How much of the digestive enzyme LACTASE does raw, unpateurized cow milk contain?
I find lots of information about the enzyme lactase being made in the
human digestive tract, and I find statements saying that
pasteurization of cow's milk destroys naturally occurring lactase in
cow's milk. But I also find statements saying that raw cow's milk does
not contain the enzyme lactase! I am trying to find out how much
lactase enzyme is in  raw, unpasteurized milk (if indeed any).
I have spend much time searching on Google for this answer and I have struck out.
Please help!

Hi mranderson,

Here you go - according to The American Council on Science and Health,
lactase does not occur naturally in milk.

The American Council on Science and Health: Health Facts and Fears:
Milk: The More Things Change, the More Technophobia Stays the Same:
By Ruth Kava, Ph.D., R.D. 
November 25, 2002
"For example, some raw milk proponents say that since lactase (the
enzyme that breaks down the milk sugar called lactose) is inactivated
by heating, pasteurization contributes to lactose intolerance because
heating would inactivate the enzyme. This statement is not true for a
couple of reasons.

First, lactase is produced (in humans and other animals) by cells
lining the small intestine ? it is not present in milk! The only dairy
product in which one could reasonably expect to find lactase is
yogurt. And even in that case, the bacteria that actually produce the
lactase are added to milk after pasteurization, so they're not heated
to high temperatures.

Second, even if there were lactase in milk, it wouldn't do us much
good. That's because this enzyme works best in the small intestine,
where it is formed. The highly acidic environment of the stomach would
inactivate it. So even if we drank milk with active lactase in it,
it's unlikely that much if any of it would survive the stomach acid
and arrive in the small intestine in an active state."
http://www.acsh.org/factsfears/newsID.81/news_detail.asp

About ACSH:
"The American Council on Science and Health (ACSH) is a consumer
education consortium concerned with issues related to food, nutrition,
chemicals, pharmaceuticals, lifestyle, the environment and health.
ACSH is an independent, nonprofit, tax-exempt organization.

The nucleus of ACSH is a board of 350 physicians, scientists and
policy advisors - experts in a wide variety of fields-who review the
Council's reports and participate in ACSH seminars, press conferences,
media communications and other educational activities."
http://www.acsh.org/about/

I was happy to find this for you from an unbiased source. If you have
any questions, please post a clarification request before
closing/rating my answer.

Thank you,
hummer

Google Search Terms Used

lactase "unpasteurized milk"

Thanks for finding this information. I appreciate your efforts.

If - as you quoted - lactase is rendered ineffective in the stomach,
why is it that lactase is added to milk to help lactose intolerant
people digest it?  This argument is completely flawed.  From
"www.lactose.co.uk" -

-High potency lactase enzyme 
-A stable and biologically active source of this plant enzyme 
-Lactase hydrolyses the lactose in milk and milk products into glucose
and galactose, two forms of simple sugars that can be digested and
tolerated by lactose intolerant individuals
-Hypo allergenic 

Recommended Intake
Add four drops of Liquid Lactase to one pint (568ml) of milk and
refrigerate for 24 hours. Use as ordinary milk.

So how would this product work if the statement regarding 'lactase
rendered ineffective by stomach asic'?  Clearly the above source is a
farce.

Hi stewped,

Thank you for your comment. In researching this question, I did my
best to find an unbiased source, in other words, a website that didn't
stand to gain by the opinions offered. The website you quoted sells
lactase, the website I quoted "is an independent, nonprofit,
tax-exempt organization".

Regards,
hummer