Oops, Guess Your Kids Are Gonna Get Fat Anyway...
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Wednesday, April 25, 2007
Or at least that's what the mainstream media is prepared to tell you.Despite numerous studies over the years that have shown that breastfeeding (especially if done exclusively for six months and along with a slow introduction of solids for a year or longer) does help reduce the obesity, it apparently only takes one flawed study for the media to decide to toss all the rest.
On the other hand, it's sure doing a good job of getting us all to talk about the story and to link to it, though I'm sure a news site would neeeeeeeeeeeeeeeeeever sensationalize anything just to get more readers...
...I digress.
Anyway, there's a story over on MSNBC about a new study that's been making the rounds among breastfeeding circles.
While breast-feeding has many benefits, it won’t prevent a child from becoming fat as an adult, says a new study that challenges dogma from U.S. health officials.
The research is the largest study to date on breast-feeding and its effect on adult obesity.
“I’m the first to say breast-feeding is good. But I don’t think it’s the solution to reducing childhood or adult obesity,” said the study’s lead author, Karin Michels of Harvard Medical School.
Now go back and read that first quoted line from the story and then consider this:
Dogma: a religious doctrine that is proclaimed as true without proof
So apparently, the author of the article feels that U.S. docs simply believe, on faith, that breastfeeding would cut obesity. Apparently the author is unaware of the vast number of studies that have shown this to be true.
Don't you love how the media uses those great words to influence your perception of the story from the start? Let's hear it for unbiased reporting!
Continuing on, these lines from the ABC News coverage really jumped out at me:
The Harvard study, published online this week in the International Journal of Obesity, involved nearly 14,500 women who were breast-fed as infants and more than 21,000 who were not.
In 1989, the women were asked their height and weight and what those measurements were when they were children and at age 18. Then every two years, through 2001, they were asked to update their weight information. The surveyed women were all between 25 and 42 at the time of the 1989 questionnaires, Michels said.
Ok wait. Right now, in the comments. Tell me your height and weight today and then tell me what it was at 5, 10 and 18.
Can you do it? Bet you can't. I sure as heck can't. All I know is that when I was a senior in high school I was 5'7", a size 14 and the 147 pounds that was printed on my driver's license was a lie. ;)
Let's continue...
In 2001, the mothers of these women were sent a questionnaire asking if their daughters had been breast-fed and for how long.
When possible, researchers checked medical records to confirm what the mothers and daughters recalled, but breast-feeding is not routinely documented. Still, the researchers believe the women's recollections of breast-feeding are reliable.
"A mother knows whether she breast-fed her child," said Michels, an associate professor of epidemiology.
Umm....ok. I didn't know that "because I said so" worked in research. I thought it only worked on children...and even then, not all the time.
It hasn't even been two years since I stopped pumping for Elnora and I continually tell people that I EPed for her for 14 months. Guess what? That's wrong. It was 13 months, almost to the day. Why do I say 14 months? I have no idea. Somewhere along the line that number popped out on accident and now it just comes out on its own and I end up having to correct myself.
That's only TWO years later.
My mother-in-law spent years telling me about her natural births and how great they were. Then, when I was pregnant with my first, we looked through her medical records. Turns out she had IV narcotics, a third degree episiotimy and a high forceps delivery.
She was as surprised as I was.
Sure...those memories...they're flawless. Oh yeah...and my mother-in-law was a nurse.
The study involved only women, but the researchers believe the results are equally true for men, Michels said.
Again with the "because I said so" logic. Does that REALLY work in academic settings?
So let's dig into the study a little bit and pull out some actual quotes. (If you are interested, you can view the entire study online.)
Breastfed infants gain weight more slowly during the first year of life than formula-fed infants, probably due to the natural limitations of available energy supply.
Don't you love that "natural limitations of available energy supply" wording? Don't you love how it makes it sound like breastfeeding is denying children that privilege of weight gain? Breastfeeding only has a certain available energy supply...it's not good enough people!!
...sorry...got a little carried away there.
Continuing on...
Breast milk is lower in protein than infant formula, which may affect growth.
Again, breast milk is lacking and formula rocks. We all know how great protein is, right? And your breast milk...it doesn't have as much as formula! FOR SHAME! Your children will grow into girly men and frail women that can't stand up to the rigors of life in our society.
