By Austin Abramson, MD, FACOG
Looking at recent medical genetics studies, the statement “you are what you eat” should be modified. Perhaps the new phrase should be “You are what you mother eats” since preliminary evidence suggests that the environment within the womb may result in childhood obesity1. A mother’s nutrition during pregnancy has the ability to regulate genes in fetal DNA. The structure of DNA is not changed within the womb, but rather molecular changes occur to turn on or off genetic expression. This relatively new field is called Epigenetics.
A way to better to understand this is to imagine DNA as an apartment building which holds within it our entire genetic footprint. DNA is made up of building blocks or bricks. Within each building there are multiple apartments that have distinct characteristics. Each floor is different from the next. Epigenetics would be the switches within each apartment that turn on/off appliances. The appliances do not change the structure of the building just the functionality.
An international study2 looked at the risk of childhood obesity in 300 newborns. They found the nutritional status of the mother during pregnancy could induce epigenetic changes in newborn DNA and these changes were one of many predictors of childhood obesity at 6-9 years of age. The epigenetic changes were not in DNA structure, only functionality. The hypothesis is that the developing fetus was adapting to the environment it will be born into. Since many factors affect the onset of obesity, this preliminary study and future work can lead to new strategies to better understand the genetics as a component of obesity.
In the meantime seek advice from your physician on how to eat a healthy diet and exercise if you are pregnant. The take away message is simple –eating a healthy diet and engaging in regular physical activity throughout your life sets a good example for the next generation through nature and nurture.