Are Asian women immune to osteoporosis?

Factual Questions
1

This is taken directly from the Dairy Farmers of Ontario’s website. It sounds like a crock to me, but I figured someone here would know.

"Why are we told that we need milk when people in many Asian countries such as China have low rates of osteoporosis and do not drink milk on a regular basis?

The structure of the hip (primarily the femoral neck) is different in non-whites, especially in Asian women providing a resistance to hip fracture not found in people of northern European decent."

I can’t find the logic in this. First of all if it were true who’s to say that the consuming of dairy products didn’t cause the deformed femoral neck in northern Europeans? And second of all, wouldn’t the Asian people be breaking arm and leg bones left and right, literally, if the only protection was a strong femoral neck?

2

There are two separate issues here; I can discuss one of them…

A) There are skeletal differences between races. This allows MEs autopsying Jane Does to issue a finding like: “Asian woman in her mid-late 20’s with good teeth, and a well-healed wrist fracture” from skeletal remains. Some of these differences could make a person of one race more or less susceptible to hip fracture than someone of a different race, but I don’t know if this is the case for Asian women.

B) Asian women are less susceptible to osteoporosis than are Caucasian women. African-American women are even less susceptible to osteoporosis than are Asian women. By this I mean than by age 70, over 50% of Caucasian women have lost sufficient bone mass to meet the definition of osteoporosis. Approx 35-40% of Asian women have, and only ~25% of African-American women have.

Your concern about other fractures is well-taken, but in older patients hip fractures are second only to strokes in taking fully independent-living adults & making them nursing home-dependent. Other fractures do not interfere with daily living or the same degree of immobility that hip fractures do.

Sue from El Paso
Siamese Attack Puppet - Texas

Experience is what you get when you didn’t get what you wanted.

3

Rate of osteoporosis are measured by the occurance of hip fracture in post-menopause.
Some of the various explanations for the statistical differences…

“Important racial differences in both bone mass and prevalence of fractures are seen. Persons of African descent have higher bone mass and lower rates of fractures. Asian women have lower bone mass than Caucasian women, but, interestingly, the rate of hip fractures is not proportionally lower. Theories to explain this discrepancy include shorter hip-axis length in the Asian women, previous activity levels that were higher, or the cultural practice of taking care of the elderly and not allowing them to leave their beds, reducing the opportunity for falling”

From… http://uwcme.org/courses/bonephys/opop.html

4

Nice site, funnee, but a few clarifications are needed:

Osteoporosis, as stated on the cited web page, is defined by the WHO as:

Bone mass below that representing - 2.5 SD from the mean of young women.

Established osteoporosis is defined by the presence of osteoporotic fracture (hip fracture, vertebral compression fracture, or wrist fractures).

Bottom line: One need NOT have a fracture to have osteoporosis.

2nd point:
This makes no sense: “Asian women have lower bone mass than Caucasian women, but, interestingly, the rate of hip fractures is not proportionally lower.”

From the rest of the information available on the site, I suspect the quote (which was correctly taken from the source) meant to say the rate of hip fractures is not proportionally higher.

I will double other sources since this is conflict with what I remember…

Also, going to another page within the site: http://uwcme.org/courses/bonephys/predfxrisk.html

there are conflicting graphs.

One (blue/lt blue/lt green) is the graph I see on a day-to-day basis that shows the mean bone mass in 70 year olds just below the line defining osteoporosis.

Beneath it, however, is a graph (blue/teal/aqua) showing that the mean bone mass is equal to a T-score of -1.5, or in the osteopenia range. (Osteopenia = bone loss below normal, but above the level defining osteoporosis. Borderline bone mass would be a reasonable way to look at it).