NHS II participants were also asked to recall their body shape at ages 5 and 10 using a nine-level figure drawing
Umm. Ok. Want to see the drawings they got to choose from?
As we know, ALL women have perfect self-images that accurately reflect how they really look. I'm sure that asking women to pick themselves off of a drawing chart both now and at prior points in their life is going to provide accurate data.
Now, let's consider a few things about this study.
First, there have been numerous studies in the past that have shown that breastfeeding DOES lower the rates of obesity in children and some have even shown lower risks further down the road. That said, we shouldn't be surprised to see one come out that shows something different. Even without getting suspicious of motivations and data, consider this from Wikipedia's entry on the "misuse of statistics."
In marketing terms all a company has to do to promote a neutral (useless) product is to find or conduct, for example, 20 studies with a confidence level of 95%. Even if the product is really useless, on average one of the 20 studies will show a positive effect purely by chance (this is what a 95% level of confidence means) The company will ignore the 19 inconclusive results and promote endlessly the one study that says the product/idea is good.
Now, let's consider that one of the qualities of a good study is a study population that matches the general population. This study was made up of...nurses.
JUST nurses. Mostly white nurses (96% to be exact) at that.
Anyone else out there think that Caucasian nurses and their lifestyles and their choices are a perfect representation of the general populace?
Didn't think so.
That tells me that the only thing this study MIGHT be good for is predicting the impact of breastfeeding on obesity for nurses.
Oh yeah, it was just female nurses too...no men allowed ladies.
Add in the fact that this study is based on self-reported data, much of which relied on memory from decades prior makes me suspicious to begin with. Now, I'm not a stats person, but I think we have a few readers that are. Anyone care to weigh in on the problems with both self-reported and retrospective studies? From my understandings, the quality of data in these studies is highly suspect, but I'd love to hear some input from someone that actually knows something about statistics.
Finally, anyone wanna do some digging to see where the funding for this study came from? Because I find it very interesting that on the heels of an announcement about how researchers are developing a new type of baby formula that will "lower risks of obesity" we suddenly get wind of "the largest study EVER" and how it shows that breastfeeding does NOT lower the risks of obesity.
I'm sure those two things aren't in ANY way connected....
So basically what we've got here is a retrospective self-reported study of female nurses and their own mother's memories.
Yeah...that's the type of data that makes a compelling argument for tossing out all prior peer-reviewed research.
By the way, I've taken up real estate. Anyone want to buy a bridge?
Labels: Stats and Studies
Sounds like the "researchers" for this article need to be bombarded with calls and emails regarding their flawed logic. Remember how quickly Consumer Reports withdrew their carseat ratings when their methods were questioned?
I don't think I'd go after the researchers since
1.) I don't think they care what we think
2.) We don't fund their research, so we can't pressure them to change it
3.) I don't think they care what we think ;)
However, I think that some well written letters to the editor of all the news outlets that are carrying this story would be an EXCELLENT way to respond.
Sure it's true that breastfeeding alone will not prevent obesity. I'm sure there are obese adults who were breastfed. But I don't think that it's accurate to link only those two things - breastfeeding and adult obesity. I could breastfeed my child until they are 7, and then feed them crap for the rest of their lives, while they sit around playing video games.
Anyway, I continue to be amazed at how scientist feel the need to pick apart and examine the rightness or wrongness of breastfeeding/breastmilk. Why aren't they doing this with other mammals? Why are we the only MAMMALS whose milk is found to be inferior?
"Why are we the only MAMMALS whose milk is found to be inferior?"
Umm...because Kangaroos, lions and cats don't have wallets?
:)
In, the baby book that my mother kept for me, she worte that I had juice at 1 month, and cereal starting at 3 months. But she insists it's not true - that I was only breastfed for several months. However I have the documentation that she kept, and I believe her records are probably more accurate than her memory. Interesting!
I am a physicist, so the statistics I use are a little more clear-cut. I emailed you an old article from The Economist about flawed statistics in medical research. I am not sure, though, if it requires a subscription, so I will include the link here, but feel free to pull the comment if it is not a usable link.
http://www.economist.com/science/displaystory.cfm?story_id=E1_RSPPSVQ
And this is just about how perfectly good numbers can be wrongly interpreted.
