A “shocking” documentary about twins: research also in the Netherlands

Two months later, the Netflix documentary “You Are What You Eat: A Double Experiment” shows that the group that started eating plant-based foods improved significantly. These participants had a higher life expectancy, a higher libido, and they lost about two kilograms. Many viewers online said they were shocked by the results.

Dutch twin record

The series is based on more comprehensive research conducted by Stanford University. And twin research is not only carried out there: here there is also the so-called Dutch Twin Registry. Participating twins receive an occasional questionnaire about everything from lifestyle to physical and mental health. A database is created based on all this different data.

Emma van der Dijle and her sister Ross are identical twins and share the record. “It's questions about how often I exercise, whether I smoke, and how I feel,” she says. “I think it's special to be able to contribute to scientific research in this way.”

Environment versus genes

The research revolves around genetics and the role that genes play in mental and physical health. Therefore the results are stored in a database. “Researchers can request data and conduct research on it. This way we discover more and more about the influence of genes.”

“It's a very nice model and easy to understand,” says professor and doctoral student Echo de Geus, of the Dutch Twin Registry. “We put two genetically identical people to a test. This basically answers whether something is due to environment or genetics, in simple language.”

For example, the professor mentions an example of twins, one of whom went into space and the other stayed at home. “Researchers have seen a huge difference in bone density. You can infer from this that environmental influences can change a lot in a person.”

mistake

De Geus wants to clarify the “persistent error.” “When we prove that something is genetic, it doesn't mean that nothing can be done about it.” He cites cholesterol as an example. “Sometimes it's hereditary, and then people think: If it's hereditary, there's nothing you can do about it. Then they give up, even though you can definitely still treat it.”