Did you know that between 1 and 4% of a healthy man's sperm has a chromosome abnormality? If one of these genetically abnormal sperm were to fertilize an egg, it would either result in miscarriage or a child born with a genetic disability. Having the wrong number of chromosomes is a condition known as aueuploidy. The normal number is 23, and when conception occurs the embryo recieves 23 pairs from each of its parents.
The most common abnormalities occur with chromosomes X, Y and 21. For instance, a duplication of chromosome 21 causes Down Syndrome. Having an extra Y chromosome (XYY) can cause learning difficulties.
Scientists at the University of California (UC) have discovered that men who have a diet low in folate have poorer quality sperm, a higher quantity with chromosome abnormalities. There have been a number of studies similar to this in the past but this is the first to link the health of the father with that of the child.
The study involved 97 healthy, non-smoking men who had no history of fertility problems. Questionnaires were completed to determine the men's diet, and whether they took supplements and vitamins. Semen samples were also taken for comparison.
The results showed that men with a diet richer in folate had up to 20% less abnormal sperm than those men with diets lacking in folate. The research was published in the 19th March edition of the medical journal, Human Reproduction. ('The Association of Folate, Zinc and Antioxident Intake With Sperm Aneuploidy In Healthy Non-smoking Men', S.S Young, B. Eskenazi, F.M Marchetti, G.Block and A.J Wyrobek).
The health of the mother has always been emphasised as a necessity to produce a healthy baby. In the UK, women planning a family are advised by the UK Department of Health to take 400 ug of folic acid daily for three months prior to conception and for the first three months of pregnancy to prevent neural tube defects such as spina bifida and anencephaly (where all of the brain is missing except for the brain stem and the child cannot live outside of the womb). Taking this supplement is a simple and effective way of preventing these conditions. Folic acid is also added to bread and processed cereals. In the USA it is added to many different foodstuffs including flour and grain produce and women are advised to take vitamin supplements for the duration of their pregnancies.
Folic acid is naturally present in beans, lentils, some fruits and leafy green vegetables like cabbage and spinach. Men who ate a higher proportion of these had less risk of producing children with defects and their wives had less risk of miscarriage as a result.
So now there is a question mark over whether men should also take folic acid supplements prior to conception. The new research suggests their health is just as vital to the child as is the mother's health.
A further clinical study is planned to determine whether folic acid supplements would have a definite medical benefit for men.