up by xkcd:

Except this study was a piece of crap.

For one, they did absolutely no physiological studies. How did they know if a woman had a G-spot, then? Why, they simply asked them! In the most leading, biased way possible (emphasis mine):

“Do you believe you have a so called G spot, a small areas the size of a 20p coin on the front wall of your vagina that is sensitive to deep pressure?”

If we ignore how poorly worded that question was, it still is not going to test genetic correlation of having a G-spot. Relying on personal opinion for physiological data is frankly ridiculous – would we determine how many lobes a liver has by asking people what they believe to be true? What they’re actually testing is if someone’s personal opinion about G-spots is genetic! Someone could think she doesn’t have a G-spot, but still have the exact same physiological reactions as her sister.

The other huge flaw of the study was that it didn’t take into account sexual practices. What if one twin only has sex in the missionary position, while the other is purposefully trying out stuff to reach her “so-called” G-spot? It’s wrong to assume that all types of sex produce the same time of stimulation. The researchers seemed somewhat aware of this, because they excluded bisexuals and lesbians…because they tend to have more digital sex.

Wait, what? So you have a group of people having the type of sex that, from conventional wisdom, is more likely to stimulate the “G-spot” – and you leave them out? Why not test to see if that conventional wisdom is actually right?

Well, maybe because the lead researcher is “anxious to remove feelings of “inadequacy or underachievement” that might affect women who fear they lacked a G-spot.” That’s certainly a noble cause, since women shouldn’t feel inadequate if they lack a G-spot…but it also certainly biases your research if you’re searching for a particular answer to support your world-view. Not to mention just swaps the stigma onto women who are told they’re being delusional based on crappy data.

I’ve been harping on the G-spot deniers, but the research on the other side is just as bad. I looked up the paper by Florian Wimpissinger that’s often cited as showing that female ejaculation is way more similar to semen than urine (3).

Yes, I had a good giggle that his name was Wimpissinger.

Anyway, this study looks very impressive on the surface. They did ultrasounds that found prostate-like structures in women! And urethroscopy that found a duct-like thingy! And biochemical analysis that showed it wasn’t urine! Doesn’t that sound fancy and
scientific?

Except they did a crappy job at those things.

Their ultrasound was so blurry and inconclusive that the article is immediately followed by a letter from concerned researchers saying “Dude, you totally misread that ultrasound. That’s a smudge, not prostate tissue.” And their response is basically “No, we’re right!” Not the best sign.

Maybe a prostate-like thingy.

But you know what’s a bigger problem then their possibly blurry ultrasound?

They had a sample size of two women who could ejaculate, and no control women.

Sample size of two.

No controls.

So while you can say some women may have a prostate-like structure (assuming their ultrasound doesn’t suck), you can’t say they all do. Because you tested two women out of 3 billion. What do the non-ejaculators look like? What do the women who think they don’t have G-spots look like? Humans are highly variable – height, skin color, breast size – the same could definitely apply to G-spots.

This is especially important in their biochemical study. They took ejaculate and urine samples from both women and compared them to the ejaculate from men using biochemical assays. They didn’t have a urine sample from men or non-ejaculating women to compare it to as a control. And for the second woman, they didn’t even do 5/9 of the tests! So basically they have a couple tests that vaguely show female ejaculate is more ejaculate-like than urine-like. I say vaguely because they didn’t do any sort of statistical analysis to see if this is significant or due to random chance – probably because they have a freaking sample size of two.

So from looking at these two important studies, it’s crystal clear why we don’t know what’s going on yet. The research just isn’t high quality.

But why haven’t scientists figured this out by now? How is it that we can track every individual cell in a developing worm, but we can’t tell if a structure is there or not in women? How is it that we know genetic variation at millions of sites in the genome across human populations, but we don’t know structural or physiological variation of an often discussed phenomena?

For one thing, the G-Spot is probably complicated. If I had to put my money on a hypothesis, I’d guess the G-spot is actually a combination of structures – maybe the Skene’s glands, the internal part of the clitoris, prostate-like tissue, or vaginal thickness. And I’d guess that it’s variable across women – either due to genetics or hormonal context during development. And when something is complicated, it’s a bit harder to figure out.

