January | 2011 | Kathryn B. H. Clancy, PhD

Monday, January 31st 2011

Iron-deficiency is not something you get just for being a lady

When I was thirteen years old, I got my period. Soon after, I remember going with my mother to the nurse practitioner’s office — her name was Debbie. Debbie told me that once girls got their periods, they were more likely to be anemic, and I would have to watch out for it. She suggested I start to take an iron supplement.

Something about that conversation irked me, even when I discovered that I was slightly anemic a few years later. I disliked the implication that one could be pathological just by being female. And I didn’t understand how it was that menses, which is only about thirty milliliters of blood loss per menses, could have such a profound impact on women’s iron status.

When I was in college, I studied this in a bit more depth in my undergraduate thesis. I discovered two important studies:

First, most people assume that the sex difference in iron stores in males and females, which begins at puberty, is due to the onset of the period and looks like this:

Figure 1. Made-up data to demonstrate the assumed way the sex difference in hemoglobin is produced.

However, the sex difference in iron status in males and females derives from an increase in male iron stores at puberty, not a decrease in female iron stores. This has to do with oxygen transport and testosterone (Bergstrom et al 1995). This means that the difference that occurs at puberty actually looks like this:

Figure 2. Made-up data to demonstrate the actual way the sex difference in hemoglobin is produced.

Second, the main culprit for iron-deficiency anemia (IDA) in men is upper-gastrointestinal bleeding, so when men present with IDA the first thing they do is an endoscopy. When women present with IDA they give her iron supplements and tell her to go home because it’s just her ladybusiness. Kepczyk et al (1999) decided to actually do endoscopies on women for whom a gynecological source was diagnosed by a specialist for their IDA. They found a whopping eighty-six percent of these women had a gastrointestinal disease that was likely causing their IDA. Therefore, menses likely had nothing to do with their IDA, and the assumption that menses made them pathological actually obstructed a correct diagnosis.

The majority of the women in that study were bleeding internally, and no one had figured it out until then because they had periods.

When I went to graduate school, I wanted to study menstrual and endometrial functioning because the assumption that it inherently causes disease seems to lead to a life of frustration with the medical system for many women. I figured it would be good for us to better understand variation in this part of the body… so that’s what I did. I went to rural Poland, where my colleague Dr. Grazyna Jasienska has a lovely field site perfect for testing my questions about the endometrium: I wanted a non-industrial population, but couldn’t choose one so remote that I didn’t have access to a hospital, since the women would need to do ultrasounds for me to image their endometria. Then, I didn’t set out to test specific questions about IDA, but Dr. Jasienska wanted to do some blood tests on my subjects for a related study, and happened to do a full work-up on them.

Without meaning to, I ended up with two very useful pieces of evidence: measurements of their endometrial thickness, and their iron status. I also knew their dietary iron intake since I did 24-hour diet recalls. I realized that I had the evidence in front of me to test the relationship between menstruation and anemia directly, rather than indirectly like other studies I had read.

It was a matter of some simple correlations (Clancy et al 2006):

Figure 3. Red blood cells (RBC) and hemoglobin (Hg) are positively correlated with endometrial thickness (from Clancy et al 2006). Click to embiggen!

Take a look at the p-values for the relationship between endometrial thickness (ET) and red blood cells (RBC), and ET and hemoglobin (Hg): both are statistically significant. What’s more, the relationships are positive. That means that the thicker the endometria, the better the iron status. I’ll admit, when I ran these stats my hypothesis was simply that there would be no relationship, likely meaning that the effect of ET on iron status was at most neutral. But a positive effect? At least in this test, there is no support for the prevailing medical assumption that menses is correlated with IDA.

I was reminded of this study of mine recently, because it was cited by someone else studying something a bit different (vanity Google Scholaring will get you that). Elizabeth Miller, a graduate student (though she may have since defended) at the University of Michigan, wrote a very interesting paper on maternal hemoglobin depletion, which is the situation where pregnancy and lactation deplete iron stores. Miller (2010) studied this phenomenon in two populations in northern Kenya, a settled population and a more pastoral one, as a way to understand the differential impact of interbirth interval, energetic constraint, and dietary iron intake on maternal depletion. I’m going to focus just on the part of this study related to issues of menses and IDA.

