While it is widely acknowledged that a mother's diet before conception is important, a new study has found that what fathers eat at this crucial time is also important for their future offspring.

Canadian researchers focused on the importance of vitamin B9, also known as folate or folic acid. This is found in a number of foods, such as green leafy vegetables and fortified cereals. However, women often do not get enough of the vitamin in this way so all women of childbearing age are advised to take folic acid supplements at least eight weeks prior to, and 12 weeks after, conception.

This is known to reduce the risk of neural tube defects, such as spina bifida, by up to 70%. The vitamin has also been shown to have a role in reducing the risk of miscarriage.

However, the researchers noted that the way in which a father's diet might influence the development of their future offspring has received little or no attention. They decided to look into this further by focusing on the men's intake of folic acid levels too.

Working with mice, they compared the offspring of fathers who had not consumed enough folic acid with the offspring of fathers who had. They found that the offspring of fathers who had not consumed enough of the B-group vitamin suffered more birth defects than the other offspring.

"We were very surprised to see that there was an almost 30% increase in birth defects in the litters sired by fathers whose levels of folates were insufficient. We saw some pretty severe skeletal abnormalities that included both cranio-facial and spinal deformities," the researchers from McGill University explained.

They pointed out that even though folic acid is now added to a range of foods, such as breads and cereals, ‘fathers who are eating high-fat, fast food diets or who are obese may not be able to use or metabolise folate in the same way as those with adequate levels of the vitamin'.

The researchers insisted that if couples are trying to have a baby, fathers should pay just as much attention to their diet and lifestyle as mothers do.

"Our research suggests that fathers need to think about what they put in their mouths, what they smoke and what they drink and remember they are caretakers of generations to come. If all goes as we hope, our next step will be to work with collaborators at a fertility clinic so that we can start assessing the links in men between diet, being overweight and how this information relates to the health of their children," the researchers added.

Details of these findings are published in the journal, Nature Communications.