(NaturalNews) The controversial chemical bisphenol-A (BPA), already linked to a wide array of health problems, may also increase the risk of asthma in children, according to a study conducted by researchers from the University of Texas Medical Branch, Galveston and published in the journal Environmental Health Perspectives.
BPA is an industrial chemical widely used in the manufacture of hard, clear plastics like those used in water and baby bottles, as well as in resins used to line cans of food, beverages and infant formula. Exposure has been linked to an increased risk of cancer, heart disease, birth defects, and hormonal and reproductive problems. Its use in products for young children has been banned in a number of countries and in three U.S. states.
After years of insisting that the chemical was safe, the FDA recently changed its position and called for more research.
Researchers fed pregnant mice BPA for a week before they were due to give birth, until the mice had a body burden of BPA equivalent to that regularly found in pregnant U.S. women. They then exposed the pups of these mice to a common allergy inducer, and compared their response to that of mice who had not been exposed to BPA in utero. They found a significantly greater asthma reaction in the BPA-exposed mice.
"All four of our indicators of asthma response showed up in the BPA group, much more so than in the pups of the non-exposed mice," co-author Randall Goldblum said.
Steve Georas of the Mary Parkes Center for Asthma, Allergy and Pulmonary Care at the University of Rochester, who was not involved in the study, said he found the results compelling.
"They're using what are probably going to be reasonable estimates of human neonatal exposure, and that seems to have an effect on the developing immune system or sensitivity to asthma," he said. "If you take it together with some epidemiologic studies, I would consider it cause for concern."
Sources for this story include: http://latimesblogs.latimes.com/gre... http://www.businessweek.com/lifesty....
Showing posts with label asthma. Show all posts
Showing posts with label asthma. Show all posts
Thursday, July 1, 2010
Friday, May 28, 2010
Low levels of vitamin D make asthma worse
(NaturalNews) Asthmatics with low levels of vitamin D may suffer more severely from the disease than patients with sufficient levels of the vitamin, according to a study conducted by researchers from National Jewish Health in Denver and published in the American Journal of Respiratory and Critical Care Medicine.
"Our findings suggest that low vitamin D levels are associated with worse asthma," lead researcher E. Rand Sutherland said.
The researchers measured the vitamin D blood levels of 54 asthma patients, along with their lung function, airway hyper-responsiveness and response to steroid drug treatment.
Airway hyper-responsiveness measures the air passages' tendency to constrict, leading to breathing difficulty.
The researchers found that hyper-responsiveness was twice as high in patients with vitamin D levels below 30 nanograms per milliliter, lung function was worse, and the body responded more poorly to steroid therapy.
In addition, the bodies of people with low vitamin D levels produced more or the immune system signaling chemical TNF-alpha, which increases inflammation.
"It may be that vitamin D is acting as a modifier of the immune system or a modifier of steroid response in ways that are relevant to people with asthma," Sutherland said.
"There is a potential that restoring normal vitamin D levels in people with asthma may help improve their asthma."
The study also showed, consistent with prior studies, that overweight or obese participants were significantly more likely to suffer from vitamin D deficiency. Scientists believe that because fat sequesters vitamin D in the body, people with more body fat need higher levels of the vitamin.
Previous studies have shown that being overweight increases the risk of asthma. The new study suggests that vitamin D might at least in part explain that connection.
Asthma treatment also, in turn, increases the risk of vitamin D deficiency.
"It is ... known that glucocorticoids [steroids used in asthma treatment] increase the destruction of vitamin D, thus making patients with asthma at higher risk for vitamin D deficiency, which in turn decreases lung function and makes their disease worse," said Michael F. Holick, of Boston University.
Sources for this story include: www.businessweek.com/lifestyle/cont....
"Our findings suggest that low vitamin D levels are associated with worse asthma," lead researcher E. Rand Sutherland said.
The researchers measured the vitamin D blood levels of 54 asthma patients, along with their lung function, airway hyper-responsiveness and response to steroid drug treatment.
Airway hyper-responsiveness measures the air passages' tendency to constrict, leading to breathing difficulty.
The researchers found that hyper-responsiveness was twice as high in patients with vitamin D levels below 30 nanograms per milliliter, lung function was worse, and the body responded more poorly to steroid therapy.
In addition, the bodies of people with low vitamin D levels produced more or the immune system signaling chemical TNF-alpha, which increases inflammation.
"It may be that vitamin D is acting as a modifier of the immune system or a modifier of steroid response in ways that are relevant to people with asthma," Sutherland said.
"There is a potential that restoring normal vitamin D levels in people with asthma may help improve their asthma."
The study also showed, consistent with prior studies, that overweight or obese participants were significantly more likely to suffer from vitamin D deficiency. Scientists believe that because fat sequesters vitamin D in the body, people with more body fat need higher levels of the vitamin.
Previous studies have shown that being overweight increases the risk of asthma. The new study suggests that vitamin D might at least in part explain that connection.
Asthma treatment also, in turn, increases the risk of vitamin D deficiency.
"It is ... known that glucocorticoids [steroids used in asthma treatment] increase the destruction of vitamin D, thus making patients with asthma at higher risk for vitamin D deficiency, which in turn decreases lung function and makes their disease worse," said Michael F. Holick, of Boston University.
Sources for this story include: www.businessweek.com/lifestyle/cont....
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