Fruit fiber may help protect against second-hand smoke effects
September 1, 2005
A new study finds early life exposure to second-hand
smoke can produce life-long respiratory problems. The
study of 35,000 adult non-smokers in Singapore found
that those who lived with a smoker during childhood
had more respiratory problems, including chronic cough.
Study participants who reported eating more fruit and
soy fiber as adults seemed to be protected against some
of the negative health effects often associated with
early tobacco exposure.
Individuals 18 or younger, living with one or more
smokers, were more than twice as likely to suffer from
chronic dry cough as adults, according to a new study
published by researchers at the National Institute of
Environmental Health Sciences (NIEHS), a part of the
National Institutes of Health, the University of Minnesota,
and the National University of Singapore. This paper,
which appears online in Thorax, is the largest
study to date on the effects of childhood exposure to
environmental tobacco smoke (ETS) on later respiratory
disease, and the first to include data on dietary intake.
This research adds to a growing body of evidence that
exposure to second-hand smoke early in life has health
consequences that can last a lifetime, said Dr. David
Schwartz, Director of the NIEHS. In addition to finding
ways to reduce the exposure of children to tobacco smoke
and other environmental pollutants, we also need to
look for ways to reduce the disease burden.
The data for this study were collected from the Singapore
Chinese Health Study, a population of men and women
of Chinese ethnicity ranging in ages from 45 to 74 at
enrollment, who live in Singapore. The 35,000 non-smokers
provided information regarding ETS before and after
age 18, a medical history including information on respiratory
symptoms of chronic cough, phlegm production and asthma
diagnosis, as well as information on dietary intake.
Chronic cough was defined as occurring on most days
for at least three months of the year and lasting more
than two years in a row. More than 45 percent of the
study participants reported having fathers who smoked,
and 19 percent reported having mothers who smoked. The
researchers found that more smokers in the home during
childhood, was linked to a greater incidence of chronic
cough, and chronic phlegm.
Because we had previously found in this Singaporean
population data suggesting that a diet high in fruit
and soy fiber may reduce the incidence of chronic respiratory
symptoms, we decided to study the impact of fiber on
problems associated with early tobacco exposure, said
NIEHS researcher Stephanie London, M.D. We actually
found that people who ate even a small amount of fruit
fiber had less chronic cough related to environmental
Study participants who ate more than 7.5 grams of fiber
each day had fewer health effects associated with ETS.
This is equivalent to eating about two apples a day.
Dr. London pointed out that the average weight of the
Singapore study participants was 127 lbs. She also added
that most Singaporeans get their fiber from fruits,
vegetables and soy.
Fiber may have beneficial effects on the lung, said
Dr. London. It seems to have the ability to reduce
blood glucose concentrations, reduce inflammation, and
enhance antioxidant processes. All of these may help
to protect the lung against environmental insults, such
as ETS in childhood. However, the possible benefits
of fiber should not lessen the importance of reducing
exposure to environmental tobacco smoke.
NIEHS, a component of the National Institutes of
Health, supports research to understand the effects
of the environment on human health. For more information
about environmental tobacco smoke and other environmental
health topics, please visit our website at http://www.niehs.nih.gov/.
The National Institutes of Health (NIH) — The
Nation’s Medical Research Agency — is comprised
of 27 Institutes and Centers and is a component of
the U. S. Department of Health and Human Services.
It is the primary Federal agency for conducting and
supporting basic, clinical, and translational medical
research, and investigates the causes, treatments,
and cures for both common and rare diseases. For more
information about NIH and its programs, visit http://www.nih.gov.
This is a NIH news release. The original version appears here