Among people with chronic obstructive pulmonary disease (COPD), those who eat a lot of cured meats are more likely to end up in the hospital second time, Spanish researchers have found.
Dr Judith Garcia-Aymerich of the Centre for Research in Environmental Epidemiology in Barcelona and colleagues tracked 274 people for roughly three years after they were first hospitalised for COPD.
At baseline, the researchers surveyed people's eating habits and identified 23 g of cured meats as the median level of daily consumption – about one slice of ham or half a hot dog.
Of the 138 people below the median, 30% were readmitted to the hospital during the study, compared to 40% in the group that ate higher levels of cured meats.
Nitrites in meat are the culprits
After adjustment for such factors as smoking status and medications, the researchers found that those eating the most cured meat were twice as likely to be readmitted to the hospital as those who ate the least.
"Doubling the risk is fairly substantial," said Dr R. Graham Barr of Columbia University in New York, who was not involved in the new work but has done similar research. "So that tends to make us be more convinced that there may be a true signal."
While there is still no final answer on cause-and-effect, Dr Garcia-Aymerich said the nitrites used as a preservative in the meats might be a culprit.
The authors write in their study, published online in the European Respiratory Journal, that nitrites produce molecules shown to harm the lungs of lab animals.
Limit processed meat consumption
"It suggests there's a biological mechanism by which nitrites can damage the lungs," Dr Barr said. "The question is whether any of that is relevant to people."
Dr Garcia-Aymerich said it's also possible that the salt in cured meats might contribute to problems with COPD, "but we really don't know."
The US Department of Agriculture recommends that people limit their consumption of processed meats. But Dr Barr said the new study is not enough to urge people with COPD to steer completely clear of the products.
(Kerry Grens, Reuters Health, March 2012)
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