Need another reason to keep your distance from cigarettes? For men, smoking appears to damage their sperm and potentially their offspring, too. Reporting in the journal BJU International, researchers say that men who smoke have a higher percentage of damage to sperm DNA; they had partially and sometimes totally inactive mitochondria, which power cells; and the part of the sperm that releases the very enzymes that enable sperm to penetrate the shell of the ovum was less likely to be intact. Researchers looked at 422 proteins present in sperm, and found that among the smokers, one was absent, 27 underrepresented, and six overrepresented.
The study was small, with researchers analyzing the sperm of only 20 smokers and 20 nonsmokers, but senior author Ricardo Pimenta Bertolla of the São Paulo Federal University tells the New York Times that the message is clear: Smoking has a detrimental impact on a man's ability to produce sperm that will be able to fertilize an egg, and that impact could extend to the fetus. "Sperm with altered DNA may lead to health problems in the offspring," the researchers conclude. MD Magazine notes that researchers think smoking triggers an inflammatory response in the testis and in certain glands that could diminish sperm quality. (Smoking can even damage the DNA of your grandkids.)