Fruit, fibre may protect against childhood exposure to smoking
second-hand smoke as children from some of the long-lasting damage
to their respiratory systems, shows a new study.
The research on around 35,000 adult non-smokers in Singapore demonstrated that those who lived with a smoker during childhood were more than twice as likely to suffer from chronic cough as adults.
But people who ate even a small amount of fruit fibre had less chronic cough as a result of tobacco smoke, revealed the paper, published online in Thorax yesterday (doi:10.1136/thx.2005.042960).
The research team, made up of scientists from the US National Institute of Environmental Health Sciences (NIEHS), the University of Minnesota, and the National University of Singapore, say theirs is the largest study to date on the effects of childhood exposure to environmental tobacco smoke on later respiratory disease, and the first to include data on dietary intake.
They say that as well as finding ways to reduce the exposure of children to tobacco smoke, there is also a need for ways to reduce the disease burden.
Earlier studies have linked fruit consumption to lower incidence of chronic respiratory symptoms. There is also evidence to show that dietary vitamins, like vitamin C, can protect children's respiratory health.
But the new study measured fibre intake later in life. Most Singaporeans get their fibre from fruits, vegetables and soy.
Those adults who ate more than 7.5 grams of fibre each day, the equivalent of about two apples, had fewer health effects associated with environmental tobacco smoke when young.
"Fibre may have beneficial effects on the lung," explained NIEHS researcher Dr Stephanie 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."
The data for the study came from the Singapore Chinese Health Study, a population of Chinese men and women aged from 45 to 74 at enrollment, who live in Singapore.
The 35,000 non-smokers provided information regarding their exposure to smoke before and after age 18, as well as a medical history including information on chronic cough, phlegm production and asthma diagnosis. They also supplied information on dietary intake.
More than 45 per cent of the study participants reported having fathers who smoked, and 19 per cent reported having mothers who smoked.
