The 62-year-old actress has slammed the modelling industry for its appetite for skinny girls and female magazine editors who encourage the demand.
She added that the fashion industry chose to turn "a blind eye" to the problem.
"I blame my own sex vehemently on this," she said.
"It is women who run the magazines and women who editorialise and women who make the decisions.
"I think it is completely iniquitous to have incredibly skinny girls on the runway. A lot of the girls are horrifically thin and of course they have a problem."
Dame Helen revealed however that she has spent time visiting modelling agencies with her 17-year-old niece, who was rejected and told to lose more weight.
"Every modelling agency told her she would have to lose weight and I felt so guilty because she really did not have to," she added.
