Narrator: This is Science Today. Women of reproductive age have long been urged by doctors to increase their intake of folic acid to prevent the risk of having children with neural tube defects. But new research by the University of California at Berkeley has found folic acid is just as important for men of reproductive age. Bruce Ames, a professor of molecular and cell biology, says most mutations in the fertilized egg come from the sperm.
Ames: If you have a child, the egg that made that child was made when you were a fetus inside your mother, so the eggs are just sitting there, but the sperm are dividing all the time, so the mutations are occurring in the sperm.
Narrator: And men with folic acid deficiencies over-produce a component of DNA called uracil, which lead to chromosome breaks and subsequent mutations.
Ames: DNA has repair systems always cruising along the DNA looking for trouble, and when one of these systems sees a uracil, it just takes it out of there because normally a uracil comes from some other kind of damage.
Narrator: For Science Today, I'm Larissa Branin.