Hair loss triggered by controllable factors like smoking, divorce

There are many factors that doctors say determine hair loss,
including age, genetics and bad nutrition. But new research shows
there's more controllable factors, like smoking, sun exposure and
even divorce. How much hair loss people experience is usually
determined by our genes. For instance, if your grandpa lost all of
his hair at midlife, you could face a similar story. But now,
doctors say we might have some control over hair loss. Researchers
at University Hospitals Case Medical Center in Cleveland, Ohio
studied 150 sets of twins at a twin festival in Twinsburg, Ohio.
Dr. Bahman Guyuron took photos of the identical twins and asked
them a long list of questions: did they smoke, have children,
etc.