(previously published here at www.thebulletin.us)
By: Heather J. Chin, The Bulletin
Mothers-to-be might - or might not - be better off reducing consumption of nut-based foods if they wish to decrease their child's risk of developing asthma.
According to a recent study, pregnant women who daily consumed at least one nut product, like a peanut butter sandwich, had children with a 40- to 60-percent higher risk of developing asthma or asthma-related symptoms within the child's first eight years of life.
Still, researchers don't recommend removing nuts from pregnant womens' diets, since they contain nutrients such as vitamins A, C and E, which previous studies say may have protective properties against asthma development.
"While it is too early to make recommendations of avoidance, it is important for pregnant women to eat healthily," said Dr. Saskia Willers, who led the study at the the Netherlands' University of Utrecht. "What is true for many foods is that too much is never good."
The study observed women who ate nut products "rarely" throughout their pregnancy.
It showed that children whose mothers had previous history of asthma or sensitivity were on a restricted diet and also reported suffering from the condition.
On the other hand, women who ate nut products in moderation did not have children who showed any more risk of asthma development.
In this cohort (group) study, the Dutch researchers examined 4,146 pregnant women who completed diet questionnaires about how often they consumed fruit, vegetables, fish, egg, milk, milk products, nuts and nut products during the previous month. Of the women, 1,327 were atopic, having asthma or allergic sensitivity, and 2,819 were nonatopic, with no pre-existing sensitivity or related condition.
Researchers were able to maintain contact with 80 percent of the mothers and children/families, allowing for a great amount of communication during the process.
The health of the children born to participants was monitored from ages 1 through 8, with complete data available for 2,832 children.
The results found no associations between maternal intake of vegetable, fish, egg, milk or milk products and nut consumption and observed childhood outcomes.
This is the first study to examine the mother's diet while they were pregnant (instead of relying on memory years later) and to track the asthma outcomes past the first five years of life. It was published in the July 15 issue of the American Journal of Respiratory and Critical Care Medicine, which is put out by the American Thoracic Society.
Asthma affects over 20 million adults and more than 9 million children in the U.S. have been diagnosed with it.
Despite the strong study and promising findings, the specific factors during pregnancy and early childhood that cause some children to develop asthma [and allergies] over others is still unclear. One known factor is an inherited genetic predisposition.
"Genes play a large role in whether or not the child is eventually going to develop food, or environmental allergies in the future," Dr. Nora Lin, a pediatric and adult allergist with Allergy and Asthma Specialists in King of Prussia. "The effects of the maternal diet on how those genes play out is a pretty complex issue, but [there has not been much] definitive evidence that what a mom eats will affect the outcome of what the child develops or not."
"We don't know what other things the parents did or were exposed to... what supplements or food or medications ... they were using," said Dr. Jonathan Steinfeld, pediatric pulmonologist at St. Christopher's Hospital for Children. "This is an association study - between eating more nut products and the children being diagnosed with asthma later in life, but this does not imply causation (that it caused the asthma)."
The study would also be difficult to apply to American and other families throughout the world since we have such a variety of genetic makeup, Dr. Steinfeld notes.
"While they did it well and with a large group, it needs to be repeated to be sure that elsewhere in the world, [these findings] are reproducible."
Heather J. Chin can be reached at email@example.com
©The Evening Bulletin 2008