Part of the problem of getting a really good study is that sexual science is somewhat of an echo chamber. Almost all of the research is published in the Journal of Sexual Medicine, and almost all of the reviewers of papers are part of the same little group. They don’t have random molecular biologists reviewing their papers and weeping at their sample size, or screaming “Why didn’t you just do a mass spec run?!” There’s a reason why this stuff isn’t getting published in PNAS, Science, or Nature – maybe partly due to blushing editors, but mainly due to quality.

Another problem is that a good study of something complicated calls for thousands of samples – and it’s not easy to find thousands of women willing to participate in such a study. That’s not just because of puritanical views, though that’s definitely a contributing factor. Women have been historically mistreated under the guise of medicine, especially within the realm of sexual medicine. Treatments for hysteria, forced sterilization – those things may be in the past, but they still linger in people’s memories.

But even if you had the best scientists and a thousand volunteers, a lot of it boils down to the politics of science – especially the politics of the science of sex. In the US, the type of research that’s being done is the type of research that’s being funded – mostly from the government. And when you look at these studies, almost none of them are coming from the US – the two I mentioned were from the UK and Austria. Our puritanical views make it less likely that a massive G-spot study is going to be funded to put this question to rest.

I’m not trying to be overly patriotic, but the US produces some of the highest quality scientific research in the world. And when it’s too scared to finance the investigation of women’s sexuality, it’s no wonder we’re left in the dark.

Yet somehow there’s no shortage of money so men can keep having erections. Funny how that works.

So the next time someone claims to know exactly what a G-spot is – especially when they’re trying to sell you something – think of the science behind it. And remember, it’s okay for science to say “I don’t know – yet.”

1. Jannini, EA et al. (2010) Who’s Afraid of the G-spot? Journal of Sexual Medicine. 7:25-34.
2. Burri, AV et al. (2010) Genetic and Environmental Influences on self-reported G-Spots in Women: A Twin Study. Journal of Sexual Medicine. 7:1842-1852.
3. Wimpissinger, F et al. (2007) The female prostate revisited: perineal ultrasound and biochemical studies of female ejaculate. Journal of Sexual Medicine. 4:1388-1393.

Hey Dan Savage: Did you turn your skepticism off?

Everyone here probably knows that I’m a huge fan of Dan Savage – but this week’s Savage Lovecast was a massive failure.
A guest on the show was Heike Rodriguez, who “teaches Female Ejaculation in West Seattle.” Not exactly sure what that entails, but that’s not the problem. When she wasn’t spewing woo-woo unscientific bullshit, she was claiming women who can’t ejaculate have some sort of emotional issues, and maybe were even raped and don’t remember it.

One of the very first things she says about female ejaculation is “That’s actually a myth. Every woman can do it. Everybody has a G-spot. There’s no argument about that. The anatomy is there for pretty much everybody.”

Uh, false. Researchers still have no freaking clue what’s going on down there. Some think it’s the Skene’s gland. Some think it’s the urethral sponge. Some think it’s the thickness of the vaginal wall. Some think it’s the internal parts of the clitoris. If scientists in 2011 are still arguing over a bit of human anatomy, it’s not as cut and dry as you think.

There’s also the fallacy of “Well I’ve experienced it, therefore it must be there for everyone.” Let’s assume the G-spot does exist in some women, and it’s not just psychological. That doesn’t mean it has to exist in everyone. A lot of human traits are variable – height, weight, breast size. And some people completely lack certain structures – for example, people who are born without wisdom teeth.

Now, you’re not going to be missing something like a heart or a stomach, but the G-spot isn’t exactly necessary for survival. More likely it’s the evolutionary side effect of certain male structures, in which case it would be completely plausible that it’s variable in women.

But to say all women have it, and as definitively as she did? Outright lie.

To illustrate how little Heike knows about sexual physiology, Dan asks her if female ejaculate is urine, and her response is “It’s impossible to pee while you’re aroused. It’s really simple. You can’t pee.”

