We all know that eating fruit and vegetables is healthy. But how do we know that? Because it has been shown by scientific research on nutrition. For example, a study that compares a group of participants who eat a lot of vegetables and a group of participants who eat few vegetables, could elucidate the effect on health of the difference in vegetable intake.

Carrying out a study in a proper, standardised way enables a good comparison of different conditions and interventions. This systematic collection, interpretation, and evaluation of data and to investigate scientific theories and hypotheses is called scientific research.

We will explain this with another example: the positive effect on cholesterol of eating fatty acids contained in fish. This effect can be investigated by comparing a group of participants who eat oily fish (salmon) with a group of participants who eat chicken breast instead of fish. Alternatively, instead of real fish, a tablet containing fatty acids from fish can be given and compared with a tablet without such fatty acids (placebo). The participants do not know what they are getting; they are ‘blind’ in the study. The fact that they do not know which tablet they are receiving means that the study is more objective. If participants do know which group they are in, they might demonstrate healthier behaviour. It may also be the case that all participants in a study behave in a healthier way or feel different; this is called the ‘placebo effect’. In a ‘blind’ study, where participants do not know what they are being given, you ensure that such effects are the same in both groups, and you can be sure that the differences between the groups are caused by the intervention (fatty acids from fish).

Human studies – research studies involving people – can be carried out in various places and in numerous ways. Some studies are carried out at our TNO location in Zeist. We can also equip other locations to enable research. For example, a study was conducted at a supermarket in Almere, where questionnaires and body measurements were performed on site. We also collaborate with organisations that have a special research site, such as Contract Research Organizations or ‘CROs’. In addition, research is carried out in collaboration with the healthcare sector, for example in hospitals or at primary care centres. In an earlier study of people with diabetes, diabetes nurses took the measurements and shared the data with TNO. Another way of doing research that is becoming increasingly popular is through the Internet. One example of a study we conducted entirely online is a coffee study. People registered online and coffee pads were sent to the homes of included participants. One hour after they had consumed the coffee, they did various memory tests on a TNO website. The data were automatically shared with TNO, where they were analysed.

The different ways of doing research have advantages and disadvantages. An advantage of carrying out research at TNO is that the researchers can see how the study is being conducted and if the data is collected properly. However, participants have to come to TNO for such studies. Research from home is, of course, much easier for participants, but conditions are then less controlled and there is more variation in the data.

Are you thinking of registering as a participant, or would you like to know more about participating in a study? Please visit the website of the Central Committee on Research Involving Human Subjects (CCMO), which explains what you need to bear in mind as a participant (also referred to as a research subject): english.ccmo.nl/human-subjects.

Depending on what is to be investigated, a study is set up and it is decided what measurements need to be taken. In one study, only a saliva sample needs to be collected, while in another, blood is taken several times after a participant has drunk a kind of milkshake, so that we can determine how easily a participant processes the contents of the drink. What participating in research entails is therefore different for each study and depends on what is going to be investigated. For this reason, always read carefully the participant information specifically written for the study before you decide to take part.

As already described, various types of research are possible. At TNO, research involving human participants is only possible after the study has been assessed and approved. Relatively simple research may be assessed and checked by TNO itself. An independent, internal review committee has been set up for this purpose. Burdensome research that requires people to adhere to certain intensive lifestyle rules or that involves invasive measurements (such as frequent blood sampling) must be submitted to an external review committee. This so-called Medical Ethics Committee assesses whether the research is relevant, well-designed, safe, and whether it is ethically correct. Research involving human participants is only allowed after approval by a review committee.

If you have any questions about one of the studies, you can ask the associated research staff. The lead scientist is always mentioned in the participant information. Please make sure that all your questions are answered before you agree to participate.

General questions can be submitted here.

If you have any complaints about a study, the participant information also states who you can contact to make the complaint. You can submit your complaint here.

It is important to us that participants take part voluntarily and understand what they are getting involved in. It is therefore especially important for your questions about the study to be answered before you agree to participate. To indicate your voluntary participation, we ask you to sign a consent form. On the form, we draw your attention once again to a number of important features of the study, which we would like you to consciously endorse. By signing these conditions in writing, you confirm your full, voluntary participation and familiarity with the study. By having a TNO researcher co-sign the consent form, we create a mutual agreement, with the TNO researcher signing to state that he or she has explained the research properly and has correctly and fully answered any questions you may have.

Even after your consent, you can always withdraw from the study without giving reasons, should you decide to do so. You are under no obligation to participate.

At the bottom of the homepage, you will find the button ‘Participants wanted’. Clicking on it will give you an overview of studies for which participants are still needed. Please read the information about the study carefully. Whether you can participate in a study depends on the selection criteria for that study.

You can also register for the participant database. You will then receive an e-mail when recruitment starts for a new study. You will find the ‘Register for the participant database’ button at the bottom of the homepage of this website.

After you have signed a consent form, your name will be replaced by a study participant code whenever possible. This ensures that your research data cannot be traced directly back to you. Your data will be stored on a secured server at TNO. Only employees involved in the study have access to the data. If TNO is collaborating with other parties in the study, you will be informed whether these parties have access to any of the data and if so, to what data. An inspector from the Ministry of Health, Welfare and Sport or an auditor may also check the data for quality control purposes. They are bound by their duty of confidentiality.

If you decide to withdraw from the study and also wish to withdraw your data, TNO will do its best to comply with this wish. This is possible as long as the data have not yet been processed. TNO is not obliged to withdraw data that have already been processed and published.