Between September 2022 and February 2024, over 10,000 people enrolled in the Luxembourg Healthy Ageing study to take part in the large-scale online survey, which was conducted simultaneously at research centres in Austria, Germany and Spain. Based on their responses, some of the participants were invited to carry out a smell test at home. Some were then invited to an in-person examination at the Luxembourg Research Clinic to investigate potential protective and risk factors for neurodegenerative diseases such as Parkinson’s. We are proud to have achieved, together with you, the important milestone of having recruited over 300 active participants by 2025, who are now being examined annually at our research clinic.

Regardless of whether you completed the original online survey, took part in the smell-test or visited the research clinic, your contribution has already provided us with important information that enables us to address key scientific questions and raise new ones. First results can be found further down in this newsletter.

We are now pleased to announce that we will shortly be launching an online follow-up campaign for all participants of the "Healthy Ageing" study in Luxembourg and the Greater Region. Through this follow-up survey, you will continue to have the opportunity to actively contribute valuable information to research into the risk factors for age-related neurodegenerative diseases and their prevention.

Your continued participation is crucial to the success of the "Healthy Ageing" study. By completing the next online questionnaires, you will help the researchers track changes in health and lifestyle over time. This will enable the identification of new risk or protective factors – some of which may differ between women and men – and the development of better strategies for personalised prevention of neurodegenerative diseases. Another focus of the next phase is to explore if and how people would like to receive information about their risk of developing neurodegenerative diseases. Our "Healthy Ageing" partners in Innsbruck have found that these preferences vary greatly depending on cultural or social background. Given Luxembourg’s multicultural population, this is an important issue that we intend to explore in our upcoming online follow-up survey.

The first follow-up questionnaire focuses specifically on this risk communication and your individual preferences. It takes only about 15 minutes to complete. Two months later, you will receive a second questionnaire containing updated versions of the questions from the original survey, which you will recognise from your initial participation in our "Healthy Ageing" study. By repeating these questions, we can track any changes in your health and lifestyle. These insights are crucial for identifying early risk indicators as well as protective factors, and for further supporting the development and implementation of personalised strategies for healthy ageing. Completing the second questionnaire takes around 20 to 30 minutes.

Participants whose contact details, such as email address or telephone number, have changed since their initial participation should please contact our team at heba@uni.lu or +352 621 789 769 (Mon–Fri, 08:00–17:00). This will enable us to ensure that all participants receive future newsletters or invitations to follow-up surveys, provided they have consented to this in the consent form.

The more than 300 people who came to the Luxembourg Research Clinic for their initial examination and blood sampling will continue to be invited for annual follow-up examinations. At these follow-up appointments, we repeat the examinations from the first visit and take new samples. This helps researchers track changes over time, identify early signs of changes in brain health, and investigate whether previously identified risk factors might play a role. The group of participants examined during annual check-ups at the research clinic also includes 100 people who appear to be at particularly low risk of developing a neurodegenerative disease. Studying this group is crucial for identifying potential preventive factors for these conditions.

Some participants have now attended their annual follow-up examination for the third time, and we would like to thank everyone for the time and effort they continue to invest in our study!

“Every time I come to the research clinic, the clinical team is very friendly and knowledgeable. Knowing that my visits are contributing to research that could help prevent neurodegenerative diseases makes my experience even more meaningful.”

– Ms S., participant in the “Healthy Ageing” study, following her third follow-up appointment.

Our experienced clinical team ensures that your visits to the research clinic run as smoothly and comfortably as possible, and is always available to answer any questions you may have.

As you can see, the "Healthy Ageing" study is still in full swing. In the following sections, we will share information with you about the individual stages of the study to date, as well as some preliminary findings. We will update this information on a regular basis and keep all participants who have given their consent informed of any news via email.