Miller found that iron stores slowly increase in lactating mothers with months since birth, but also that the more children these women had, the lower their hemoglobin. This makes sense in terms of where iron needs to be allocated during pregnancy and lactation, and how women with many children might not have enough time or resource to replete their iron before having their next kid.

But the really cool finding, to me, was that resumption of menses after pregnancy was positively associated with hemoglobin. Resumption of periods after pregnancy is highly variable, and largely dependent on energy availability and lactation practices. These results, that iron stores increase once you start getting your period again, indicate again that menses is not having a negative effect on iron stores. So this is the second study I know of to show a positive relationship between menses and iron status.

Ladies, unless you are menorrhagic (bleeding more than 120 milliliters each cycle) your period is not doing you wrong. If you have iron-deficiency anemia and your doctor is insisting it’s because you slough off your endometrium from time to time without doing a single test to confirm it, you may want to insist on an endoscopy. It could save your life.

References

Bergström E, Hernell O, Persson LA, & Vessby B (1995). Serum lipid values in adolescents are related to family history, infant feeding, and physical growth. Atherosclerosis, 117 (1), 1-13 PMID: 8546746

Clancy, K., Nenko, I., & Jasienska, G. (2006). Menstruation does not cause anemia: Endometrial thickness correlates positively with erythrocyte count and hemoglobin concentration in premenopausal women American Journal of Human Biology, 18 (5), 710-713 DOI: 10.1002/ajhb.20538

Kepczyk, M. (1999). A prospective, multidisciplinary evaluation of premenopausal women with iron-deficiency anemia The American Journal of Gastroenterology, 94 (1), 109-115 DOI: 10.1016/S0002-9270(98)00661-3

Miller EM (2010). Maternal hemoglobin depletion in a settled northern Kenyan pastoral population. American journal of human biology : the official journal of the Human Biology Council, 22 (6), 768-74 PMID: 20721981

47 Comments →

Friday, January 28th 2011

Science Online 2011: Underrepresentation hurts us all

In my second year of graduate school, I was in a study group with a few other grad students: in particular I remember a white female student and an Asian-American female student. Somehow we got on the topic of admissions, where we all admitted, jokingly, to feeling like impostors. Then the white female student stated that she didn’t believe in affirmative action, and expressed her view with quite a bit of anger. “Besides,” she finished, “I just don’t see race.”

I was completely paralyzed, and felt like I had no way to articulate what was wrong with what she just said. She happened to leave the room shortly after her statement. I turned to my Asian-American friend.

“Doesn’t see race?” She almost shouted. Tears sprang to her eyes. “When she says that, she doesn’t see ME.” I looked at her, mute, wanting to cry myself for the shame of not knowing how to be a better friend.

* * *

I haven’t always been the best ally. At times, I probably haven’t been an ally at all. The story I related above was the only one I dared share where I could sufficiently pseudonymize the characters. It was not the first, nor was it the last, time I was struck dumb by racism.

I did learn to speak up and interrupt racism, and slowly have figured out ways to make the elimination of racism and sexism priorities in my life. But I have a long way to go.

The MLK, Jr Memorial panel at Science Online 2011, like the women scienceblogging panel, was up against some stiff competition: Defending Science Online, Standing out: Marketing yourself in science, Blogging networks and the emerging science communications ecosystem and Not All Marketing is Evil: Getting Life Science Companies to Support Science Online. I’ll admit to sitting near the back with the thought I might divide my time between this session and one other. Yet within the first few minutes I sat there, I knew I was in the right place. David Kroll, who you know all over the internet because of his great blogs Terra Sigillata and Take as Directed, opened by playing the guitar and singing Bob Marley. Within a few bars, about a third of the audience was singing along with him. I was too busy trying not to cry to join in.

