However = ?

ContextL

After growing the worm, Caenorhabditis elegans, in plates soaked in the dye, researchers found the worms lived a remarkable 30 to 70 per cent longer than average. However, the study published in the journal, Nature, demonstrates the dramatic effects the dye has on the biological aging process.

More:

http://www.publicservice.co.uk/news_story.asp?id=15938