An interventional study of Christmas cookies (home-made) in Blood Donation, sponsored by Medical University of Vienna. Not yet recruiting at 1 site in Austria. Open to participants aged 18 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by Medical University of Vienna · Not applicable, Interventional, and Supportive care
This study aims to evaluate the effects of glucose consumption (in the form of Christmas cookies) on platelet function, as well as the motivation and willingness of healthy platelet donors.The main hypothesis is that consuming Christmas cookies before platelet donation can improve platelet function in vitro and increase donor satisfaction.
This is a double-blinded, prospective, crossover interventional study. Participants (regular platelet donors at the department of Transfusion Medicine and Cell Therapy, Medical University of Vienna) must donate twice during the study period, while receiving either one or multiple (up to ten) Christmas cookies.
Before and after each donation, participants will be asked to complete a questionnaire on their satisfaction with platelet donations. Platelet function will be analyzed using a Platelet Function Analyzer (PFA-100) before and after each donation. In selected cases, Light Transmission Aggregometry of Born (LTA) will be used to analyze blood samples from the participants and the platelet concentrate before and after the donation.
The study period will last from November 6, 2026, to December 24, 2026. Participants must be between 18 and 70 years old and should not have any food intolerances or allergies. Furthermore, humorless participants will be excluded using a specifically designed questionnaire.
A stable supply of blood products (e.g. platelet concentrates) is of great importance for a functioning healthcare system; this supply depends on healthy, voluntary donors. In the production of platelet concentrates, there are various factors that can affect the concentrate itself. For example, after taking certain pain relievers, such as ibuprofen or aspirin, a person must not donate for a certain period of time, as this would impair the function of the platelets in the concentrate. However, it has not yet been sufficiently investigated whether there are factors prior to a platelet donation that can improve platelet function.
It is well known that high blood sugar levels affect platelet function and thus lead to increased platelet activation. This raises the question of whether consuming foods containing glucose-such as Christmas cookies-can also produce this effect. Another aspect of supply security is the willingness to donate. An adequate supply of blood products cannot be guaranteed if the number of blood donors declines. It is therefore essential to increase donor motivation, especially among young and healthy donors. The purpose of this clinical study is therefore to investigate the effects of glucose in the form of homemade Christmas cookies on platelet function and donor satisfaction. The cookies administered will be of various types, but their sugar content will be similar to ensure better comparability. In addition, this study aims to analyze the effects on potential side effects of platelet donation.
This double-blinded, prospective interventional clinical trial with a crossover design is being conducted at the General Hospital in Vienna, Austria, Department of Transfusion Medicine and Cell Therapy, and a total of approximately 42 people will participate. The trial will take place between November 6, 2026, and December 24, 2026.
Participating donors will donate a total of two times within the study period: once after consuming a single Christmas cookie before the donation (corresponding to the control group-not providing a Christmas cookie would be unacceptable for ethical reasons during the pre-Christmas period) and once after consuming a higher number of cookies (up to 10). Whether the donor consumes one cookie first or the maximum number is determined by a physical random number generator. The study physicians are not informed of the assignment to the respective group. The cookies are ultimately served by an independent person. The last meal should be consumed approximately 2 hours before the start of apheresis to ensure a similar time interval between the last meal and the administration of the cookies in all participants; platelet donation on an empty stomach is not recommended for donor safety reasons.
Donors fill out the usual donor questionnaire before donating, as well as the additional donor satisfaction questionnaire. The donation is then carried out as usual. At the end of the donation, the donor is given another short questionnaire that assesses donor satisfaction and side effects and is asked to fill it out. Platelet function is assessed using a Platelet Function Analyzer (PFA) and, for a subset of donations, light transmission aggregometry (LTA) immediately before and immediately after the donation. Samples are collected as part of the routine blood draws performed during the donation. Additionally, for donors who underwent light transmission aggregometry, a repeat sample is taken from the apheresis product after the donation.
Medical University of Vienna is the lead sponsor of 1,105 studies on the registry; 182 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
High number of cookies (up to ten)
Dietary Supplement: Christmas cookies (home-made)
Low number of cookies (one)
Dietary Supplement: Christmas cookies (home-made)
Participants will get cookies (either one or up to ten) before platelet donation
Change in platelet function after consumption of Christmas cookies
Change in platelet function after consumption of Christmas cookies
Time frame: 2 hours after cookie consumption (after platelet donation)
Change in happiness after consumption of Christmas cookies
Change in happiness after consumption of Christmas cookies
Time frame: 2 hours after cookie consumption (after platelet donation)
Change in side effects of platelet donation after consumption of Christmas cookies
Change in side effects of platelet donation after consumption of Christmas cookies
Time frame: 2 hours after cookie consumption (after platelet donation)
Plan to share: Yes — Anonymized data will be shared on a single-datapoint level.
Supporting information: Study protocol, Informed consent form, Analytic code
Access criteria: upon reasonable request
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Medical University of Vienna →