Step 1: The online survey

The first step consisted of a 20- to 30-minute online survey, which was conducted between September 2022 and February 2024. More than 10,000 residents of Luxembourg and the Greater Region aged between 50 and 80 took part in the study, resulting in 8,966 fully completed questionnaires (including 50% women and 50% men). The questionnaires were completed in four languages: German (45%), French (32%), English (22%) and Portuguese (1%).

Step 2: The smell test

Based on the responses to the online questionnaire, our study team invited a subgroup of participants to take part in a smell test at home. The invitation to this test does not imply that these participants are at increased risk of developing a neurodegenerative disease. In fact, our study team invited both people with a low risk and those with an increased risk. In total, the team received over 1,700 smell test results, for which we are very grateful.

One interesting preliminary finding is the personal perception of the sense of smell. The graphs below illustrate that self-reported olfactory function (“My sense of smell is normal” or “My sense of smell is impaired”) does not always correspond to the measured results. Some individuals who perceive their sense of smell as normal nevertheless show a measurable impairment. Conversely, not all individuals who report an impaired sense of smell exhibit a measurable olfactory dysfunction. It should be noted that it is normal for the sense of smell to decline with age and that this is by no means an indication of an underlying medical condition. There are also many other explanations, such as a recent cold or head injury, which can lead to a reduction in the sense of smell.

Overall, this means that more than a third of participants perceived their sense of smell differently from what the results of the smell test suggested. Anyone concerned about their sense of smell should consult their GP.

Steps 3: Examination at the research clinic

Based on the results of the smell tests, over 300 participants were subsequently invited to the research clinic in Luxembourg for a detailed clinical examination and to provide blood samples. This examination comprised the following steps:

• A consultation with a study doctor
• A medical examination
• An additional smell test conducted by our team
• A neuropsychological examination
• Completing various questionnaires (e.g. regarding subjective experiences of everyday life and a questionnaire on psychological well-being)
• A blood sample being taken (e.g. for genetic analysis or to examine biomarkers)

Using these samples and information, researchers can better understand how the brain changes with age and which factors increase or reduce the risk of neurodegenerative diseases. The combination of medical data, neuropsychological tests and biological samples – including genetic analyses – makes it possible to investigate known risk and protective factors in greater detail and to classify individuals into different risk groups.

On this basis, early changes can be identified and groups can be specifically selected for future preventive or interventional studies.

Step 4: Annual follow-up examinations

Participants who were invited to attend examinations at the research clinic will be invited again each year so that any changes in their lifestyle or health can be monitored. In 2026, all participants who completed the first online survey but were not invited for an in-person visit will also be invited to take part in a two-part online follow-up survey.

• Part 1, which will be sent out in July 2026, comprises questionnaires designed to identify participants’ preferences regarding risk communication.
• Part 2, which will follow approximately two months later, is intended to assess changes that have occurred since the original online survey.  

In light of the growing body of research findings, we are constantly seeking new ways in which all participants in the "Healthy Ageing" study – whether at the research clinic or online – can help improve their quality of life through early detection and personalised prevention of neurodegenerative diseases such as Parkinson’s and dementia.

New scientific findings show just how much we ourselves can do to maintain our brain health. A recent study by Livingston et al. (2024) indicates that up to 45% of all cases of dementia could be delayed or prevented if modifiable risk factors – such as hearing loss, high blood pressure, social isolation or lack of physical activity – are addressed at an early stage.

There are also important initiatives in this area in Luxembourg. The Programme for Dementia Prevention helps people to better understand and actively reduce their personal risk. In addition, the Braincoach app offers Luxembourg residents simple, practical tips and information on brain health. Further information and support for brain health is also available through the University of Luxembourg’s new GetBrainHealthy initiative.

Our "Healthy Ageing" study in Luxembourg is part of an international initiative. As part of this initiative, researchers from Luxembourg, Germany, Austria and Spain are working together to investigate the risk factors for neurodegenerative diseases in Europe.

Are you curious to find out how things are progressing at the other sites?

