Why is fluoride added to drinking water?
"Fluoride was found to significantly reduce tooth decay," Neil Maniar, a professor of public health practice at Northeastern University, told Live Science in an email.
The spread of breast cancer may be inherited
In a large study in Sweden, people who inherited two copies of the spread-associated variant have a 22 percent risk of developing metastasis within 15 years of their original diagnosis, the researchers found.