Asthma & allergies - are sun and food important?
Vitamin D deficiency and a possible relationship to asthma and allergies came “out of left field” during a research project looking at the links between early childhood nutrition and asthma, says Michael Epton, a Senior Lecturer at Otago University’s Christchurch School of Medicine.
“The main source of Vitamin D in New Zealand is sun exposure. New Zealanders have become very aware of the importance of keeping people out of the sun to prevent cancer.”
“This message has, however, led to a generation of Vitamin D deficient people who could end up with immune-type and other diseases according to new research,” says Dr Epton.
Vitamin D deficiency and a possible relationship to asthma and allergies came “out of left field” during a research project looking at the links between early childhood nutrition and asthma, says Michael Epton, a Senior Lecturer at Otago University’s Christchurch School of Medicine.
“The main source of Vitamin D in New Zealand is sun exposure. New Zealanders have become very aware of the importance of keeping people out of the sun to prevent cancer.”
“This message has, however, led to a generation of Vitamin D deficient people who could end up with immune-type and other diseases according to new research,” says Dr Epton.
People obtain vitamin D from food as well as exposure to the sun. Some countries exposed to low amounts of sunlight fortify foods with Vitamin D but this does not occur in New Zealand.
Nutritionist Scientist Dr Karen Silvers works with Dr Epton to explore the links between early childhood nutrition, breast feeding, asthma and allergies. Dr Silvers’ work is being funded by the Canterbury Medical Research Foundation (CMRF) which supports a number of Canterbury-based research projects.
The 1100 children involved in the childhood asthma study have been followed since their mothers were pregnant and are now between six and ten years old.
“We know about their diet, whether they were breast-fed, what their home environment is like and a variety of other factors that may determine why some children get asthma and allergies.”
The research into diet and asthma revealed that, at the time of birth, many children were deficient in Vitamin D, presumably because of maternal deficiency.
“Vitamin D is fantastically important!” says Dr. Epton. “Being deficient in this vitamin has long been known to cause bone disease, but new research suggests that it may have links with childhood respiratory diseases, eczema and other diseases by altering immune function.”
The researchers have also been studying the effects of breast feeding on the development of asthma and allergies which has been a “very controversial” area of research.
“Some researchers have linked breast feeding to protection from asthma, where others have suggested no protection, or even an increased risk of asthma and allergies. The controversy is most likely to be caused by differences in research methodology, data collection and interpretation,” says Dr Epton.
In the Christchurch study, breast feeding had a “clear protective effect” on respiratory symptoms at the age of 15 months. The researchers are currently studying whether this effect continues through childhood.
“At six-years-old we can tell for certain if a child has developed asthma as it’s possible for children to do breathing tests at this age. The children may have wheezed in the past but now we know which ones actually have asthma,” says Dr Epton.
Asthma is a big problem in New Zealand – more children are admitted to hospital with asthmatic and other respiratory symptoms than any other condition and both asthma and allergies are continuing to increase in this country.
“More than 50 per cent of our children have allergies which places a major burden on families and on society in general,” says Dr Epton.
Full details about the relationship between early childhood nutrition and asthma should be available within the next few months.
Funding from the Canterbury Medical Research Foundation was instrumental in being able to focus part of the research project on nutrition and its effect on the development of asthma, says Dr Epton.