I was emotional for a number of reasons… because of the wonderful contradiction of David sitting up there and singing, because of the warmth of the room, where it felt like we had a shared mission. David contradicted the paralysis a lot of allies face, because we are so afraid of doing it wrong, of making the mistake that exposes the racism and privilege we are working so hard to cover up.

In addition to discussing Martin Luther King, Jr’s history in Durham and the surrounding area, David shared with us the following quote from Irving Epstein (which it turns out David wrote about a year ago here):

In 2005, more than two-thirds of the American scientific workforce was composed of white males. But by 2050, white males will make up less than one-fourth of the population. If the pipeline fails to produce qualified nonwhite scientists, we will, in effect, be competing against the rest of the world with one hand tied behind our backs.

Danielle Lee of Urban Science Adventures, and Alberto Roca of Minority Postdoc, were also panelists. Danielle was engaging and smart: she talked about issues of underrepresentation in science, as well as access and trust of science in minority communities. Alberto, who I had also heard speak as an audience member at a few other panels, also talked about underrepresentation issues in science, the invisibility and isolation of being a person of color in science, and how to operate against that isolation. Here are a few of their broader points (any butchered or incomplete thoughts are my fault only):

People of color and from underrepresented groups often have to pass in order to survive in science.
People have to be mentored all the way up the chain: several stories were mentioned where women and people of color were not adequately prepared or professionalized for their jobs and suffered for it.
Impostor syndrome is universal.
You act like a role model when you have a voice, so if you aren’t speaking up you aren’t a role model. Also, if you are invisible or are ignored/underappreciated, you will have a harder time being an effective role model. So the knife cuts both ways.
As Danielle says, science needs a new PR campaign. The African American community has serious trust issues with science and with good reason: this community has been exploited, undervalued, ignored.
Related to the above, there was some discussion of issues of religion and science; namely, that it is a mistake to completely discount or scoff at those with religion. Religion, faith, and religious practices have an important cultural component for many minority communities in the United States and beyond, and to write off their beliefs is to write them off as people. Even if that’s not what is intended, that is certainly what is heard.

The entire session was moving — all three panelists were so thoughtful and kind to one another, they answered audience questions so well, and the audience was committed to the issue of underrepresentation in science. I have a few last thoughts of my own that I’d like to share, as a way to extend the conversation about women scienceblogging to be more inclusive.

First, I don’t think white people or people with privilege should shy away from conversations about underrepresentation, race, or ethnicity. It is time to just be comfortable with the fact that we are going to make mistakes. If we are well-meaning and want to eliminate racism and other oppressions, then the mistakes we are going to make will not be as bad as the worst ones faced by those to whom we’re trying to be allies. Those of us in this community who are academics tend to encourage our students to make mistakes, because we know they will learn from them. But the stakes feel so high in this situation that we are paralyzed. Guess what? Being paralyzed is actually worse than making a mistake. You can apologize for a mistake. There isn’t much you can do to fix things if you stay out of an important fight.

Second, you know the isolation we talk about as women scientists and science writers? Multiply that times a million and you probably have the isolation of being a person of color in the sciences. There are some different ways in which sexism and racism play out in the public sphere, at least in the US: people might be a bit more willing to make sexist comments than racist ones. However, the impact of racism is at least as harmful, probably more harmful in most ways, because it leads to social disparities in education, health, salaries, living conditions.

There are people out there who study the effects of social disparities and internalized racism on health, and folks, it’s not good. For instance, the mortality rates of blacks are significantly higher than for whites in heart disease, cancer, unintentional injury, flu and pneumonia, HIV, cirrhosis and homicide (Williams 1999). Measures of internalized racism are correlated with a higher waist circumference, abdominal obesity and insulin resistance (Tull et al 1999, Chambers et al 2004). Issues of acculturation plague immigrant women, especially second-generation women, who experience more explicit instances of racism in their lives through acculturation (Viruell-Fuentes 2007).

