May 8, 2003
NUTRITION NEWS FOCUS
"Nutrition news is important.  We help you understand it!"

Today's Topic: Cholesterol -- Too Much? Too Little?

A study presented recently at an American Heart Association meeting
described results that low blood cholesterol increases the risk of one
type of stroke.  Seven hundred stroke victims were compared with 3,700
healthy people.  The two types of stroke are ischemic and hemorrhagic;
the first occurs when a blood vessel is blocked and the second when a
blood vessel breaks and bleeds into the brain.  Ischemic stroke is
about four times more common than hemorrhagic stroke in the U.S. and
Europe, but just the opposite in Japan (where cholesterol is low).
People with cholesterol over 280 were twice as likely as those at 230,
the group's average, to have an ischemic stroke. People with
cholesterol under 180 had double the risk of those at 230 for a
hemorrhagic stroke. According to the researchers, high cholesterol
probably accounts for 10 percent to 15 percent of ischemic strokes.
Low cholesterol is the cause of perhaps 7 percent of hemorrhagic
strokes.

Since 200 is now the upper limit for desirable cholesterol levels, it
is curious that the comparison value for this study is 230, which was
the average for these patients.  You have to ask if there was no
benefit of having cholesterol under 230.  The researchers indicate
that blood cholesterol levels were only responsible for 17 to 23
percent of all strokes.

HERE'S WHAT YOU NEED TO KNOW: There is no doubt that very
high serum cholesterol is dangerous for heart disease but no one
really knows what level is optimal.  The usual publicity about the
lower, the better is not based on good science.  Although the wire
services said these results were new, the question about low
cholesterol and increased cancer and strokes has been hotly debated by
scientists for more than 20 years.  Your Advisor published the first
animal studies aimed at answering the question about low blood
cholesterol and cancer in 1981, and this is still not resolved.  There
are several previous studies on low cholesterol and stroke which found
the same result as in the current study.  In fact, total mortality is
increased with very low cholesterol levels (under 170) compared with
the lowest rate found at about 210 mg cholesterol.  There is no doubt
that very high serum cholesterol is dangerous for heart disease, but
no one really knows what level is optimal.  The usual publicity about
the lower, the better is not based on good science.


(This story originally appeared in Nutrition News Focus on
February 8, 1999.)

Rob