Narrator: This is Science Today. Contrary
to previous studies, researchers at the University
of California, San Francisco found no association
between hair dye and Non-Hodgkin's lymphoma. Elizabeth
Holly, a professor of epidemiology, led the study,
which included over four thousand participants,
most of whom were women.
We looked at all different kinds of hair dye use.
We looked at the temporary colors or hair darkeners,
we looked at semi-permanent colors, we looked at
permanent dyes and we also looked at exclusive use
of each of these products because we wanted to know
if it was one type of a product more than another
that might be related to the incidence of lymphoma.
Narrator: Holly's study also dispelled a
former theory that the dark hair dyes posed a greater
risk of cancer.
Holly: This is a nice New Year's present
for people - to be able to know that when they're
dyeing their hair they don't have to worry about
Non-Hodgkin's lymphoma is the fifth leading
cancer among both men and women - and its incident
rate is increasing every year. For Science Today,
I'm Larissa Branin.