Conflicts of interest, sources of funding and
authorship
The authors declare that there are no conflict of interest.
The present study was supported by the AESAN (Spanish
Agency for Food and Nutritional Safety, Spanish
Ministry of Health and Consumer Affairs, Spain) project
(337/2008).
RMO contributed to the study design. LGG-R, PE and
CP-R performed the data collection. LGG-R was
involved in data analysis and interpretation of the
results. LGG-R and RMO contributed to the writing of
the manuscript. All authors critically reviewed the manuscript
and approved the final version submitted for
publication.