Catalonia, Spain: The recruitment campaign began in June 2022 and almost 14,000 residents aged between 50 and 80 have completed the online questionnaire. The researchers have already invited around 2,600 participants to a smell test and 300 to in-person examinations.

Tyrol, Austria: The campaign began in April 2022; nearly 3,000 residents aged between 50 and 80 have completed the online questionnaire in full. Around 1,600 participants have been invited to take the smell test and around 300 to attend in-person examinations.

Kassel, Germany: The campaign began in January 2022; nearly 8,800 residents aged between 50 and 80 completed the online questionnaire in full. The researchers received 2,700 smell tests and invited 310 participants for a face-to-face assessment. A detailed breakdown of the cohort in Kassel has been published in the journal npj Parkinson’s Disease, and a similar publication by all "Healthy Ageing" partners will follow shortly.

Another highlight of 2025 is the Queen Mary University of London (QMUL) joining the "Healthy Ageing" initiative. QMUL has a similar cohort of around 12,000 people who were surveyed online. 4,000 of them undertook an olfactory test and many donated a small amount of blood from home via an innovative collection system.  This expansion of the "Healthy Ageing" programme will enable even more relevant and scientifically robust findings to be obtained regarding the early stages and risk factors for neurodegeneration.

In addition to the inclusion of QMUL, the "Healthy Ageing" initiative is gaining further international significance through ongoing discussions about the inclusion of additional centres across Europe. This is due, among other things, to the research team’s ongoing efforts to present the programme at international conferences. For example, the team was represented at the Alzheimer’s and Parkinson’s Conference in Vienna in April 2025 and at the Movement Disorder Society conference in Philadelphia in October 2024.

The fight against neurodegenerative diseases is a global concern. That is why our European "Healthy Ageing" study forms part of a global initiative led by the Michael J. Fox Foundation. The aim is to understand the risks associated with neurodegeneration, define prevention strategies and develop better treatment methods. We are particularly proud that Luxembourg’s commitment to Parkinson’s research is recognised on a global scale.

Our National Centre of Excellence in Research on Parkinson’s disease (NCER-PD), a joint initiative of the  Luxembourg Institute of Health (LIH), the Centre Hospitalier de Luxembourg (CHL), the University’s Luxembourg Centre for Systems Biomedicine (LCSB), the Laboratoire National de Santé (LNS), les Hôpitaux Robert Schuman (HRS) and the Centre Hospitalier Emile Mayrisch (CHEM), is one of the 51 clinical centres worlwide participating in the Parkinson’s Progression Markers Initiative (PPMI). This is a groundbreaking observational clinical study funded by the Foundation.

Thanks to this new partnership, we are able to investigate Parkinson’s biomarkers within the population of Luxembourg and the Greater Region, and to monitor individuals at increased risk of developing the disease. This includes, for example, people with a loss of smell or with REM sleep behaviour disorder (RBD). The study involves detailed clinical examinations, brain scans and the collection of samples.

We are therefore delighted that various participants in the "Healthy Ageing" study in Luxembourg are now also eligible to join the PPMI study.  In this context, our team may contact you in the near future to ask whether you are interested in taking part in this groundbreaking initiative. We would greatly appreciate your participation!

Global collaboration

PPMI is a global project that brings together researchers, clinicians and people living with Parkinson’s disease to better understand the condition. By collecting comprehensive data from various sources – including clinical examinations, imaging studies and biological samples (e.g. blood) – PPMI aims to identify biomarkers that can aid in early diagnosis and monitoring of disease progression. The aim of this project is to accelerate the development of new treatments and interventions.

The key to PPMI’s success is collaboration: researchers around the world are pooling their expertise and resources to analyse the extensive dataset generated by the initiative. The initial findings have provided valuable insights into the diverse symptoms of Parkinson’s disease and into potential factors influencing the progression of the disease. The spirit of collaboration driving PPMI demonstrates that joint efforts in the fight against Parkinson’s can make a significant difference.