YouTube says viewers are spending less time watching conspiracy theory videos. But many still do.

YouTube said Tuesday its policies and enforcement helped reduce the length of time viewers watch videos that advance conspiracies and other debunked theories, as the leading video site responds to criticism regarding its failure to police such content.

The Google-owned company said Tuesday it had pared by 70 percent the average time U.S. viewers spend watching videos that it deems “borderline” content, such as those peddling miracle medical cures or flat-earth conspiracy theories. The announcement follows a change in YouTube’s algorithm, announced in January, seeking to limit how often its software recommended videos espousing fringe views.