Animal protein and osteoporosis myth

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This is a compilation of my past discussions (2007). Since this issue comes back so often, I decided to re-post it here, as the reference [or just to annoy] 8-:) . 

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Myth 1: "Populations which consume a very high amount of dairy get more hip fractures than those which don't."

and

Myth 2: "It isn't only the calcium that comes in which is important but the calcium which is leached out due to high animal protein diets.

I am sorry to disappoint the true believers, but it is just the opposite! People who avoid animal protein believing that they are saving their bones are in fact increasing the risk of osteoporosis.

The following study found that women who consumed the most animal protein (+43%) had only one-fifth risk of hip fractures:

"Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women"
by Ronald G Munger, James R Cerhan, and Brian C-H Chiu Am J Clin Nutr 1999;69:147-52.

Results: Forty-four cases of incident hip fractures were included in the analyses of 104 338 person-years (the number of subjects studied times the number of years of follow-up) of follow-up data. The risk of hip fracture was not related to intake of calcium or vitamin D, but was negatively associated with total protein intake. Animal rather than vegetable sources of protein appeared to account for this association. In a multivariate model with inclusion of age, body size, parity, smoking, alcohol intake, estrogen use, and physical activity, the relative risks of hip fracture decreased across increasing quartiles of intake of animal protein as follows: 1.00 (reference), 0.59 (95% CI: 0.26, 1.34), 0.63 (0.28, 1.42), and 0.31 (0.10, 0.93); P for trend = 0.037.

Conclusion: Intake of dietary protein, especially from animal sources, may be associated with a reduced incidence of hip fractures in postmenopausal women.

Table 4 of the study shows some really interesting data on the risk of hip fractures (from 6-th column). Namely, in addition to much lower (factor of 0.31) risk for the 43% higher consumption of animal protein, they found 1.9 times HIGHER risk associated with the 31% higher consumption of VEGETABLE protein!

Carbohydrate consumption turned out to have been a much bigger factor, perhaps the biggest factor:

23% higher consumption of carbohydrates was associated with 3 times higher rate of fractures!

If we recalculate (normalize) those risk factors per 100% (i.e. per doubling) increase of the consumption of each: total protein, animal protein, veg protein and carbohydrates, then we obtain the following:

Hip fracture risk correlation:

• Total protein: - risk reduction 3.6 times
• Animal protein:- risk reduction 4.5 times
• Vegetable protein:- risk INCREASE 2.9 times
• Carbohydrate:- risk INCREASE 4.9 times

In addition, women who experienced hip fractures (as opposed to those who didn't) consumed less animal fat, less saturated fat, less alcohol, had lower body mass index, had fewer pregnancies, smoked less, consumed more calcium, more vegetable fat and more vit D.

Heretic

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REFERENCES

Papers:

"Controlled High Meat Diets Do Not Affect Calcium Retention or Indices of Bone Status in Healthy Postmenopausal Women"

"Protein intake: effects on bone mineral density and the rate of bone loss in elderly women"

"Effect of Dietary Protein on Bone Loss in Elderly Men and Women: The Framingham Osteoporosis Study"

"Factors associated with calcium absorption efficiency in pre- and perimenopausal women"

Quote: "Women in the lowest tertile of the ratio of dietary fat to fiber had 19% lower fractional calcium absorption values than did women in the highest tertile of ratio of dietary fat to fiber"

Articles:

"Protein Saves Bone in Elders"

"New Data on Dietary Protein and Bone"

------ More references, update 1-Aug-2001 ---------------------------------------

This is based on the most recent blog article by Denise Minger quoting various peer-reviewed publications using China Study data. This is a MUST READ!

Some of the papers were co-authored by the well known expert vegan scientist Dr. T.Colin Campbell but unlike in his popular book, those papers are based on individual rather than county-averaged data. They also state completely opposite conclusion regarding heart disease, cancer and bone health which is quite remarkable for a senior mainstream academic scientist! The same man but two opposite views! Now to the subject of osteoporosis, bone density, calcium and diet:


* Dietary calcium and bone density among middle-aged and elderly women in China" by Ji-Fan Hu, Xi-He Zhao, Jian-Bin Jia, Banoo Parpia, and T. Colin Campbell.

Quote:

However, decline in bone mass after menopause for women in county WA (higher dairy calcium) was at a somewhat slower rate than for women in the nonpastoral areas (without dairy calcium).
...

Thus. differences in the rate of bone loss between these areas may be related to differences in dairy calcium intake, given that 34.6% ofealcium in county WA and none in the other nonpastoral areas was from milk. Indeed, dairy calcium was found to be more significantly correlated with bone mass than was nondairy calcium (Table 7), even though these analyses only included women with dairy food intake in counties YA and WA (n= 253). Nondairy calcium. in contrast, showed no association with bone variables after age and/or body weight were adjusted for (Table 7).

