July 15, 2008 (New York) -- Pregnant women who eat nuts or nut products such as
peanut butter every day during pregnancy may increase their offspring's chances
of developing asthma by nearly 50%, compared with women who rarely or never
consume nut products during pregnancy.
The increased risk is evident for the child's first eight years, according
to a new study in the July issue of the American Journal of Respiratory and
Critical Care Medicine.
"Daily versus rare consumption of nut products -- which we assumed was
largely peanut butter -- was consistently and positively associated with childhood asthma symptoms, including wheeze, dyspnea
[shortness of breath], doctor diagnosed asthma and asthma-associated steroid
use," conclude the study researchers, who were led by Saskia M. Willers,
MSc, an epidemiologist at Utrecht University, the Netherlands.
The researchers caution that more study is needed to confirm these findings
before issuing any recommendations regarding pregnant women and eating nut
products. Exactly how eating peanut butter or nut products daily during
pregnancy may affect offspring's risk of developing asthma is unclear. But the
researchers speculate that maternal factors may influence the development of
the airways and immune system of the developing fetus.
So what's a mom-to-be to do?
Don't panic and make any dramatic changes in your diet
based on this study, stresses Neil Schachter, MD, medical director of
respiratory care at Mount Sinai Medical Center in New York City.
"It's not like if you have a peanut butter sandwich once or twice a week
while you are pregnant that you are doing your child harm," he tells WebMD.
"It's a very interesting study and something to take into account, but it's
just one study and we need a confirmatory study to show this is a real
His best advice? "Until the verdict is in, it's probably a good idea not
to eat peanut products all the time during pregnancy."
Manju Monga, MD, the Berel Held Professor and the division director of
maternal-fetal medicine at the University of Texas Health Sciences Center in
"Moderation is key and there are good nutritional benefits from eating
peanut butter that should not be discounted based on one study," she tells
WebMD. "It is highly unusual to find someone who eats nuts or nut products
every single day during their pregnancy. And this is the only group of women
who had an increased risk of their children developing asthma."
The new study looked at close to 4,000 expectant mothers who completed a
dietary questionnaire that asked how often they consumed vegetables, fresh
fruit, fish, eggs, milk, milk products, nuts, and nut products during the last
month. The researchers also tracked their children's diets at 2 years of age;
their asthma and allergy
symptoms were assessed yearly until they turned 8. The final analysis
included data on 2,832 children and their mothers. Six percent of the mothers
in the study consumed nuts or nut products daily.
Women who consumed nuts and nut products daily during pregnancy were more
likely to have children with wheezing, shortness of breath, use steroids for
asthma, and have symptoms of asthma, than were children of moms who rarely
consumed nuts or nut products while pregnancy. Most study participants reported
rare or regular intake (which according to the definition of the study included
up to six times per week) of nuts or nut products. There was no increased risk
of asthma in the children of moms in that group, the study showed.