Enough has been said since the dawn of human civilization on the importance of women having a suitable diet during and before pregnancy. A new research corroborates the age old belief and indicates the date taken, by a woman when she conceives plays a role in shaping DNA of the child. The study was carried out on women in western Africa. These women have to cope with dietary changes as the region undergoes major seasonal changes. The study findings hold importance for women in any developing country, like India, where a majority of women do not get enough nutrition during pregnancy.
Robert Waterland the author of this study said, “The rainy season is often referred to as 'the hungry season,' and the dry season 'the harvest season. During the rainy season, villagers have a lot more farming labor to do, and they gradually run out of food collected from the previous harvest." He is associated with Baylor College of Medicine. The women in Baylor College of Medicine eat millet, rice, cassava and peanuts in general. However, in rainy months they gorge on more green vegetables akin to spinach, rich in folate.
The researchers observed concentration of nutrients in 84 expectant women who conceived in monsoon months and 83 women who got pregnant in dry season. They also analyzed the DNA of specific genes in infants born to these women when they were a few months old. The genes in toddlers who were conceived in rainy months had an elevated amount of methylation.
Speaking on the subject, Branwen Hennig, another study author said, “Our results represent the first demonstration in humans that a mother's nutritional well-being at the time of conception can change how her child's genes will be interpreted, with a lifelong impact”. He is involved with London School of Hygiene & Tropical Medicine. Earlier researches carried out in animals indicated environmental influences before pregnancy lead to epigenetic developments in the fetus. These epigenetic effects on DNA are said to be permanent.
Environmental influences can have long term epigenetic effects in human females too. The turmoil suffered by Dutch women in the aftermath of World War II famines resulted in them giving birth to undernourished kids. However, Waterman said prior studies could not establish whether environmental factors can cause permanent changes in human DNA.
He added, “It's also important to note that their diet wasn't the only thing that changed — there was more physical activity due to farm labor during the rainy season, which contributed to weight loss during the rainy season and regaining of weight during the dry season. Such changes contribute to what nutrients are circulating within the women." It is yet to be known what long term effects these epigenetic changes can have on humans.