Again, untrue. Both men and women can pee while aroused. Men can’t pee when they’re close to ejaculating (not the same as arousal) or soon after ejaculation because the bladder neck closes so semen won’t go into the bladder. Totally not the same as “You can’t pee while aroused.”

At this point Dan was tries to call her out on the idea that all women can ejaculate…and that’s where it gets even worse. “It has a lot to do with emotions. […] It has a lot to do with connecting intimacy with sex. It has a lot to do with letting your emotions flow, with being willing to cry when you feel something intensely. And that’s not something thats really out there as part of sex. And I think that’s why a lot of women can’t do it. Because they haven’t connected their heart with their vaginas.”

Oh bugger off with the new-age hippy bullshit. You have absolutely no evidence to support anything you’re saying, and it’s insulting to say that women who can’t ejaculate are somehow just not being intimate enough.

And when Dan gently calls her out on that, saying that some women are just anorgasmic, she responds that she was anorgasmic because she was raped. And then implies that emotional or sexual trauma are the real reasons why women can’t orgasm or ejaculate.

Again, not an ounce of evidence, and perpetuating the mindset that women are somehow damaged if they don’t react in a certain way. Sorry, but saying “I don’t think women should feel bad” over and over doesn’t make them not feel bad when you say the only reason they don’t squirt is because they aren’t intimate enough or are traumatized.

Even though Dan tried to (too politely) question her claims, I wonder why he even had her on the show to begin with. I thought something smelled fishy when she said “If it’s really painful, then maybe some emotional pain needs to be released.” Yes, “energy.” It must be “released,” or something. A quick glance at her group’s website doesn’t list any sort of credentials for her. The only “credentials” she mentions on the show is being able to ejaculate (good for you) and being a partner of her “co-facilitator.” And the credentials for her “co-facilitator”? He’s a former minister with a Masters in Divinity in degree, and “facilitates” stuff like “dreamwork.”

If that doesn’t set off skeptical red flags, I don’t know what will.

So massive fail, Dan. How are you so skeptical about religion, but invited someone like this on your show? Did no one call in that week and you were desperate to fill the air time? I have a feeling there are at least a couple people in Seattle with actual credentials to back up their sexual information that you could have turned to. Hell, people who can use Google are more informed than she was.

I have a feeling you got a lot of angry calls because of her. I hope we get to hear some of them in the next podcast.

I just bought my genome!

Well, kinda sorta. 23andMe, one of the more popular personalized genomics companies, is having a DNA Day sale today. Usually the price to get your genome analyzed (more on this in a bit) is $199 for the kit and $9 a month for a year for their update service – where they’ll rerun your data when new research comes out. But today you can get the kit for free!

I’ve been wanting to do this for a long time but was prohibited by the price, but this is a deal I can’t pass up – so my kit is ordered. I’m prepared to muster up a lot of saliva and then still have some left over to drool over the data. Yep, not only do they give you general interpretations, but you can access the raw data – something a geneticist like me can actually have a lot of fun fiddling around with.

But before everyone runs off and buys their own kit…a warning. I honestly don’t think I’d recommend 23andMe (or any other type of personalized genomics) to a non-geneticist. Not yet, at least. There are a couple reasons:

1. The technology in this area is greatly improving. They just upgraded from a 550,000 single nucleotide polymorphism (SNP) chip to the 1 million SNP chip. That means they’re looking at a million sites in your genome that are known to be variable across humans. While that may seem like a lot, it’s really just the tip of the iceberg. Pretty soon you’ll be able to have your whole genome sequenced. You may want to wait to get the biggest bang for your buck.

2. Genome Wide Association Studies (GWAS) sort of suck, and that’s what a huge chunk of their data, especially the medical stuff, is based off of. GWAS look for SNPs that are associated with a trait, usually disease. The thing is, usually an association can explain a tiny percent of cases of that disease – something like 1%, or even less. And often times that SNP doesn’t always produce a certain trait – for example, having the infamous BRCA gene doesn’t mean you’ll get breast cancer for sure. And almost all studies are done with people of European ancestry, so if you’re not, your results will likely be very inaccurate. So tl;dr, it’s really wishy washy.

