Studies found that the famine caused epigentic changes to a gene called IGF2 that is related to growth and development. Those changes suppressed muscle growth in both the children and grandchildren of pregnant women who endured the famine. For these subsequent generations, that suppression led to an increased risk of obesity, heart disease, diabetes and low birth weight.

These findings marked a pivotal moment in epigenetics research – and clearly demonstrated that environmental factors, such as famine, can lead to epigenetic changes in offspring that may have serious implications for their health.

Until this groundbreaking work, most researchers believed epigenetic changes couldn’t be passed down from one generation to the next. Rather, researchers thought epigenetic changes could occur with early-life exposures, such as during gestation – a highly vulnerable period of development. So initial nutritional epigenetic research focused on dietary intake during pregnancy.

The findings from the Dutch Hunger Winter were later supported by animal studies, which allow researchers to control how animals are bred, which can help control for background variables. Another advantage for researchers is that the rats and sheep used in these studies reproduce more quickly than people, allowing for faster results. In addition, researchers can fully control animals’ diets throughout their entire lifespan, allowing for specific aspects of diet to be manipulated and examined. Together, these factors allow researchers to better investigate epigenetic changes in animals than in people.

In one study, researchers exposed pregnant female rats to a commonly used fungicide called vinclozolin. In response to this exposure, the first generation born showed decreased ability to produce sperm, leading to increased male infertility. Critically, these effects, like those of the famine, were passed to subsequent generations.

As monumental as these works are for shaping nutritional epigenetics, they neglected other periods of development and completely ignored the role of fathers in the epigenetic legacy of their offspring. However, a more recent study in sheep showed that a paternal diet supplemented with the amino acid methionine given from birth to weaning affected the growth and reproductive traits of the next three generations. Methionine is an essential amino acid involved in DNA methylation, an example of an epigenetic change.

These studies underscore the enduring impact parents’ diets have on their children and grandchildren. They also serve as a powerful motivator for would-be parents and current parents to make more healthy dietary choices, as the dietary choices parents make affect their children’s diets.

Meeting with a nutrition professional, such as a registered dietitian, can provide evidence-based recommendations for making practical dietary changes for individuals and families.

There are still many unknowns about how diet affects and influences our genes. What research is starting to show about nutritional epigenetics is a powerful and compelling reason to consider making lifestyle changes.

There are many things researchers already know about the Western Diet, which is what many Americans eat. A Western Diet is high in saturated fats, sodium and added sugar, but low in fiber; not surprisingly, Western diets are associated with negative health outcomes, such as obesity, type 2 diabetes, cardiovascular disease and some cancers.

...continued