Scientists funded by ARS have
discovered that certain compounds in oats hinder the ability of blood
cells to stick to artery walls.
The findings were reported by nutritionist Mohsen Meydani and fellow
scientists at the Jean Mayer USDA Human Nutrition Research Center on
Aging at Tufts University, Boston, Massachusetts. Meydani is director
of the center's Vascular Biology Laboratory.
The oat compounds are called avenanthramides. The research team recently
found that they significantly suppressed adhesive molecules that "glue"
blood cells to artery walls. When blood cells stick toand cause
inflammation ofthe artery wall, plaques build up. That accumulationcalled
atherosclerosiscan eventually block the blood vessel. The suppression
provided by avenanthramides in oats may prevent this narrowing of the
passageways through which blood flows.
To test the compounds' antiatherosclerotic activity, the scientists
purified avenanthramides from oats and exposed them to human arterial
wall cells over a 24-hour period. After observing the mixture under
incubation, Meydani found significant reductions in both the expression
of adhesion molecules and the sticking of blood cells to arterial wall
A Double Benefit
The research findings ramp up oats' already heart-healthy reputationearned
because of their high fiber content. Fiber washes cholesterol from the
digestive system that would otherwise be released into the bloodstream.
Cholesterol is a waxy substance, 85 percent of which is produced by
the bodymainly in the liver and small intestine. That 85 percent
provides the essential cholesterol the body needs, for example, to produce
sex hormones and protect nerve fibers.
The sticking point is that when carrier molecules, called apoproteins,
combine with non-water-soluble cholesterol (meaning it doesn't dissolve
in blood), they form lipoproteins. Low-density lipoprotein (LDL) is
considered "bad" cholesterol that accumulates as it travels
throughout the body. High-density lipoprotein (HDL) actually washes
excess cholesterol from arteries and then ferries it to the liver so
it can be eliminated. Water-soluble fiber in oats is believed to help
reduce the amount of LDL cholesterol circulating in blood.
"Adding oat products as part of an overall healthy diet and cutting
down on high-fat, high-cholesterol foods are important to gaining these
benefits," says Meydani.
His group filed a patent on the function of avenanthramides present
in oats, based on their anti-inflammatory and antiatherogenic effects.
As a grain, oats can be found in foods such as enriched cereals and
breads; as rolled oats, in oatmeal; and as oat bran, in muffins or other
baked foods. Meydani hopes a plant breeder or genetic engineer will
create oats with high levels of avenanthramides.By Rosalie Marion Bliss,
Agricultural Research Service Information Staff.
This research is part of Human Nutrition, an ARS National Program
(#107) described on the World Wide Web at www.nps.ars.usda.gov.
Mohsen Meydani is
with the USDA-ARS Vascular Biology Laboratory, Jean
Mayer USDA Human Nutrition Research Center on Aging at Tufts University,
711 Washington St., Boston, MA 02111-1524; phone (617) 556-3126, fax
"Oats May Keep Arteries Out of Sticky Situations"
was published in the June
2004 issue of Agricultural Research magazine.