»

The sins of the fathers

Let’s face it, when it comes to kids, it’s usually the mother who gets the blame when things go wrong.

There is a wealth of information to show that a woman’s health before conception and during pregnancy is influential to both the short- and long-term health of her children. Moreover, we now know more about potential damage, caused by diet and exposure to toxins, passed down through the genes and so through the generations.

A good example of this is the generational damage caused by the drug thalidomide. Similarly, a study last year found that genetic damage caused by exposure to methoxychlor, widely used during the 1970s as a ‘safer’ replacement for DDT, is still being passed down to our great-grandchildren through the female line.

But in recent years the focus has begun to shift to the father.

Diet & lifestyle
A new study from Harvard School of Public Health got me thinking about all the aspects of our modern lifestyles that can damage a man’s fertility.

The researchers looked at rates of IVF success in relation to fathers’ diets, and found that men who consumed more processed meats such as bacon, sausage and canned meat had less success.

Other evidence suggests that eating a high-fat diet can reduce a man’s sperm count by up to 40% and there is likewise evidence that men who watch TV for 20 or more hours a week have a significantly lower sperm concentration compared with men who do not watch TV.

Recent research found that rates of pregnancy were much lower if the father was obese because embryos generated with sperm from obese men were less healthy and failed to implant into the mother’s uterus. When obese fathers did achieve a pregnancy, the resulting fetus and placenta were both smaller than normal and the fetus was more likely to be developmentally delayed.

Chemical concerns
Last year a European study looked at the direct effects of around 100 common hormone disrupting chemicals on sperm health.

Around one third of thse, including the UV filters like 4-methylbenzylidene camphor (4-MBC) and octyl methoxycinnamate used in sunscreens, and the anti-bacterial agent triclosan used in toothpaste, showed adverse effects including reducing motility. Some parabens and phthalates also showed these harmful effects.

Other evidence suggests that fathers who smoke pass on the DNA damage that smoking causes to their children – raising the risk of cancer. Studies from Europe, China and Australia have likewise identified around a 30% increase in the rate of childhood cancers when fathers smoke prior to conception.

Sperm are vulnerable to oxidative stress, which in turn damages DNA; and both a high-fat diet and smoking are associated with higher levels of oxidative stress.

Still other evidence shows that exposure to pesticides is damaging to male fertility. Most recently exposure to the herbicide Roundup, the active ingredient of which is glyphosate, has been shown to lead to an increase in abnormal sperm formation.

Job exposures too
A recent study involving almost 10,000 children with birth defects linked rates of fetal malformation to the type of work their fathers did.

Overwhelmingly, fathers exposed to solvents and chemicals in the workplace, such as artists, cleaners, hairdressers, scientists, welders, metal and food processing workers see significantly higher rates of a variety of birth defects in their children.

Fertility & the festive season
For would-be dads (and mums) this is timely information because the winter holiday period is a peak time for conception. According to the Office of National Statistics (ONS) more children are born in July in England and Wales than in any other month. Most of those would have been conceived over October and November.

The other months with the highest number of births were (in descending order) October, September and August – corresponding to conceptions between November and February.

Many men still feel that their input begins and ends with conception. Likewise a feeling of being left out of the action is common amongst new fathers.

The truth is that dads are active participants long before conception and their choices and toxic exposures are deeply influential when it comes to their children’s health and well-being.

Pat Thomas, Editor