When I was expecting both my children, I spent a lot of time worrying. The fears began long before I even became pregnant. Like many mothers-to-be, I was tortured with concerns, and my doctor asked me a lot of the same questions—making me fret even more. Did I have genetic failings that I could pass down? Would my age affect my baby? Was my weight OK? Did I take the right vitamins? Did I get enough exercise? How about my stress level—would my cortisones harm a baby? Was it bad that I ate fish and soft cheeses? Did my daily commute expose me to harmful fumes, which could affect a fetus?
After I was lucky enough to make it through with healthy babies, I tried to put away these fears. But recently I’ve been following scientific studies showing that the power of epigenetics on human life. This brand of genetic research focuses on the idea that circumstances around us (including stress, diet, toxin exposure) can turn genes on and off, potentially affecting an individual for an entire lifetime. In fact, once genes are turned on, researchers believe, they can actually stay that way not only for one person’s life but for future generations as well. One of the outcomes of that work is the idea that a mother’s exposures to toxins could have damaging effects far, far into the future, harming not only her own child but her grandchildren or great-grandchildren. A mother’s worries could carry on for centuries!
So imagine my interest—and, frankly, my sense of welcome surprise—when I read about new studies showing that the father’s genetic material actually has a large effect on the child’s mental and cognitive health. Indeed, disorders including autism, schizophrenia, and bipolar disorder can be passed down by mutations in fathers’ genes.
A recent study followed Icelandic men as they aged. The results were that the age of the father has a direct bearing on the number of genetic flaws passed down to his children. So the dad who fathered a child at 36 passed on twice as many genetic mutations than the one who fathered a child at age 20, and it just went up from there. The Nature article summarizing the work quotes a researcher saying, “The older we are as fathers, the more likely we will pass on our mutations.”
Fathers bequeathed almost four times as many new mutations as mothers. So while we like to talk about women’s “biological clocks,” it is clear now that aging reproductive systems are not just a women’s problem. And just as importantly, epigenetic studies distribute the responsibility for future disease to men, too. They have highlighted the dad’s genetic influence: for example, a Swedish study showed that a man’s diet during pre-puberty could affect heart disease and diabetes levels in both his sons and his grandsons.
I wonder if this new information could change the dynamic for men. Will they question themselves before trying to start late-in-life families, or second families, just as women do? Will they take the measure of their own genetic content more closely before trying for a baby? Will doctors start questioning future fathers about their age and health during prenatal visits? Dads, now it’s your turn to worry, too.
MeredithInk 