BMC and BMD at the distal and midradius were positively associated with consumption of milk (r = 0. 1 5-0.26, P [less than] 0.003) and with consumption of hard cheese and other dairy foods (r = 0.22-0.29, P [less than] 0.01) (data not shown). These results agree with those reported in other cross-sectional studies (35, 37). A similar association between daily milk intake and bone density was also reported by Yano et al (10) in Hawaiian Japanese males and females and by Shiehita (23) in 85 healthy Japanese males and females, whose calcium intakes were as low as in our study. Increasing calcium intake with calcium-rich foods (milk and cheese) was found to reduce bone loss in adolescent (34), osteoporotic (38), premenopausal (14), and lactating (39) women.

* Veganism and osteoporosis: A review of the current literature. "The findings gathered consistently support the hypothesis that vegans do have lower bone mineral density than their non-vegan counterparts."

* A Comparison of Bone Mass Measurements of Vegetarians and Omnivores. "In this review of 9 cross-sectional and 1 longitudinal study, little statistical significance between bone density and bone content was found between vegetarians and omnivores."

* Effect of vegetarian diets on bone mineral density: a Bayesian meta-analysis. "The results suggest that vegetarian diets, particularly vegan diets, are associated with lower BMD, but the magnitude of the association is clinically insignificant."

* Long-Term Vegetarian Diet and Bone Mineral Density in Postmenopausal Taiwanese Women. "Long-term practitioners of vegan vegetarian were found to be at a higher risk of exceeding lumbar spine fracture threshold … and of being classified as having osteopenia of the femoral neck."

The rest of Denise article quotes more papers co-authored by T.C.Campbell, that conclude a positive protective role of dairy, meat and fish rich diets against cancer, heart disease and other disease in China. Read it all!

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Vegans, dietary fat and Alzheimer's

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I like browsing through some vegan discussion groups looking at the papers, publications and studies they use to support their belief system. McDougall's forum is particularly useful because of their tenacity in trying to use science to justify themselves. Experience taught me that such studies are always ambivalent and very often prove a completely opposite views to those of the vegan believers who posted them.

The following study from 2003, did not disappoint me:

Dietary fats and the risk of incident Alzheimer disease.

The abstract looked very foreboding, for example, quote:

Persons in the upper fifth of saturated-fat intake had 2.2 times the risk of incident Alzheimer disease compared with persons in the lowest fifth

Not all is lost fortunately, because of the widely known practice in the medical "science" to print only the politically correct (i.e. false) information in the abstracts while hiding the true albeit inconvenient facts in the full text.

The facts are that the saturated fat data and most of the other results are generally not statistically significant!

The facts are that even when one takes the trend line across saturated fat quintiles and makes it appear statistically more significant than an individual datum (the so-called "p value for the trend") - the resulting p is still much greater than 0.05 and thus is still not statistically significant! Best illustration is the following (upper) portion of the Table 3:

The facts are that if you take the most basic age-adjusted only data (look at the first row called "Age-adjusted+"), there is no clear trend at all since the middle and the second highest saturated fat columns (quintiles) have exactly the same Alzheimer's risk as the lowest reference quintile of saturated fat!  The second and the third row (headed by "Multivariable" and "Multivariable... other fats") above are the more processed data, that seem to exhibit a weak rising trend, albeit also not statistically significant!  One shall always keep in mind that multivariable-corrected trends are dependent upon some specific model-dependent assumptions that may or may not be correct.

It gets more intereseting as one reads down the table. If one takes the above discussed saturated results on faith, beliving that the weak statistics may be reflecting some real underlying trend rather than being some artefacts of the data gathering and processing methodology (as I suspect is the case), then one should also take a notice and state that the rest of the data "proves" (also not statistically significanly) that the total fat consumption, dietary cholesterol intake, animal fat consumption and vegetable fat consumption all seem either not to correlate or to correlate NEGATIVELY (protectively) with the Alzheimer's risk! See the lower portion of the Table 3:

For example, the total fat consumption seems to be protective against Alzheimer's! The second lowest and the middle quintile in consumption of animal produce (indicated by dietary cholesterol!) also have higher Alzheimer's risk than the two highest quintiles! Animal fat consumption seems to show no correlation to Alzheimer - the trend curve is pretty flat except the third row ("Multivariable adjusted for vegetable fats and trans-fats") which shows a weak NEGATIVE (i.e. protective) trend!

Last but not least the bottom group Vegetable fats shows the strongest correlation in the whole study. That correlation is strongly NEGATIVE (protective), that is the more vegatable fat the less Alzheimer's cases! In fact that result, after "Multivariable adjusted for vegetable fats and trans-fats" - is the only one, alongside the omega-6 fat result ( which is basically its subset) that does exhibit a statistically significant trend!

