Topic: Milk = strong bones = lie?

[KC Parsons]

Correct me if I'm wrong, but doens't sodium deter calcium absorption?

[Steven Low]

Correct me if I'm wrong, but doens't sodium deter calcium absorption?

Why would it?

[KC Parsons]

I was told (and don't accept with much truth) that too much sodium pulls calcium away from the bone, so in the end it would slow down bone growth

[tombb]

Sorry for jumping in on a random topic but it caught my attention.

I think what is missing in this discussion is the concept of relevant amounts.
For example, someone can argue "something in milk (pH or whatever) doesn't let you absorb it well". That can very well be true and still be such a minor effect that it doesn't matter much in practice.
We don't really have 100% absorption for most things (often for good reasons), and even so what's so special about that? Say you absorbed 85% of the calcium in milk or cheese, does that mean it's not good for your bones? And are other sources of calcium from diet any better? I have to find the study but calcium from vegetables has a lower absorption rate than milk and in general it's harder to get it in the same amounts as easily (I think people tested this by using ratios of absorption vs isotopes with calcium from milk and from some calcium-rich vegetables for example). And even if somehow sodium or something else could in some cases pull calcium away from bones, that again might be something that (if it happens at all) only happens when you don't already have enough calcium available and the effect of consuming milk would still result in a positive increase of calcium available and used by bones.

So while the specifics about pH, pasteurization, etc might be interesting, you have to put them in perspective too in relation to how relevant they are to actual total net effects.

Some people can have intolerance for milk as someone mentioned in this thread and of course that is a very valid reason not to drink it for them. Personally I have no side effects from drinking milk or consuming any dairy products and find them to be an awesome part of my life. It's especially useful for me because I don't have many other sources of protein aside from eggs (I don't get to eat meat or fish unfortunately because I feel bad for them and prefer not to kill anything, as a personal choice).


So the answer to the OP question is milk is good for your bones, unless you are, say, lactose-intolerant etc in which case it's probably not worth it for you and you can still do fine with taking supplements or trying to get it from other sources. For some however milk is just a more convenient and delicious source (of calcium, proteins, and for me great no-fat taste) than the alternatives.

[KC Parsons]

After doing a little research, it turns out there's actually an almost-significant amount of sodium in bones as a whole. So, using critical thinking, I'd have to say that it makes no sense that sodium would go against bone growth.
But, in the world of health, it's not always as things seem.

[Jake Vigil]

Just a quick thought after reading this.

I heard it mentioned that Milk is Basic, and that Calcium requires an Acidic environment to be absorbed.
Though milk isnt really basic, it seems to me that even if it was, your STOMACH ACID would aid in the absorption of the Calcium

That would make sense to me anyways.

[tombb]

The final answer is that milk is a very good source of calcium and it's absorbed well by your body, it's been measured and compared to the absorption from many other sources in several studies.

People can come up with all sorts of theoretical reasons why it might not be absorbed, just like I could come up with all sorts of reason why you shouldn't be able to see something as far away as the sun ("stellar dusk could block our view!","light could get 'dimmer' in that huge distance", etc, all sounding semi-plausible) but obviously they are not sufficiently relevant factors because the simple fact is that you can see the sun just fine from earth, and you do get high amounts of calcium absorbed by drinking milk.
Some of the effects people mentioned might even happen, but if they each reduced your absorption by just say 2%, who cares...
In fact even if calcium absorption from milk was only 50% and from vegetables it was 30% with most vegetables containing very little calcium and milk containing a lot, the conclusion would still be the same, drinking milk is a good way to get and absorb a lot of calcium in your body.

There are often ulterior motives for at least a few of the crazier arguments on either side of a question, too.
For example there are vegetarians that would like to convince others that any non-vegetarian diet is also unnatural and nutritionally bad even when it's not true, because they wish it was the case.  That's why it's important to actually consider the relevance of each argument or evidence and see if it really matters.
I don't eat meat/fish or wear leather (just because I don't like to hurt things if I can avoid it), which I guess technically makes me a vegetarian, but I would never claim that it's a nutritional advantage to give up meat (well aside from a small risk of prions hehe). In fact if you are trying to gain muscles you'll have a difficult time trying to compensate for all the good things that come with meat (for example the naturally occurring creatine which you can't get from just plants, etc). If you have a strong reason not to use milk (allergy etc) you can compensate in other ways, but it's not really easier or better for other reasons, and if you are not allergic and find it delicious and it makes you feel great, you definitely don't have any health reason to deprive yourself of such a great food.
It's really about being realistic and not going overboard believing something just because you would like it to be true.

[Ken PKChiro]

don't make assumptions tombb .  I don't make these statements because I want them to be true.  because there is evidence always on both sides of the coin, and I happen to be toward one of them.

[Marshall Cent Lewis]

Throwing my own experience in there, it's not just about the calcium intact of milk.  All those other nutrients included in the process of taking in calcium need to be of proper amounts as well.  I used to have osteoporosis (yes, the old people disease..) even though I drank about 1/2 to 3/4 gallons of milk a day.  The reason?  Vitamin D deficiency.  I have no idea about milk itself being beneficial or not to the bones, but just getting a lot of calcium by itself is not necessarily enough.

