"Your biological clock is of vital importance"

Our biological clock has far more of an impact on our health than we expect it to. Bert van der Horst, professor of chronobiology & health, has dedicated his life to researching exactly this.

TEXT: Marjolein Stormezand
PHOTOGRAPHY: Antim Wijnaendts van Resandt

Living according to a natural biological clock reduces chances of disease, as well as ensures that medicine – when taken at the right time – might have better effects. Taking all of this into consideration, it’s strange that the medical world doesn’t apply this in practice, according to Ber van der Horst. If it were up to him this would change. Van der Horst’s field of research mostly focuses on the (disruption of the) biological clock, but is much further- reaching than just that: he looks at how the summer and winter times influence our health; he looks at when is the best time to do a chemo session; how does the night – and the daytime – influence the development of premature children. We asked Van der Horst to expand on one of his latest projects: looking into the night-and-day rhythms of the participants in the Volve Ocean Race. A case like that can tell you a lot, says Van der Horst.

Working night shifts is unhealthy
Van der Horst: "A lot of people in our society don’t live in accordance with their biological clock, and the consequences are many. As such we’ve found that for example mice, when exposed to jet lag, run a higher risk of developing breast cancer. We also know now that working night shifts can have negative consequences for one’s health: a higher risk of type-two diabetes, and a higher risk of obesity. The Volve Ocean Race was a perfect case study through which to look into what extreme conditions – as well as a shortage of sleep – can do to a body. We wanted to find the biological markers that show how severe the disruption of the biological clock can be. We’re going to expand on this research during the America’s Cup, the biggest sailing competition in the world. Next to that there are also plans to do this sort of research on nurses at Erasmus MC and with marine-corps trainees. The goal of these projects is to develop a method of measurement that might quantify the negative effects of disrupting one’s biological clock. This in order to help various sectors in developing a schedule to optimise people’s work rhythm, but also avoid the negative effects."

"A lot of people in our society don’t live in accordance with their biological clock, and the consequences are many. As such we’ve found that for example mice, when exposed to jet lag, run a higher risk of developing breast cancer."

The advantages of a 24-hour economy

It bears repeating: the disturbance of the body’s biological clock can cause a lot of stress. With that in mind, it’s safe to say that the measuring system of Van der Horst and his team could be an important tool for company life. Thinking small – but still in the spirit of capitalism: workers who do nightshifts should call in sick less often if there was a system that allowed lining up the biological clock of a person to their work schedule. The chance of psychological complaints like burn-outs – but also higher chances of developing cancer – can be reduced when a circadian rhythm (a biological rhythm, the cycle of which lasts about one day, also known as a 24-hour rhythm) is being upheld without interruptions. Van der Horst sees a great advantage in developing this method with companies in mind. This measurement system can make labour more sustainable in our 24-hour economy. There
has been interest from outsiders, but Van der Horst is surprised as to how tricky it still is to get his research funded – even though
the government and the health council have, for a while now, been working to solve precisely the same issues.

Everyone gets to profit
"Two years ago, three colleagues (Jeffery Hall, Michael Roshbash, and Michael Young) received the Nobel Prize for medicine for their discoveries in and around molecular mechanisms that control the biological clock of both man and animal. At that point I’d hoped perhaps that would increase interest in the field within the Netherlands. Unfortunately, that hasn’t quite been the case – even though the topics are so important. That’s why we at Erasmus MC are currently trying to see whether the option of a crowdfunder is a possible one. Because everyone would get to profit form a research like this, that much is clear."


    Bert van der Horst studied biology at the University of Amsterdam. There he got his doctorate with a research in the Cell Biology department of Erasmus MC, which focused on lysosomal enzyme sialidase. He started his post-doc 1993, as part of the Molecular Genetics department of Erasmus MC, where he set up mouse models for DNA regenerative diseases xeroderma pigmentosum and the Cockayne syndrome – as well as two mammalian homologens of photolyases DNA repair enzymes. These genes (cryptochroom 1 and 2) turned out to function as essential radars in the Circadian rhythm. For this find he received a ZonMW Vici grant, which made up the foundation for a few line of research in chronobiology, and got him his endowed professorship in chronobiology & health. His current research projects focus on the one hand on the relationship between the Circadian clock and cancer, and on the other on long-term effects of living out of synch with your biological clock (for example, when doing night shifts). The goal of this research: the application of methods to avoid/postpone the development of diseases such as cancer, diabetes and cardiovascular diseases – this by means of preventative interventions, with, for example, aligned work schedules. Another goal is to achieve a new clinical approach to cancer therapy (chronotherapy).