“Epidemiology is more relevant than ever”

In 2026, the Department of Epidemiology at UM’s Faculty of Health, Medicine and Life Sciences will celebrate its 50th anniversary, making it almost as old as the university itself. Professors Matty Weijenberg and IJmert Kant reflect on how the field has evolved over the years and why it is more important today than ever before.

For many years, epidemiology focused primarily on understanding how chronic and other diseases develop and progress within populations. This is crucial for preventing disease and developing effective treatments. “These days,” Weijenberg says, “we also look at the consequences of chronic diseases and how to reduce their impact.” Kant agrees. “The aim is to ensure that people with chronic diseases can continue to play an active part in the labour market and in society, even as they get older.”

Raising the state pension age is not the answer

Kant is far from enthusiastic about government plans to incrementally raise the state pension age. “All it does is increase inequality among workers,” he says. “For example, average life expectancy in this country is currently 80.5 years for men, but there are considerable differences depending on education level. Men with higher levels of education live on average to 82.9, while those with lower levels of education live to 76.5. The gap becomes even larger when you look at healthy life expectancy. For higher-educated men it’s 69.4 years, compared with just 53.7 for lower-educated men. That’s a difference of more than 15 years.”

Lower-educated men tend to begin experiencing health problems well before retirement. “A general increase in the pension age will only widen that gap,” Kant says. “It would be vastly preferable to offer tailored pension arrangements, allowing people with health problems to retire earlier. That was also the recommendation of the Health Council’s advisory committee ‘Health and Longer Working Lives’. I was a member of that committee, and the advice was partly based on research my team and I conducted on the effects of working longer.”

Weijenberg and Kant each have their own area of expertise within epidemiology. Weijenberg specialises in cancer and molecular epidemiology. “I’m interested in the role of lifestyle in the progression of bowel cancer and subsequent recovery. It’s one of the central themes of my chair and of the EnCoRe study,” she says. “There’s now strong evidence that a healthy lifestyle reduces the risk of developing bowel cancer. Maintaining a healthy weight, exercising regularly, limiting time spent sitting, avoiding alcohol and quitting smoking all play an important role. It also helps to eat less processed and red meat and more fibre-rich foods such as fruit and vegetables.”

What remains less clear is which lifestyle factors can help alleviate problems that arise after treatment for bowel cancer. Symptoms include chronic fatigue and nerve pain in the hands and feet caused by chemotherapy-related nerve damage. “The positive effect that certain lifestyle factors might have is still under-researched, while I think there’s a great deal to be gained there. That’s why I’m studying these factors,” Weijenberg says.

Kant, who recently retired, spent the past years focusing on occupational epidemiology. In 1998, he launched the Maastricht Cohort Study (MCS). Together with his team, he followed 12,000 working people over time to shed light on the prevalence and causes of chronic fatigue. They also studied the influence of work, private life and lifestyle on fatigue, along with the consequences of fatigue for performance, sickness absence and work disability. Over time, the scope of the study was broadened. “We now also investigate how chronic diseases affect people’s work. In other words, can you continue functioning effectively at work and remain in employment when you have a chronic illness?”

Based on findings from the MCS, Kant and his team also developed a questionnaire to identify employees at high risk of future sickness absence. “Organisations can then offer these employees coaching or psychological support at an early stage,” he says. “We conducted two large studies and showed that this strategy reduced sickness absence among the high-risk group by as much as 45%.”