Study leader Dr Myriam Afeiche, from the Harvard School of Public Health in the USA, said: 'We found that processed meat intake was associated with lower semen quality and fish was to higher semen quality'.
Researchers examined sperm samples from 156 men in couples who were undergoing fertility treatment at Massachusetts General Hospital. The men were also questioned about their eating habits including how often they ate processed meats and fish.
Men who regularly consumed bacon and other processed meats had lower sperm quality than those who ate smaller amounts. The study also found that those who ate white fish at least every other day had significantly more normally-shaped sperm cells. Added to this, sperm counts were significantly higher for men who regularly ate dark meat fish such as salmon and tuna. Dr Afeiche said that it is still unclear how these foods might affect sperm count and morphology.
Dr Allan Pacey, chairman of the British Fertility Society and senior lecturer in andrology at the University of Sheffield warned that the results should not be over-interpreted. 'This may be a real effect, but the study is small and we know that accurately measuring sperm size and shape in the laboratory is fraught with error', he said.
Dr Mark Bowman, president of the Fertility Society of Australia also noted that sperm morphology is a complicated area. 'Not all different looking sperm are actually abnormal sperm', he told ABC News.
The findings were presented this week at the annual meeting of American Society for Reproductive Medicine in Boston. The study should be considered as provisional as the results have not yet been published in a peer-reviewed journal
Dr Pacey said that it is well-established that a healthy diet could improve male fertility but it is still unclear if specific foods could lead to reduced sperm quality. 'It is already known that high intake of processed meat is linked to other health issues and so advising men to limit their intake of processed food may improve their health generally as well as possibly be good for their fertility', he added.