I have no idea why the 2 graphs looks so different, although I suspect that the first graph shows specifically the femoral neck (where most fractures occur, while the 2nd graph is labeled as total hip)

  • Sue
5

From the site… http://www.osteovision.ch/aio/v5-n1/V5_0005-0013.html

“During the low calcium diet, urinary calcium was decreased (-82.4 mg/day), fractional calcium absorption increased (+24.0%), true calcium absorption decreased (-210.7 mg/day), rate of calcium deposition (V0+) decreased (- 128.4 mg/day), and overall bone balance decreased (-77.9 mg/day). Women from osteoporotic families differed from controls in having higher true calcium absorption during the high calcium period (382.0+/-114.4 vs 292.3+/-112.2 mg/day), in showing an increase in V0+ on increase in calcium (from 849.1+/-653.8 to 1058.3+/- 15.2 mg/day), and having a lower balance in bone calcium turnover during both low and high calcium periods (Figure 5). In comparison to granddaughters, grandmothers and mothers had a lower calcium absorptive efficiency, a lower true calcium absorption, and a lower overall balance in bone turnover. V0+ was higher in grandmothers than other generations.”

Sue does this support that a high calcium diet for osteoporotic women has better calcium absorption ? It’s hard for a layman to wade through these studies. This site seems to have the best online material on osteoporosis and related studies. http://www.osteovision.ch/aio/

6

Whew - Just a little terminology to sort through there :slight_smile:

English version:

  1. Lower calcium intake -> Less calcium excreted in the urine.
    BAD POINT: This indicates that there is an overall deficit of calcium in the blood. PTH (parathyroid hormone) is probably increased to cause such low calcium excretion, but it also accelerates calcium loss from bone.
    GOOD POINT: Low calcium excretion minimizes kidney stone risk. If you do take calcium supplements, be sure to take plenty of water!

  2. Lower Calcium intake -> Increased % of ingested calcium absorbed, but the total amount of calcium taken in in lowered.
    BAD POINT: Less Calcium absorbed, the less is available to be deposited into the bones & the more likely the body is to be pulling calcium out of the bones.
    GOOD POINT: Too much calcium left behind in the intestinal tract can definitely cause constipation; less calcium left behind causes less constipation.

  3. Lower calcium intake -> more negative bone balance = more calcium pulled out of the bones on a daily basis.
    BAD POINT: faster bone loss -> increased likelihood of osteoporosis and fracture.
    GOOD POINT: None.

Bottom line: Calcium supplements do increase the available pool of calcium, which a) can lead to increased addition of calcium to the bone, and b) decreased release of calcium from the bone, so the while the overall balance of calcium is still negative (losses exceed gains) is is much less negative than without calcium supplements.

Too much calcium though, can cause constipation & kidney stones.

  1. Young women absorb calcium more effectively than older women. Older women lose bone at a faster rate than do younger women.

I did check on the issue of Asain women & osteoporosis. They are slightly (no numbers available) MORE likely to have low bone mass, but moderately LESS likely to have fractures. So it depends whether you are asking for rankings of osteoporosis (low bone mass), or established osteoporosis (history of osteoporotic fracture).

  • Sue
7

Many thanks Sue for putting that in English for me. Now I actually understand some of it.

8

Majormd said:
>> African-American women are even less susceptible to osteoporosis

How about African-African women? Why would black women outside the USA be different from those in the USA?

9

BTW, take a look at any advertisement for one of those osteoporosis drugs. They all say that Asian women (meaning Asian-decendents now living in the countries that the magazine is distributed) are at as high a risk of osteoporosis as caucasian women. Think about it. If the genetics are the same, something must be different. Could it be the diet?

I never gave the site addy :o : http://www.milk.org/nutfaq2.htm#q34

The dieticians at that site know who butters their bread. It’s too bad that can’t do a better job of making a believable argument. They also give misinformation about food allergies on the site.

10

I heard that the French don’t get heart disease because they don’t drink milk. Is this true?

Thanks–Matt

11

someone once told me that the reason Asian women are less likely to have the osteoporosis is because of the large ammount of seaweed in our diets (culturally that is…). Can anyone tell me if there’s any truth to this - I power down the seaweed like any other good Asian - but damn; watch me have that nice little hump when I’m 80 :0

12

Asian women are not immune to osteoporosis. Go to you local Chinatown and see many old women almost bent over double from spinal fractures due to osteoporosis.