Research Hints that Chicken Soup Remedy May Have Scientific
Validity in Reducing Cold Symptoms
With the cold and flu season just around the corner, Americans may welcome
news about a published, well-controlled research study that says chicken
soup may contain a number of substances, including an anti-inflammatory
mechanism, that could ease the symptoms of upper respiratory tract infections.
The suspected benefits of chicken soup were reported centuries ago.
The Egyptian Jewish physician and philosopher, Moshe ben Maimonides, recommended
chicken soup for respiratory tract symptoms in his 12th century writings
which were, in turn, based on earlier Greek writings. But, theres little
in the literature to explain how it works.
A challenge outside of the normal realm of scientific research, and
curiosity about the long-touted folk medicine, first led a University of
Nebraska Medical Center (UNMC) physician/researcher to embark upon an off-beat
study to see if the soup may indeed have medicinal value.
In 1993, Stephen Rennard, M.D., conducted an informal laboratory study
and submitted the results as an abstract mostly because of its amusement
value. Seven years later, his chicken soup research has been officially
published in the Oct. 17 issue of CHEST, the peer-reviewed journal of the
American College of Chest Physicians. It is titled, Chicken Soup Inhibits
Neutrophil Chemotaxis In Vitro.
Dr. Rennard, Larson Professor of Medicine in the Pulmonary and Critical
Care Medicine Section at UNMC, had for years watched his wife, Barbara,
cook her Lithuanian grandmothers chicken soup recipe when a cold was going
around her family of 10.
She told me the soup was good for colds, Dr. Rennard said. Ive heard
that a zillion times. Then I started to think, well, maybe it has some
anti-inflammatory value. Everyones heard this from their mother in many
cultures. No one seems to have a monopoly on the insight of the value of
chicken soup.
Three batches of soup prepared in the home of Dr. Rennard were studied
in the laboratory under controlled conditions. Researchers collected neutrophils
from blood donated by healthy, non-smoking volunteers.
The study focus was to find out if the movement of neutrophils the
most common white cell in the blood that defends the body against infection
would be blocked or reduced by chicken soup. Researchers suspect the
reduction in movement of neutrophils may reduce activity in the upper respiratory
tract that can cause symptoms associated with a cold.
Colds are the result of infection in the upper respiratory tract, which
causes inflammation. Although colds are not completely understood, it is
believed the inflammation contributes to cold symptoms. Dr. Rennard theorized
if soup can stop or reduce inflammation, it might reduce the symptoms of
a cold.
In the laboratory, UNMC scientists diluted the soup and subjected the
neutrophils to several variations of the soup, including vegetables, chicken
and a combination of the ingredients. The team found the movement of neutrophils
were reduced. Samples taken during the initial stages of the soup with
chicken broth alone were not found effective in inhibiting neutrophil movement.
The researchers were not able to identify the exact ingredient or ingredients
in the soup that made it effective against fighting colds but theorize
it may be a combination of ingredients in the soup that work together to
have beneficial effects. All vegetables and the soup had activity, Dr.
Rennard said. I think its the concoction.
Known as Grandmas soup, the recipe includes chicken, onions, sweet
potatoes, parsnips, turnips, carrots, celery stems, parsley, salt and pepper.
For comparison purposes, commercial soups were obtained from a local supermarket
and prepared according to the directions on the label. Many of the soups
had the same inhibitory effect.
A variety of soup preparations were evaluated and found to be variably,
but generally, able to inhibit neutrophil chemotaxis, Dr. Rennard said.
The current study, therefore, presents evidence that chicken soup might
have an anti-inflammatory activity, namely the inhibition of neutrophil
migration.
Researchers noted that Grandmas soup has several unusual features.
It contains strained vegetables. Dr. Rennard noted, however, that the inhibitory
activity was observed with several other recipes that lack the particles
from vegetables. Thus, he said, while the identity of the biologically
active materials is unknown, it seems likely they are water-soluble or
extractable. Pureed carrots or other vegetables are not recommended as
a remedy while chicken soup is.
He said the soup also may improve rehydration and nutrition in the body.
The psychological and physical comfort soup provides may also have a placebo
effect for those who are feeling ill.
Ronald Ertl, research coordinator of the lung biology laboratory at
UNMC, said colleagues working near the lab wondered about the aroma coming
from the lab. It was the only time in my life when I could work in the
lab and taste the samples, Ertl said. The lab shouldnt smell like your
kitchen.
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CHEST is published by the American College of Chest Physicians which
represents 15,000 members who provide clinical respiratory and cardiothoracic
patient care in the United States and throughout the world.
UNMC is the only public academic health science center in the state.
Its educational programs are responsible for training more health professionals
practicing in Nebraska than any other institution. Through its commitment
to research, education, outreach and patient care, UNMC has established
itself as one of the country’s leading centers for research in cancer,
genetics, cardiovascular diseases, neurodegenerative diseases and arthritis.
During the past year, UNMCs research funding increased by 31 percent and
now exceeds $40 million, including more than $25 million in federal funding
from such sources as the National Institutes of Health, the National Science
Foundation, Department of Defense and VeteransAdministration.