Unexplained decline in anemia is welcome
The National Health and Nutrition Examination Surveys (NHANES) from the above time frames provided the CDC's Sarah E. Cusick, PhD, and her team with data on recent changes in anemia rates. The investigators found that the prevalence of all-cause anemia fell from 10.8% to 6.9% among women and from 8.0% to 3.6% among children between the first and second survey periods. However, none of the known possible causes of anemia could account for the decrease in total anemia among these two groups.
“This decline was not associated with changes in iron or folate deficiency, inflammation, or high blood lead,” note the study authors (Am J Clin Nutr. 2008;88:1611-1617). Iron deficiency—the predominant known type of anemia among women in both surveys—decreased, but not significantly (from 4.9% to 4.1%), and remained low in children during both the early and late sets of years studied (1.5% and 1.2%, respectively). Similarly, the already low prevalence of high blood lead with anemia didn't change for children from one time period to the next, remaining below 1%.