Sunday, July 05, 2009

Dairy Producer Underwrites Study: Finds Vegan Diets May Harm Bones

I'm not writing this as a defense of veganism as much as I am to point out what appears to be the undermining of research by business interests. (See my post, Corrupted Research.)

The following two studies were conducted by the same authors. They were published within 3 months of each other, but have different conclusions.

Veganism, Bone Mineral Density, And Body Composition: A Study In Buddhist Nuns, Osteoporosis International, April, 2009
Ho-Pham LT, Nguyen PL, Le TT, Doan TA, Tran NT, Le TA, Nguyen TV

Effect Of Vegetarian Diets On Bone Mineral Density: A Bayesian Meta-Analysis, American Journal of Clinical Nutrition, July, 2009
Lan T Ho-Pham, Nguyen D Nguyen and Tuan V Nguyen
________

The first study, published in April of this year, compared the bone mineral density (BMD) of:
  • 105 monastery-dwelling Buddhist nuns, vegans for ~33 years
  • 105 monastery-dwelling women, omnivores
Findings:
  • There was no significant difference between vegans and omnivores in BMD
  • There was no significant difference between vegans and omnivores in lean body mass or fat mass
  • There was no significant difference between vegans and omnivores in prevalence of osteoporosis
  • Intake of dietary calcium was lower in vegans compared to omnivores (330 mg/day vs. 682) however, there was no significant correlation between dietary calcium and BMD.
Conclusion:
"Although vegans have much lower intakes of dietary calcium and protein than omnivores, veganism does not have adverse effect on bone mineral density and does not alter body composition."
________

The second study, published in July of this year, was not an original investigation, but a meta-analysis (a review of previously-conducted studies). It included 9 observational studies that addressed the association between vegetarianism and BMD.

Findings:
  • Vegetarians' bones were ~5% less dense than meat-eaters.
  • Vegans' bones were ~6% less dense than meat-eaters.
Conclusion:
"The results suggest that vegetarian diets, particularly vegan diets, are associated with lower BMD, but the magnitude of the association is clinically insignificant. ... [Such that] the effect size is unlikely to result in a clinically important increase in fracture risk."
________

Why, after conducting and publishing a more in-depth study on veganism and bone density, including a literature review, and discovering that life-long vegans have bones essentially identical in density to meat-eaters, did these researchers hastily assemble and publish a review (a meta-analysis, a type of study prone to bias since you can cherry pick which studies to include and which statistics to run) that, lo-and-behold, found a slight decrease in BMD in vegetarians?

And why did this second study, with less clinically significant results, get more attention in the media?

I don't know. But the second study was funded by Amber Alliance of Malaysia, which owns F&B Nutrition Sdn Bhd, "a dairy products producer and wholesaler." (See Update below.)

Update, July 8: It has been brought to my attention (thank you, Mr. Nguyen) that the grant provided this study from "the AMBeR alliance" may refer to the Australian Medical Bioinformatics Resource. However, the Australian Medical Bioinformatics Resource does not on their website refer to themselves as the "AMBeR alliance."

The Australian Medical Bioinformatics Resource is affiliated with the Garvan Institute of Medical Research, which is funded by "CRC for Innovative Dairy Products."
________

13 comments:

Jim, Guacamole Diet said...

QUESTION:
"Why, after conducting and publishing a more in-depth study on veganism and bone density, including a literature review, and discovering that life-long vegans have bones essentially identical in density to meat-eaters, did these researchers hastily assemble and publish a review (a meta-analysis, a type of study prone to bias since you can cherry pick which studies to include and which statistics to run) that, lo-and-behold, found a slight decrease in BMD in vegetarians?"

ANSWER:
"... what appears to be the undermining of research by business interests."

I think you got it right.

Dr. Mel said...

Great post!

esmaa said...

There are many things people say for complicated reasons that are not fact. There are many things we believe to be true that are not fact. I say eat as well as you can, keep your range of motion through vigorous exercise and die happy.

For the record: I am a 50-year-old omnivore who eats about an 89% organic, and 65% vegetarian diet and who can hike 20 miles in a day wearing a heavy pack, and whose vital signs are textbook.

I do have weak bones, but then I also had rickets and malnutrition as a child.

And I never ever, ever take any kind of payment in order to form an opinion.

I'm just sayin...

DINH NGUYEN said...

Hi Guys
You should think twice before you publicly speak
I am one of the authors, I am sponsored by AMBeR - The Australian Medical Bioinformatics Resourse, not related anything to so call AMBeR Alliance of Malaysia
http://www.amber.org.au/fellows.html
So you owe me apology since you defame me
Regards
Nguyen Dinh Nguyen

DINH NGUYEN said...

Hi
One more thing
Could you pls read more carefully, the author is sponsored by but not the study was funded by ...

Cheers
N

Jim, Guacamole Diet said...

Hmmm ... It does appear that there indeed are two very different Amber groups. The confusion seems understandable, and it looks like Doctor McDougall's site may have started or spread the error, if there was one.

DINH NGUYEN said...
This comment has been removed by the author.
DINH NGUYEN said...

Hi Jim,
Certainly, it is!
One more thing, wonder they people can differentiate between statistically significance and clinically significant, I doubt about that!
We argued for vegetarians then we are attacked. Very weird!!!
Cheers
Nguyen

esmaa said...

Begging your pardon N, but my comment was a response to my growing sense that Bix likes to give the pot a stir every now and again. When I referenced the study on my own blog (doubting that you saw that but just in case http://esmaa.wordpress.com/2009/07/03/the-secret-to-eating-well-balance/ ) I did use the phrase "Researchers claim that a vegan diet reduces one’s bone density...." My use of the word claim is in reference to the fact that what we know today we very often know better of tomorrow, science being dynamic. In no way did I aim to disrespect you or your work.

DINH NGUYEN said...

Hi Esmaa,
Take it easy,pls read my comments once more time to make sure what I mean
Cheers N

Bix said...

Hi Mr. Nguyen,

Thank you for your important work.

The study says "NDN was supported by a grant from the AMBeR alliance."

I don't know if "the AMBeR alliance" noted in the study is the Australian Medical Bioinformatics Resource or not. The Australian Medical Bioinformatics Resource does not on their website refer to themselves as the "AMBeR alliance."

However, if "the AMBeR alliance" is the Australian Medical Bioinformatics Resource, as you say, it is affiliated with the Garvan Institute of Medical Research:

http://www.amber.org.au/network.html

The Garvan Institute is funded by "CRC for Innovative Dairy Products:"

http://www.garvan.org.au/about-us/funding-bodies

DINH NGUYEN said...

Hi Bix
Just waist my time to argue with you
N

Wilma said...

This is interesting. VADLO comes to mind, it is a biomedical powerpoints search engine. There are good cartoons also.