A man used to believe his future children were safe as long as he had good genes, regardless of his lifestyle. Turns out a father can pass on both, according to a new study published in the journal, Nature Communications.
Researchers found that a father's diet in the months leading up to conception can affect the expression of particular genes in his offspring, and potentially result in birth defects, cancer, diabetes, and heart disease, the Los Angeles Times reported.
"It's always put on the mother that it's her health that determines the health of the baby," said McGill University reproductive biologist and author of the study, Sarah Kimmins. "But our research and that of some other groups is really showing that this is an outdated way of thinking. Guys also need to consider their health, and what they're eating and what they're doing, in terms of the future health of their offspring."
Their theory was based on mice. Males with diets low in folate, or a type of vitamin B strongly emphasized among pregnant women, had offspring whose gene expression was altered in areas relating to the central nervous system, and involved in certain diseases like cancer and diabetes, according to the study.
"If you don't have enough folate, you don't have enough of these methyl groups, and these methyl groups act like tags on the DNA, to tell genes whether they should be really strongly on, on just a little bit or off," said Kimmins, who holds the Canada research chair for epidemiology, reproduction and development. "So if you don't have enough of those biochemical flags, you're going to transmit that to the embryo via the sperm."
Low levels of folate in mice, somewhat ironically, are intended to mimic both a lack of food and obesity, according to the LA Times: those experiencing a food shortage are presumably lacking basic nutrients while those with obesity typically have a difficult time processing the vitamin.
A lack of food among women even way before the baby-making process can affect future offspring, not only in the next generation. In one study, Netherlands women who survived the Nazi-led food imbargo of the 1940s passed on genetic alterations to their children; in another, prenatal exposure to toxic chemicals influenced the genetic expression of individuals two generations later, according to the LA Times.
Scientists still don't understand exactly how folate and diet in general interact to influence genetic expression, but they do know one contributes to the other.
"No, we can't say we can directly track the mechanism, but we can certainly say it's the first time we've documented that food changed the sperm epigenome, which then was linked with developmental genes, and with birth defects," Kimmins said.
