On Fri, 4 Feb 2000, Dori Zook wrote:

> I know that Cordain and others are looking long and hard at where early
> humans got thier calcium.  Anyone on the list have a study or two on this
> topic handy?  Any information on this criticism would be greatly
> appreciated.

Well, while I was looking at Seely's anti-dairy work, I found the
following abstract, which suggests that we are getting too much
calcium and might do better on a lower-calcium diet.  Since Seely
is not arguing for paleo, he makes the suggestion that the
phytate in grains is *useful* for reducing the absorption of
calcium from the milk we shouldn't be drinking.  But we can see
the more elegant solution of adopting a lower-calcium diet in the
first place.

But I haven't read the commentaries yet, which I'm sure are
sizzling.

Todd Moody

Int J Cardiol 1991 Nov;33(2):191-8

Is calcium excess in western diet a major cause of arterial disease?

Seely S

The daily requirement of a young adult for calcium is 300-400 mg,
the quantity consumed in many third-world countries. The dietary
intake can be doubled or trebled by consumption of milk, thus
half a litre of milk, consumed by many individuals daily in
prosperous countries, adds 600 mg. The need for calcium is
greatly reduced in old age, so that the excess from a given
intake becomes more pronounced. The potential hazard of a high
intake is that a small fraction finds its way into soft tissues.
The aorta is notably prone to calcification, resulting in loss of
elasticity. The aorta and its large branches constitute an
elastic reservoir, distended during systole and contracting in
diastole. This contraction provides the energy for the
maintenance of diastolic pressure, which decreases with the
deterioration of elasticity and needs a continually increasing
systolic pressure to restore its normal value. The heart is
disadvantaged in two ways. Its work is increased by having to
eject the systolic volume into a stiffer reservoir, and the
diastolic filling of the coronary arteries is reduced. This is
the main cause of hypertension in old age--there is no increase
in blood pressure with age in undeveloped countries where intake
of calcium is low. The best cure would be prevention: the
reduction of intake of calcium in prosperous countries. Failing
that, phytic acid is suggested as the best calcium antagonist.
Phytic acid, a natural product present in grains, converts
dietary calcium into insoluble phosphates which pass unabsorbed
through the digestive tract. The presently used calcium
antagonists are not so satisfactory.

Comments:
  Comment in: Int J Cardiol 1992 Feb;34(2):227-8
  Comment in: Int J Cardiol 1992 May;35(2):281-3

PMID: 1743778, UI: 92077756