Science / Medicine : Vitamin C Found to Guard Against Sperm Damage

Vitamin C can protect against sperm damage in humans and thereby reduce the risk of birth defects, according to a new study by molecular biologist Bruce N. Ames and his colleagues at UC Berkeley. The effect is particularly pronounced in men who have abnormally high numbers of defective sperm because they smoke. The discovery is important, Ames said, because of the growing evidence that defective sperm are a larger source of birth defects and miscarriages than defective eggs.

Ames and his colleagues reported Sunday in the Proceedings of the National Academy of Sciences that they are able to directly detect defective DNA--deoxyribonucleic acid, the genetic blueprint of life--in human sperm.

In one group of men, they measured the levels of Vitamin C in seminal fluid and the number of defects in sperm. They found that the number of defects was lower in men with higher levels of Vitamin C.

In a second study, they gave men a controlled diet containing various levels of Vitamin C. They found that when the amount of Vitamin C in the diet was reduced, the number of DNA defects was increased. Restoring the vitamin to the diet reduced the number of defects.