[tombb]

I wasn't referring to anybody specifically on the forum, that's why I used the wording "some of the crazier theories on either side", and I would imagine you would not put yourself in that category

But the main point is that there are many questions that are completely answered, so there is no need for people to have different opinions or feel like evidence just makes them 'lean' one way or another.
You can just measure absorption over and over as people have done and just look at the numbers to see the high absorption of calcium from milk.
If you had any actual evidence showing low absorption of calcium that would be surprising so you would want to post it, it's always good to review and discuss things directly (especially from actual numbers and measurements) instead of just talking about them hypothetically.

Also, as Cent mentioned, there are other factors, like Vitamin D, other minerals etc, but that's another place where whole foods like milk (or a well-engineered chemical replacement like baby formula) is great.
It's food that evolved for the specific purpose of making infants of various species grow significantly (bones and all) even as their only food source. It has all those nutrients like vitamin D and calcium in good proportion.
I like skim milk the most, and Vitamin D is liposoluble, so it's normally removed from skim milk, but that's why you have Vitamin D skim milk or Vitamin pills, if you know what you are doing for food you can choose how to compensate and even make them better.
There might be other things some people might not like about milk (allergy, taste, cows), but calcium absorption and bone health really shouldn't be one of them.

[Ken PKChiro]

my issue is that the milk isn't the ideal environment for calcium absorption... You have lots of hormones, particularly growth hormone in milk, which creates yes bone building which IMO is the main cause of bone growth, not the calcium itself, as usually osteoporosis conditions are caused by vit D def.  Plus, milk tends to suck out other minerals over long periods of time... but.  small stuff.  I agree that you can get calcium from milk, but no more than calcium salts lets say.

[Chris Salvato]

Ken, I am not sure I agree with the GH comment there.

By the time GH is absorbed, I am fairly certain it has already been broken down in the stomach/duodenum by digestive enzymes into simple amino acids.

With that said, ingested GH has no more effect on growth than a big slab of meat does...because its a protein in and of itself -- not a hormone by the time it reaches the blood stream.

[tombb]

Definitely we're agreeing on the general issues, for example there are many other sources for calcium (including calcium pills) if you don't want to use milk for any reason. And definitely you don't automatically get bone growth just by having more calcium, the body generally needs to already want to build bone (for example adolescence, mechanical stimulation, growth stimulus of calories and proteins etc).

The only things that I think would need more discussion are statements like "ideal environment for absorption" (as compared to what? is another food source higher and by how much? and is it significant enough to really care? most things are not 100% absorption, even calories, but people still get fat without too much trouble hehe).
Or even statements like "suck out other minerals over long times", which again seems like something you should back up with specific measurements. If it were true generally you should be able to measure a small loss of minerals every time you consume it, which then adds up (or whatever other measurable mechanism you are suggesting).
I don't think that's ever been observed, but that would be more conclusive than, say, a longitudinal social-science study based on questionnaires, asking people how much milk they drink a year and see if they have higher incidence of mineral deficiency. Correlations can be useful hints but they are often misleading. That's because there are many other things people could be doing by association like eating more processed foods and less vegetables or exercising less that could be responsible for any of those statistics.

So if you have actual studies with measurements for those 2 points I wouldn't mind looking them over to sort them out.

[Ken PKChiro]

heya, tombb, I appreciate your informed responses , its good for me to do this as sometimes I hear these things said by practicing doctors.  And being a doctor, its good to be corrected before I start spouting stuff off to patients.  (this includes you chris)  I've been corrected in this thread, which is great and its a given that my knowledge of biochemistry is lacking in comparison with biomechanical and structural..  Here are some sources pertaining to the discussion.  Also, I don't have time to continue the discussion as fun as it is, I have a licensing examination in a few days.

From pubmed

1: Am J Clin Nutr. 2006 Aug;84(2):371-4. Links
Absorbability and utility of calcium in mineral waters.

Heaney RP.
Creighton University, Omaha, NE, USA. rheany@creighton.edu
BACKGROUND: Calcium intake in North America remains substantially below recommended amounts. Bottled waters high in calcium could help close that gap. OBJECTIVES: The objectives were to summarize and integrate published absorbability and biodynamic data concerning high-calcium mineral waters and to combine these data with hitherto unpublished analyses from my laboratory. DESIGN: The usual library database was searched. The absorbability of calcium from a high-mineral water labeled with tracer quantities of (45)Ca was measured in human volunteers as a part of an otherwise low-calcium test meal. Published reports that used differing load sizes and meal conditions were harmonized by making corrections based on published calcium absorbability data. RESULTS: All the high-calcium mineral waters had absorbabilities equal to milk calcium or slightly better. When tested, all produced biodynamic responses indicative of absorption of appreciable quantities of calcium (ie, increased urinary calcium, decreased serum parathyroid hormone, decreased bone resorption biomarkers, and protection of bone mass). CONCLUSION: High-calcium mineral waters could provide useful quantities of bioavailable calcium.

sorry, I'm corrected.  my issue has been with milk in general, and perhaps its increased further that it should have.  Milk is good for absorption of calcium.  concerning the minerals, for the life of me, I can't find the source for the mineral absorption that I had somewhere  *scratches head*.


