Hi Alan,

> > 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.

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

> > 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).
> >
> 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"!).

> 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.

> 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)
 -they get calcium from tofu
 -life expectancy is much lower than in industrialized countries.

> 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).

> 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.

> 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).


--Jean-Louis Tu <[log in to unmask]>