Unfortunately for those who believe in the low fat dogma, this is not a good news! Especially when compared with other sources, see for example this and that.
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Do statins or low fat diets cause osteoporosis?

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New study: "Association Between Myocardial Infarction and Fractures: An Emerging Phenomenon."

Most interesting is this, quote:

...substantial temporal variations were noted (
1979 to 1989: hazard ratio, 0.81 ...
1990 to 1999: hazard ratio, 1.47 ...
2000 to 2006: hazard ratio, 1.73 ...
...
Trends were similar regardless of age, sex or fracture site. Conversely, the overall hazard ratio for death in MI cases versus controls did not change materially...

The only obvious factor that was different in the first decade (blue - less osteoporosis following a MI event) as opposed to the second and third decade of the study (red - more osteoporosis!) is the common usage of statin drugs! Perhaps a popularity of the low fat high carbohydrate diets in treating MI patients (the so-called AHA diet) may be another factor distinguishing the red from the blue decades.

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Update 16-July-2011

Another recent study found on Dr.McDougall forum, linking bone underdevelopment with malnutrition, in this case a lack of dairy products:

Thin Bones Seen In Boys with Autism and Autism Spectrum Disorder

Quotes:

The boys in the study who were on a casein-free [READ DAIRY-FREE (added by H.)] diet had the thinnest bones. In fact, the 9 boys who were on a casein-free diet had bones that were 20 percent thinner than normal for children their age. Boys who were not on a casein-free diet showed a 10 percent decrease in bone thickness when compared to boys with normal bone development.

The study authors wrote that bone development of children on casein-free diets should be monitored very carefully. They noted that studies of casein-free diets had not proven the diets to be effective in treating the symptoms of autism or ASD.

As a side note from my own experience. It reminds me that a nurse examining children at my school in the Eastern Europe, 1960-ties (I was around 12) told us that many, about a half had unusually thin but long bones in their hands and different elbow joints, as compared with the medical reference books that she used. Those children had normal food intake, were rather well fed. I always wondered what was causing the difference and that the same factor affecting bone development may have also affected the risk of autism! What was that factor? We didn't eat breakfast cereals nor drank pop. We ate a high carb medium fat diet not much different from that of the 1930-ties or before. Definitely more sugar - sugar became very cheap in the 1960-ties, and margarine became the new "health" "food" of the day plus vegetable oils became a popular cooking fat substitute in the 1970-ties. Sugar was very expensive before WWII in Poland due to special sugar tax, then became completely unavailable during German occupation 1939-1945 and then became cheap afterwards. What else other than sugar could have done the damage?

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The end of an era

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Drawn by Cecilia Bleszynski

The following Washington Post article "Final NASA shuttle mission clouded by rancor" should have had a different headline. Imagine this:

SIMIAN-SAPIENS ELITES ARE DESTROYING THE HOMO-SAPIENS CIVILIZATION!
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Vitamin K2 Reduces Heart Disease by 57 Percent

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Interesting links, some new some old. Enjoy!

From Natural Health Digest and News

Quote:

Researchers concluded that vitamin K1 had little effect on cardiovacular health, but vitamin K2 dramatically reduced it.
How do you get vitamin K2 into your diet? Vitamin K2 is found largely in meats and eggs.

Also cheese, organ meat, natto. See also my old posts on vitamin K2 related topics

Other interesting links gathered from a vegan forum (thank you Dr. Mc Dougall):


Sci Am: "Carbs against Cardio..." (refresher of an older post)

"Saturated Fat and Cholesterol Do Not Cause Coronary Heart Disease" by Dr. Paul J. Rosch

Quote:

4. No association between cholesterol levels and the severity or extent of atherosclerosis has ever been found in postmortem studies of the general population. No clinical or imaging study has found any relation between the degree of cholesterol lowering and improvement.

In one angiography study, in which blood cholesterol had been reduced by more than 25% in 24 patients, atherosclerosis was increased in 18 and unchanged in eight. Cholesterol rose in 12 other patients but only 4 showed an increase in atherosclerosis. A Mayo Clinic study similarly found that in all patients whose cholesterols had decreased by more than 60, there was a significant increase in coronary atherosclerosis.
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6. The huge and lengthy MRFIT study (Multiple Risk Factor Intervention Trial) was designed to prove the links between diet, cholesterol, and other Framingham risk factors with heart disease. Cholesterol consumption was cut by 42 percent, and saturated fat consumption by 28 percent and on long-term follow-up, those adhering to this dietary fat restriction had slightly lower coronary heart disease death rates.

However, this benefit was far outweighed by significantly increased total mortality rates, especially from hemorrhagic stroke, cancer, suicide, accidents and violence. The risk of dying from a cerebral hemorrhage was 500% greater in those with low cholesterol compared to those with high levels. In most other studies, the incidence of stroke was higher in those who ate less saturated fat.