What did the media say?
The media reported that prospective fathers should consider taking folic acid supplements to improve their chances of fathering a child, after a study claimed to have identified a link between high levels of the nutrient in men’s diets and the genetic quality of sperm.
What did the research show?
The current recommended daily intake of folate for men over 19 is 400 micrograms.
US researchers investigated whether normal dietry and supplement intake of folate, zinc and antioxidants – vitamin C, E and B-carotine – affected abnormalities in sperm where a chromosome has been lost or gained, known as aneuploidy.
The 89 men in the study, who were mostly white and middle-aged, had a median daily folate intake of 475 micrograms, were described as healthy and were non-smokers. Subjects completed a detailed daily diet survey and provided a semen sample.
The researchers found men who had the highest intake of folate, between 722 and 1,150 micrograms, had up to 30% lower frequencies of several types of abnormalities than men with lower intakes – disomy X, disomy 21, sex nullisomy and aggregate aneuploidy.
The consistency of the association across several types of aneuploidy suggests the finding is not simply due to chance, claim the authors. However, the study was relatively small and it was hard to ascertain exactly how many men were in the group with the highest folate intake.
The researchers added that they found no consistent links between aneuploidy and different intakes of zinc and the other vitamins included.
What did the researchers say?
Lead author Brenda Eskenazi, professor of maternal and child health and epidemiology at the University of California, said: “We found a statistically significant association between high folate intake and lower sperm aneuploidy.
‘However, this study cannot prove that high folate intake caused the lower sperm aneuploidy levels, only that there is an association. This is the first study of its kind and the results indicate the need for further research, especially a randomised controlled trial, on this topic,’ she said.
Study co-ordinator Ms Suzanne Young added: ‘Increasing folate intake can be as simple as taking a vitamin supplement with at least 400 micrograms of folate or eating breakfast cereal fortified with 100% of the RDA for folic acid. In addition, green leafy vegetables, such as spinach, can have up to 100 micrograms of folate per serving.’
What does this mean for nursing practice?
Dr Allan Pacey, a specialist in male reproduction at the University of Sheffield, said: ‘The story so far suggests that dietary factors won’t help you make any more sperm, but good diet might just improve the quality of the ones that are made.
‘Before couples run out to the chemist and stock up on supplements, I would suggest that they just lead sensible lives and stop smoking, moderate alcohol intake and eat sensibly, making sure they get their five portions of fresh fruit and veg each day,’ he told BBC news online.
‘Because it takes three months to produce sperm, any lifestyle changes should take place well in advance of any attempt to conceive,’ he added.
Human Reproduction online (2008) http//humrep.oxfordjournals.org