3. Because of that, you need to take your results with a grain of salt – which is hard for people without genetic or statistical backgrounds. And that can result in a lot of self-diagnosing that really can’t replace just going and talking to your doctor and giving them a medical history.

People ask if I’m afraid I’ll find out something I don’t want to know – but I’m the type of person who rather know. I’m going to be honest – If I’m predisposed to some horrible disease that will kill me in my 30s, I would not be sitting in a laboratory pipetting or programming. I very much have the view that I want to live life to it’s fullest, and I want to know if I have significantly less years to do so. That and I think learning more about my biology and my ancestry is worth the risk. I’m a scientist and a skeptic – what’s more interesting than the truth?

I obviously won’t share all of my data since much will be very personal, but definitely expect more blog posts about the subject in the future.

You know what else has unique human DNA like a fertilized egg?

Cancer.

Just sayin’.

Science aside of the day:
Well, and T lymphocytes. “T cells” are a type of white blood cell involved in the immune response. They’re special because they undergo something called somatic recombination.

Try to remember back to high school biology. During meiosis (the formation of gametes) there’s a step where Chromosome 1 from Mom and Chromosome 1 from dad can swap chunks of DNA – that’s recombination. It’s the reason why we have so much diversity – because you’re not just getting Grandma or Grandpa’s chromosome, you’re getting a mix of both.

Usually this only happens when making sperm or eggs, but there’s one time it occurs in non-gamete (somatic) cells – in the production of T cells. A protein called a T cell receptor recognizes antigens (foreign particles) from viruses, bacteria, parasites, and even tumor cells. But think of it – if there was just one gene coding for a T cell receptor, we’d only be able to recognize one type of antigen. That’s no good – we need to be able to recognize millions!

Thankfully evolution has the answer. The T cell receptor gene has three main segments: Variable, Diverse, and Joining. There are 65 V, 27 D, and 6 J – but the cell only needs one of each! That’s where somatic recombination comes in – it randomly deletes all but on of each segment, leaving the cell with a unique combination.

“But wait,” cry my more mathematical readers, “that only leaves 10,530 combinations! That’s not very diverse at all!” You’re right! These huge structural differences make up most of the diversity, but these genes are also hypermutable – they gain mutations WAY faster than other genes. So that contributes to the diversity even more!

So, are we ready to start calling every T cell a person because it has a unique human genome? I’m not sure if my psyche can stand all the funeral’s I’d be having every time I get sick.

The most logical abortion laws

We can add Alabama to the growing list of states heaping more and more restrictions on abortion – though their proposal is especially stringent. Three bills (introduced by a Republican, of course) are attempting to “redefine “person” as “any human being from the moment of fertilization or the functional equivalent thereof” — and require that all uses of the word “person” in the state constitution be accompanied by “all humans from the moment of fertilization.”

You know, maybe these people have a point. Maybe being ejected from a womb is an arbitrary cutoff point for where life begins. Maybe we do have to take it back to the zygote – the initial cell formed after fertilization. After all, that zygote has the potential to eventually become a human being!

Just like how every egg has the potential to become a zygote, which is why all girls now must constantly attempt to become pregnant after their first period, and any subsequent period will be tried as murder.

And how every sperm has the potential to become a zygote, which is why now all ejaculation except for procreational purposes will be tried as mass murder (though we can downgrade wet dreams to involuntary manslaughter).

And how every ovary and testis has the potential to produce gametes, which is why now any accidents that damage them will be tried as involuntary manslaughter, but voluntary sterilization will be tried as murder.

And how every stem cell has the potential to become a gonad, which is why now all stem cell research will stop immediately, even that done on lab derived adult stem cells.

And how every nutrient you eat has the potential to become a part stem cells, which is why now eating will be illegal. Look, we solved the national obesity epidemic too!

And how many inorganic molecules have the potential to become a nutrient, which is why now moving will be illegal, lest we disturb the fate of an atom to become incorporated into a particularly delicious carbohydrate (which you can’t eat, sorry).

And how stars have the potential to produce different elements, which is why… well, I’m not sure if we can do anything about supernovas, so we may have to let that slide for practical reasons.