Finally, science will be a richer, more interesting topic when there is more diversity. And I don’t just mean it in the Small World sense: I mean that while I love the scientific method, I know the process of science to be strongly biased by who performs it, and so it is absolutely necessary that we have many different people doing and thinking about science in order to have the best possible perspective on it.

Back when I was a union organizer in grad school, my organizer and mentor told me that graduate school doesn’t weed out the weak, it weeds out the strong: it weeds out those with strong senses of self who don’t want to be exploited, who realize there are other things to do in the world and other ways to live a meaningful life. I think that is true for a lot of people who leave academia and science, and unfortunately most of the ones I know who left were women and people of color.

Here’s the problem. I want them back, I miss them: they were my dear friends. Those are the kinds of people we need to lead science, do science, communicate science, encourage and excite young people to be scientists.

Reach out for people. Be an ally. Interrupt racism and sexism. Implement changes where you work to better recruit and retain people of color. Put people of color in positions of power: they probably know how to fix this mess much better than you do. Risk making mistakes; say you’re sorry once you realize it.

But whatever you do, don’t just sit there.

References

Chambers EC, Tull ES, Fraser HS, Mutunhu NR, Sobers N, & Niles E (2004). The relationship of internalized racism to body fat distribution and insulin resistance among African adolescent youth Journal of the National Medical Association, 96 (12), 1594-8 PMID: 15622689

Tull SE, Wickramasuriya T, Taylor J, Smith-Burns V, Brown M, Champagnie G, Daye K, Donaldson K, Solomon N, Walker S, Fraser H, & Jordan OW (1999). Relationship of internalized racism to abdominal obesity and blood pressure in Afro-Caribbean women. Journal of the National Medical Association, 91 (8), 447-52 PMID: 12656433

Viruell-Fuentes EA (2007). Beyond acculturation: immigration, discrimination, and health research among Mexicans in the United States. Social science & medicine (1982), 65 (7), 1524-35 PMID: 17602812

Williams DR (1999). Race, socioeconomic status, and health. The added effects of racism and discrimination. Annals of the New York Academy of Sciences, 896, 173-88 PMID: 10681897

17 Comments →

Wednesday, January 26th 2011

The women scienceblogging revolution

At least, that’s what it feels like to me.

You’ve commented on my last post, you’ve written your own posts, you’ve tweeted and retweeted. You’ve been insightful, brilliant, and kind. You have been allies to each other. You haven’t fed the trolls.

The people of the science blogosphere are good, thoughtful people. If a real conversation about eliminating sexism was going to happen anywhere, in a way that emboldened women and made allies of men, it was going to be here. I think the combination of meeting in person, having those many women-only conversations, having such smart people in the women scienceblogging panel, and bringing the conversation back online, to where we all met in the first place, has been really good for us.

So I want to share two last things. First, I’d like to link to as many posts people have written on this topic as possible. If you don’t see your post here, link to it in the comments and I’ll put it up here. (I looked at hits in my statcounter to come up with the list, so I could have easily missed yours.)

Second, I am slowly (because it is the start of the semester and I have a million other writing projects far more important for tenure than this blog) writing a post reflecting on the MLK, Jr session I attended at Science Online 2011. I hope that as we continue talking and reflecting on issues of women in the science blogosphere, we broaden the conversation to talk about race, ethnicity, sexuality, and other related identities that are not represented or supported as strongly as they could be.

Posts related to #scio11 or the #scio11 conversation

The biology files: Women who write about science

Observations of a nerd: I’ve never been very good at hiding

The Intersection: Sex in the Blogosphere

This is Serious Monkey Business: Raison d’etre of the female undergraduate primatology blogger

Almost Diamonds: Hidden Women, Hidden Writers

The Happy Scientist: Just Ask

Fumbling Towards Tenure Track: Self-promotion tour 2011

Neuron Culture: Hey You Men Who Yell “Nice Tits”: STFU

Neuron Culture: Guest post (my original post, crossposted)

Blue Lab Coats: Linky linky… blogging and doing science while female

Neuroanthropology: Wednesday Round Up #139 (the post gets a mention here)