"Dr. H. Robert Superko, who directed the research at
the Stanford Lipid Research Clinic, said he doubted that the process of taking
out caffeine changes the coffee so that it raises cholesterol. Instead, he
said, the difference may result from the kinds of beans that go into various
types of coffee.In general, he said, mild arabica beans are used to make
regular coffee, while most decaffeinated brands use more strongly flavored
robusta beans."
AP via New
York Times
Published: November 15, 1989
Middle-aged coffee drinkers who
switched to decaffeinated coffee increased their blood levels of a form of
cholesterol that contributes to heart attacks, a study has found.
Dr. H. Robert Superko, who directed
the research at the Stanford Lipid Research Clinic, said he doubted that the
process of taking out caffeine changes the coffee so that it raises
cholesterol. Instead, he said, the difference may result from the kinds of
beans that go into various types of coffee.
In general, he said, mild arabica
beans are used to make regular coffee, while most decaffeinated brands use more
strongly flavored robusta beans.
Researchers have long suspected but
never proved that caffeine, the chemical that gives coffee its jolt, is somehow
involved in heart disease. But the researchers found that people who went from
regular coffee to decaffeinated coffee increased their levels of low-density
lipoprotein, the so-called bad cholesterol, an average of 7 percent.
''It's not like going out and eating
cheesecake, but the overall impact could be great,'' considering the popularity
of decaffeinated coffee, said Dr. Superko, who presented the findings on Monday
at the annual scientific meeting of the American Heart Association.
Dr.
Superko calculated that the average 7 percent increase in bad cholesterol in
his subjects could translate into about a 12 percent jump in the risk of heart
disease. 'Causes Cholesterol Changes'
''Does
coffee cause heart disease?'' he asked. ''I don't know. We can only say that
coffee causes cholesterol changes.''
The
researchers said their study was not enough to prove that decaffeinated coffee
was harmful. ''I'm not saying everyone should stop drinking decaf,'' Dr.
Superko said, ''but if people are worried, they might experiment on themselves
by having their cholesterol levels checked.''
He
cautioned that the study does not entirely exonerate ordinary coffee, because
it could contribute to heart disease in other ways, such as by triggering
rhythm abnormalities or spasms in heart arteries.
Officials
of the National Coffee Association said they were interested in Dr. Superko's
findings but were unwilling to comment in detail without seeing the full report.
George
Boecklin, president of the New York-based association, said: ''Coffee and
cholesterol have been investigated in many studies with conflicting results. We
agree with researchers that it is too soon to make any definite choices.''
The
Stanford study used 188 healthy, middle-age coffee drinkers. At the start, the
volunteers drank three to six cups a day of ordinary brewed coffee for two
months.
One
of Three Groups
Then
their cholesterol levels were checked, and they were randomly assigned to one
of three groups - more regular coffee, brewed decaffeinated or no coffee.
Cholesterol
levels remained steady in those who stayed on caffeinated coffee or gave up
coffee entirely. But bad cholesterol levels rose nine milligrams per deciliter,
or 7 percent, in the decaf drinkers.
---
RELATED
Researchers discover how coffee raises cholesterol
June 13, 2007
HOUSTON -- (June 13, 2007) -- Drinking your
coffee black or decaffeinated to keep cholesterol in check? Think again.
Cafestol, a compound found in coffee,
elevates cholesterol by hijacking a receptor in an intestinal pathway critical
to its regulation, said researchers from Baylor College of Medicine in a report
that appears in the July issue of the journal Molecular Endocrinology.
In fact, cafestol is the most potent dietary
cholesterol-elevating agent known, said Dr. David Moore, professor of molecular
and cellular biology at BCM, and Dr. Marie-Louise Ricketts, a postdoctoral
student and first author of the report. Cafetiere, or French press coffee,
boiled Scandinavian brew and espresso contain the highest levels of the
compound, which is removed by paper filters used in most other brewing
processes. Removing caffeine does not remove cafestol, however.
Studies by a co-author – Dr. Martijn B. Katan
of Vriye Univeriteit Amsterdam, Institute for Health Sciences, The Netherlands
– indicate that consuming five cups of French press coffee per day (10 to 13
milligrams of cafestol) for four weeks raises cholesterol in the blood 6 to 8
percent.
However, while the cholesterol increase
associated with cafestol had been identified previously, mainly through the
work of Katan and his colleagues, the mechanism by which it acted remained a
mystery. It was a mystery that Moore and Ricketts decided to address in the
laboratory.
For a long time, Ricketts said she was
stymied because of paradoxical effects of cafestol in the liver. However, the
discovery of a gene called fibroblast growth factor 15 or FGF 15 opened the
door to understanding how cafestol affects farsenoid X receptor or FXR in the
intestine. FXR was first identified as a bile acid receptor in studies in
several laboratories, including Moore’s.
“It
is part of the body’s own way of regulating levels of cholesterol,” said
Ricketts.
Through research in the test tube and in
mice, she and Moore found that in the intestine, cafestol activates FXR and
induces FGF15, which reduces the effects of three liver genes that regulate
cholesterol levels. While it is still unclear whether cafestol itself reaches
the liver, the finding does confirm that the effect of the compound is in the
intestine, which is directly involved in the transport of bile acids.
Moore’s interest in cafestol began several
years ago when his wife read an article on coffee’s effect on cholesterol. She
suggested that he might change his brewing method, which involved a permanent
coffee filter. The paper filters, the article suggested, removed the coffee
oils, which contain cafestol.
Moore researched the problem, and found papers
by co-author Katan. He was already working on FXR, and began to think about
whether cafestol might be affecting that signal in the cholesterol pathway.
Others who took part in the work include:
Mark V. Boekschoten, Guido J.E.J. Hooiveld and Michael Müller of Wageningen
University, Division of Human Nutrition, The Netherlands; Arja J. Kreeft,
Corina J.A. Moen, Rune R. Frants of Center for Human and Clinical Genetics,
LUMC, Leiden, The Netherlands; Soemini Kasanmoentalib of the Department of
Medical Statistics, LUMC, Leiden, The Netherlands; Sabine M. Post and Hans MG
Princen of TNO Pharma in Leiden, The Netherlands; J. Gordon Porter of Incyte
Corporation, Palo Alto, CA.; and Marten H. Hofker of the Department of
Pathology and Laboratory Medicine, University Medical Center in Groningen, The
Netherlands.
Funding for this study came from the U.S.
Department of Agriculture, National Institutes of Health, Wageningen Centre for
Food Sciences, the Dutch Organization for Scientific Research and the
Netherlands Heart Foundation.
---
Dipali
Pathak 713-798-4710 pathak@bcm.edu
---
Ed's Note: Coffee in Retrospect is a reprint column prepared by Coffee Monitor and Poor Farmer blog to provide context for the current global coffee trade by republishing news articles from the past. In this column, we intend to reprint archived prints by converting images into electronic file formats with careful conformity to originals and, whenever applicable and possible, we provide links to the sources of the information. Meanwhile, responsibility for the contents lies solely with the authors and the views expressed in the articles do not necessarily reflect our opinions.
Ed's Note: Coffee in Retrospect is a reprint column prepared by Coffee Monitor and Poor Farmer blog to provide context for the current global coffee trade by republishing news articles from the past. In this column, we intend to reprint archived prints by converting images into electronic file formats with careful conformity to originals and, whenever applicable and possible, we provide links to the sources of the information. Meanwhile, responsibility for the contents lies solely with the authors and the views expressed in the articles do not necessarily reflect our opinions.
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