I know pro-zygoters aren’t the best at science, so hopefully this helped them understand their logic a little better. I’m a horrible human being who cares more about adult women than cells and atoms, so I’m going to keep destroying all of these potential humans and looking at photos of supernovas with awe instead of horror.

But good luck to all the pro-zygoters out there in their lifestyle! I know I had a hard time eating less junk food, let alone giving up eating and all mobility. Be sure to let us know how that goes.

‘Tis a small world in biology

Today I was browsing through recent articles in Nature, looking for a potential genetics paper to present for my department’s Journal Club. ” “Somatic coding mutations in human induced pluripotent stem cells” catches my eye – I mean, come on, doesn’t that sound absolutely fascinating? I happen to glance at the name of the first author.

“Wait…Athurva Gore? …Who’s studying biomedical engineering? Hmmmm… Is that just a more common name than I think?”

After a couple seconds of Googling, I find a photo of him and some other scientists in their native habitat (awkwardly posed in front of expensive equipment) and confirm that yes, that is my ex-boyfriend’s friend that I spent a good part of undergrad hanging out with. Who I am now rediscovering while browsing genetics literature. Odd.

Congrats on the Nature paper, Athurva!

Well, if you even read this. I have no idea what the protocol is about reading friends’ ex-girlfriends’ blogs. Blogs before bros?

I know what I’m doing in 4.5 years

You and your committee may be the only people who read your PhD dissertation (well, if you’re lucky) – but you can still enjoy is aesthetically:From Street Anatomy:

A long-time Street Anatomy fan and soon-to-be doctor, Stephen, recently sent in this image of an anatomical heart made up entirely of the words from his dissertation. He put tons of effort into studying a particular cardiac arrhythmia, noted below the heart, and instead of hanging fancy diplomas on the wall, he chose to immortalize his time and efforts into a piece of anatomical art.

Someone please remind me of this awesome idea when I’m about to graduate.

Another quarter has started

Which means I’ll be geeking away with new classes!

Proteomics – This will be interesting, mainly because I know nothing about it. Well, I mean, I know what proteins are, but I’m not familiar studying them in a large-scale way. We’ll see how it goes.

Introduction to Statistical Genomics – Just an introductory statistics course, so it shouldn’t be too bad. I heard it’s pretty similar to what I took in undergrad, so it’ll mostly help me actually remember what I once learned.

Science Communication – I’m really excited about this class! It’s about communicating science to the general public through science journalism, blogging, and public speaking – could I have found a better class for me? I’m taking it as an elective since it’s offered through the Communication Department instead of Genome Sciences. It should be a blast, and hopefully improve my science blogging abilities!

I also have our “Journal Club” training class – basically prepares us to give a less sucky presentation to the department later in the quarter. I’m not too worried since I’m a sick, twisted person who does public speaking for fun, so it should be alright.

For the skeptical animal lovers

My friend Julie, who’s been very active in the atheist and skeptical movements, just started vet school this fall. She’s documenting her journey in the best way possible – blogging. I highly suggest you guys go check it out, as she talks about skepticism applied to animal health behavior a lot. I particular like her post on diets, and how vets benefit from skepticism:

I admit, raw was something that sucked me in hard and fast and I was teetering on the edge of true believer status for awhile. I had to reel it in, evaluate the evidence objectively and admit that if I held alternative medicine, faith- and prayer-based medicine, etc. to one standard but not raw diets, I was guilty of biased reasoning and cherry-picking. It’s not something that I tolerate in my colleagues and it’s not something I’ll allow myself to get away with, either.

Check the rest of the post out here.

And if my recommendation isn’t enough for you, Julie is fostering a cat that’s about to give birth. Dozens of kitten photos are imminent. Go, go follow her now!

Nerdy observation of the day

I can still use my iPhone’s touch screen while wearing nitrile gloves! Take that, mittens. And since I’m in the lab significantly more than I’m outside, this is a significant discovery. It’s incredibly important to be able to change songs without drastically lowering my pipetting efficiency.

What? Going outside except to get to and from lab? Crazy talk.