Hi Jean-Louis,

>
> > > The effect is a longer retaining in the stomach, and
> > > enhanced digestion (since enzymes have more time to act).
> >
> > You call a longer retention in the stomach "enhanced digestion"??
>
> Perhaps milk in liquid state would go through the digestive tract too
> quickly, and come out at the other end partially undigested.
>
Not quite...it contains protein and is thus clumped in the stomach
due to the action of hydrochloric acid. The "digestion" of milk thus
takes much too long with little or no nutritional rewards.

> > > But even in
> > > the absence of rennin, casein can still be digested by other
> > > proteolytic enzymes (pepsin and trypsin). I am not saying that
> > > digestion is 100% efficient, but that rennin is not absolutely
> > > necessary.
> >
> > Rennin is necessary in order to get at the calcium which is
> > bonded to the casein...nothing more and nothing less apart
> > from the coagulation.
>
>  - Are you sure *all* of the calcium is bonded to casein?

Yes.

>  - Are you sure digestion of casein by other enzymes (e.g. trypsin)
> does not release *any* calcium?

Yes. Rennin (or chymosin as it is also known) breaks down casein to
paracasein, which then recombines with the calcium to form calcium
paracaseinate (which separates out). In other words, the same procedure
as is used to make cheese is also used by the body (of babies) to get
at the calcium.

>  - Anyway, even if you think that rennin is necessary to use the
> calcium from milk, calcium should be more available in other forms of
> dairy (e.g. cheese).
>
Yes and no. Cheese is a two-edged sword. On the one hand it makes
the calcium available and on the other, it contains much less
phosphorus than the original milk. In other words, the ratios are
upset and the consumption of cheese thus has to rob the body of
phosphorus.

> > > In the article I cited, it was said that 25% of the calcium
> > > in milk is absorbed (figure obtained by radioisotope labeling), so
> > > calcium in milk is indeed bioavailable (but milk might increase bone
> > > loss for other reasons).
> > >
Bone loss is not caused by a lack of calcium intake (quite the opposite
as calcium tablets cause bone loss) but by the intake of bone minerals
in the wrong ratios and hence Peter robbing the bones of the missing
minerals in order to pay Paul (i.e. Paul being the proper equilibrium).

> > Even if this were true, it would merely demonstrate that milk is
> > a relatively poor source of calcium.
>
> 25% of a high amount can't be considered as "poor" (like if you earn
> $1,000,000 each month and pay 75% taxes, yon can't say you are "poor"!).
>
Don't dwell on the quoted 25% unless you know who paid for such
research results. Dwell on the fact that the U.S.A., with the highest
per capita milk consumption, also has the highest per capita incidence
of osteoporosis.

> > and if you take (your previous
> > figures) the ratio of phosphorus to calcium then it is more than
> > apparent that milk MUST rob the bones of calcium in order to
> > balance out the imbalance.
>
> My figure was Ca/P = 1.2; I thought that ratios above 1 were OK.
>
The ratio may be measurable but is irrelevant if you (all people other
than babies not weaned off) are not able to utilize the calcium in
milk.

> > 1. Why is that osteoporosis is practically unknown in rural China even
> > though they drink practically no milk at all?
>
> Perhaps because
>  -people spend more time outdoors (thus get more exercise and sunshine)

An important factor but irrelevant if milk is such a good source.

>  -they get calcium from tofu

Not to my knowledge..and soy beans are not all that healthy either.

>  -life expectancy is much lower than in industrialized countries.

Rubbish...until infant deaths are removed from the calculation.
>
> > 5. Why do some believe that those who seem to get less or no
> > uncomfortable symptoms (subjective) do not suffer from lactose
> > intolerance, i.e. even though the production of the enzyme lactase
> > also ceases or is severely cut back after weaning off?
>
> Most lactose intolerants still produce enough lactase to digest a
> glass of milk. Those who can't can still eat pre-digested forms of
> dairy (e.g. cheese, yoghurt).

I would accept the yoghurt as long as it came from cows not treated
with antibiotics, etc. and which are grazed on clean land.

> > 7. How does weaning off take place and how come infants suddenly no
> > longer want or need their mother's milk?
>
> Women in primitive tribes have children every 3-5 years. If 7 year-old
> children still wanted or needed their mother's milk, she would have
> two (or more) children to breastfeed at the same time.

Theoretically yes...but in actual fact they get stomach upsets..and
the children who are later fed cows milk not only get stomach upsets
but also earaches due to the overproduction of mucus and hence
blockages and the resulting excessive bacteria in the sinuses.

> > 8. Why do we do not feel an instinctive urge to suck the teats of animals
> > which produce milk..and would this not have been both a dangerous and
> > practically impossible task for early man?
>
> I agree that (cow's) milk is not a natural food for humans, but for
> some people, the benefits can outweigh the inconvenients (e.g. people
> on SAD(L) who don't have other good sources of calcium).

Milk never was a good source of calcium (except for babies..who would
do better with human milk and the accompanying antibodies against
HUMAN diseases which it contains).

Best regards,

Alan