But from what you describe, the numbers themselves sound totally bogus.
I don't see why you are up in arms over this study. In a quick google I didn't find anything substantial supporting that breastfeeding combats obesity.
The best I found is on babycenter.com
http://www.babycenter.com/refcap/baby/babybreastfeed/8910.html
and it just says that breastfeeding may protect against obesity later in life.
I don't find it hard to believe that breastfeeding in the first year or two (or more) would radically override any other factors.
Jennifer,
I have to say, I LOVE your writing! This had me laughing until I nearly peed my pants, simply because of the way you wrote it.
I had wondered about why so many mammals in the world were obese...now I know the answer.
Tam
I just found your blog yesterday. You so rock. I love your disection of this article. I could not have put it better myself!
i went and checked out the paper and did a little digging...
it looks like these authors have been putting out numerous studies
based on the same group of nurses. alot of their research has to do with cancer which would be in keeping with their funding from the american cancer institute. they also have some BF favorable studies, such as breastfeeding helps lower Type II diabetes in mom.
the acknowledgements lists pretty benign funding, but you would probably need to ask directly if there was any other funding sources.
i don't really have a problem with the conclusion of the study itself... breastfeeding does not prevent obesity in adolescence or adulthood and "it is unlikely to play an important role in controlling the obesity epidemic." this seems obvious since as amy said "I could breastfeed my child until they are 7, and then feed them crap for the rest of their lives, while they sit around playing video games."
I agree with writing letters. Yeah sure people's memories are reliable..yeah right. I can bearly remember what I had for breakfast yesterday. Sounds like they are talking out of their....you know whats. I also saw the Today show is bringing up breastfeeding tomorrow.
Hello, some random comments here:
Again with the "because I said so" logic. Does that REALLY work in academic settings? Unfortunately yes. That's why Ohio State ads tout their research showing that global warming is true, and that even attempting to think about criticizing evolutionary theory is protested to the nth degree.
Umm...because Kangaroos, lions and cats don't have wallets?
I just got a really cute vision of Marty carrying a wallet on his back.
I'm no stat expert, but I do have a math degree and have taken 2 stats classes and have had to deal with it in other classes. The sampling method is key to the validity of the research, and real research doesn't assume things to be true for segments of the population not included in the sample (like men). Any studies that rely on personal recollection is going to be unreliable. I could have bought it if they checked these women's old medical records from when they were kids or something, but not, "Uhh I was 4'3'' and weighed 57lbs in Kindergarten. I have no idea what my weight or height was before 2nd grade and only spotty memories before high school.
You could check the growth chart in my mom's kitchen though if you wanted to be scientific about it.
Also, my parent's dogs were breastfed and they always end up huge. Explain that!!
I think women in the US who breastfeed are probably more concerned with healthy eating habits and nutrition than the general population and that explains the link between breastfeeding and decreased obesity. As was stated above, you can breastfeed and then eat poorly and you will still get fat. Maybe there is a small direct link that makes it easier to lose weight or maintain normal weight, but it is not strong enough to overcome poor food choices and low activity levels.
That said, formula to decrease obesity risk just a horrible, ridiculous marketing claim. People need to focus on healthy food choices and active lifestyle throughout their lives to decrease their obesity risk.
Yikes! I suppose my reaction was a bit different. It seems very likely that obesity later in life is likely more a product of lifestyle choices developed over one's life than feeding choices made during just the first year or two of life. Doesn't much shock me. A grown woman who was breastfed for two years who at age thirty does not exercise, eats over 2500 calories a day is going to be get fat.
The research methodologies do not concern me either. Many of these methodologies (surveys, self-reported recollections, personal health assessments) are pretty much the same tools used in studies that have demonstrated many of breastfeeding's positive health impacts.
No harm no foul here.
Does breastfeeding magically prevent obesity? No, of course not. Most of the research I've read on it says that it's not something special in the mother's milk, as much as learning from birth to stop eating when you are full. Breasts don't come with ounce markings on them! But I know many a mom who formula fed who would insist that their baby drank every last ounce of each bottle (probably because it cost so much, lol, or because someone had given them a magic number of ounces that their baby was supposed to consume each day). Overeating causes obesity, and breastfeeding on demand helps foster that natural signal in our brains to only eat until we're full.
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