Int J Food Sci Nutr. 2005 Feb;56(1):13-22. Links
In vitro determination of calcium bioavailability of milk, dairy products and infant formulas.

Unal G, El SN, Kiliç S.
Department of Dairy Technology, Ege University, Bornova, Izmir, Turkey. unalgulfem@yahoo.com
In this study, the aim was to determine the in vitro calcium bioavailability of different dairy products and to investigate the effect of dry matter, fat, acidity and calcium content on calcium bioavailability of the products. For this purpose, the dry matter, fat, acidity and calcium content of different kinds of milk, yogurt, cheese and infant formulas were analysed. Then, calcium bioavailability of products was determined by an in vitro method that involves simulating gastrointestinal digestion of the product with pepsin-HCl and pancreatin-biliary salts, and then measuring the fraction of element that dialyses through a membrane of a certain pore size. Each of the product groups was examined statistically and no difference was found among milk, yogurt and infant formula groups in terms of calcium bioavailability. However, there were differences among cheese kinds according to the results of the Duncan test; all cheese kinds were considerably different from each other (P < 0.05). Moreover, it was found that calcium, dry matter, fat content and acidity did not affect the calcium bioavailability (P < 0.05). According to the results of statistical analysis that was applied to all product groups, it was found that the yogurt group was different from the other products and that the acidity affected calcium bioavailability (P < 0.05).




Chris,  its mainly the rBGH that's the issue.  in addition, it goes to the argument again of macromolecules.  My information here comes from a few books and speaking with a professor of GI in Detroit.  In general, there is more and more evidence that macromolecules are directly absorbed through the intestinal walls.  Its the same with hormones...  There is no reason for the body to break down stuff, only to rebuild it if it is usable.

This stuff is about safety of use of rBGH, which is still in hot debate.

1: Int J Health Serv. 1996;26(1):173-85.Links
Unlabeled milk from cows treated with biosynthetic growth hormones: a case of regulatory abdication.

Epstein SS.
School of Public Health West, University of Illinois, Chicago 60612, USA.
Levels of insulin-like growth factor-1 (IGF-1) are substantially elevated and more bioactive in the milk of cows hyperstimulated with the biosynthetic bovine growth hormones rBGH, and are further increased by pasteurization. IGF-1 is absorbed from the gastrointestinal tract, as evidenced by marked growth-promoting effects even in short-term tests in mature rats, and absorption is likely to be still higher in infants. Converging lines of evidence incriminate IGF-1 in rBGH milk as a potential risk factor for both breast and gastrointestinal cancers.



as for the effect of feeding cows this, that there is an effect:
Increased milk levels of insulin-like growth factor 1 (IGF-1) for the identification of bovine somatotropin (bST) treated cows.

Daxenberger A, Breier BH, Sauerwein H.
Institute for Physiology, Research Centre for Milk and Food, Freising-Weihenstephan, Germany.
The present EU moratorium banning the use of bST to increase milk yield implies the need for official controls. Our study aimed to identify milk from bST treated cows via the induced increase of insulin-like growth factor 1 (IGF-1) concentrations. A non-extraction radioimmunoassay for IGF-1 was improved and thoroughly validated for milk. Accuracy was 99% recovery in a fortified sample material, the precision was 5.1% intra-assay variation and 13.4% inter-assay variation. Parallelism was proved by a dilution experiment which yielded a regression line with a slope (-0.7%) not significantly different from zero (P = 0.534). Naturally occurring milk IGF-1 levels were recorded in 5777 random milk samples from the Bavarian dairy cow population. In samples from lactation week 7 to 33, the effect of somatic cell count (SCC), protein content and parity could be quantified and corrected; thus a normal distribution (-0.068 mean +/- 0.440 s) of the corrected logarithmic IGF-1 levels (corr ln IGF-1) was obtained. IGF-1 concentrations occurring in milk from bST treated cows were recorded in 33 Brown Swiss cows treated once with rbST (POSILAC). Mean corr in IGF-1 levels increased by 0.828 and 0.477 in first parity and older cows, respectively. Thus 60% and 29%, respectively, of the positives could be detected at a 95% probability. If our results are confirmed in experiments with more bST treated cows and with prolonged treatment intervals. IGF-1 measurements might be useful to monitor for bST application in milk samples.

I wouldn't call it a stretch to say it enters the consumer.  And that the rBGH has an effect on us.

[Chris Salvato]

Noted!

Thanks for the info Ken...always appreciate being informed

[tombb]

Good luck with your exam Ken, and glad we agree on even more stuff now hehe. 
It's always nice to compare notes and sort of bump heads a little if it makes us double check things and learn or be even more informed in the process.

On a side note on the hormones and milk, I always think of IGF-1 as an awesome molecule, so while it might be a meaningful concern for others, it almost seems like a plus to me haha. 
Similarly you might not want to tell bodybuilders or they will just inject cows of the same thing they would otherwise try to inject into themselves