http://www.healthsentinel.com/news.php?event=news_print_list_item&id=173
Judy Foreman, "Uncommon benefits in common spice?", Star Tribune,
August 29, 2004,
Link: http://www.startribune.com/stories/1556/4949168.html
A common spice enjoyed by many Americans appears to lower blood sugar
and cholesterol, a potential boon to millions of people with diabetes
and high cholesterol.
The spice is cinnamon. In the December issue of Diabetes Care,
researchers from the Beltsville Human Nutrition Research Center in
Maryland, part of the U.S. Department of Agriculture (USDA), reported
on an encouraging study of 60 people with Type 2 diabetes in Pakistan.
It showed that as little as one gram a day of cinnamon -- one-fourth
teaspoon twice a day -- can lower blood sugar by an average of 18 to
29 percent, triglycerides (fatty acids in the blood) by 23 to 30
percent, LDL ("bad"😉 cholesterol by 7 to 27 percent and total
cholesterol by 12 to 26 percent.
Although some scientists suspect that cinnamon may be toxic at very
high doses, at the small doses used in this study, the spice appears
to be safe, said Richard Anderson, the lead scientist in the
Beltsville lab and senior author of the paper.
To be sure, one study on 60 people and a few other studies on the
biochemistry of cinnamon in cells in lab dishes provide far too little
data to recommend that Americans immediately start wolfing down the
spice. On the other hand, the USDA study was impressive, said Melinda
Maryniuk, a senior dietitian at the Joslin Diabetes Center in Boston.
Cinnamon "can't harm in small doses, it may help, and it's not adding
calories," she said.
She warned, however, that people with Type 2 diabetes should monitor
their blood sugar more frequently if they take cinnamon because it
could intensify the effects of diabetes medications, including
insulin.
Alice Lichtenstein, a professor of the Friedman School of Nutrition
Science and Policy at Tufts University in Boston, added another
caveat: Don't use the news on cinnamon to indulge regularly in
cinnamon buns or muffins.
Scientists already have a pretty good, albeit incomplete, idea of how
cinnamon may work, at least in diabetes, said Don Graves, an adjunct
professor of biochemistry at the University of California, Santa
Barbara.
An active, water-soluble ingredient in cinnamon, proanthocyanidin,
part of a family of chemicals called polyphenols that are often found
in plants, somehow worms its way inside cells.
An insulin aid
Once inside, it helps to activate the part of the insulin receptor
that sticks into the cell. (The other end of the receptor sticks out
through the cell into the bloodstream to catch molecules of insulin,
which escort sugar to cells.)
Once the receptor is activated, whether by insulin or
proanthocyanidin, a cascade of chemical reactions occurs so that the
cell can use energy from sugar.
"Cinnamon makes insulin more efficient," Anderson said. In diabetes,
the problem is that insulin no longer does a good job of escorting
sugar into cells. Cinnamon "makes cells more sensitive to the insulin
that is available. And if you improve insulin sensitivity, you improve
blood lipids. Insulin is the driver."
Dr. Frank Sacks, a professor of nutrition at the Harvard School of
Public Health in Boston, is cautious. "There are certainly substances
in plants that have very strong biological effects, so the concept is
fine," he said.
Not a statin substitute
But people should not rely on cinnamon to replace statin drugs, used
by 20 million Americans to lower cholesterol. "Cinnamon is a lot less
effective than statins," he said. Statins were tested in rigorous
studies on 70,000 people for five years or more." Compared with that,
the research on cinnamon is weak. It's also curious, he said, that the
USDA study found that the beneficial effects of cinnamon lasted for at
least 20 days after people stopped taking it. "I don't know of any
drug or product whose effects persist for 20 days."
On the other hand, Dr. Andrew Greenberg, director of the obesity
metabolism laboratory at Tufts, has reviewed the literature on
cinnamon and is impressed enough to be starting a collaboration with
Anderson, whose preliminary findings he described as "very exciting
and promising."
It's not all good
One note of caution is that coumarin, a substance found in cinnamon,
may trigger cancer in animals. Cinnamon also contains cinnamaldehyde,
which is toxic. But these toxic components are fat-soluble, while the
beneficial ingredient, proanthocyanidin, is water-soluble.
Water-soluble extracts of cinnamon are available in which "all the bad
components are left behind," said Anderson. (Ground cinnamon does
allow both water- and fat-soluble components to be absorbed, but at
the doses recommended, it does far more good than harm, he said;
cinnamon sticks placed in hot water release only water-soluble
components.)
There may be an indirect health benefit to be had from cinnamon, too,
Taiwanese scientists wrote in the July 14 issue of Agriculture and
Food Chemistry. Cinnamon oil, they found, kills mosquito larvae more
effectively than DEET, a common pesticide and mosquito repellent. The
next step is to test it against adult mosquitoes.