Extrait

Background and study aims Several studies have shown that populations who consume a Mediterranean diet enjoy a degree of protection from heart disease. A link to tomato consumption has been suggested, which could be in part due to the anti-blood-clotting (antiplatelet) properties of tomatoes. Based on extensive research carried out by Provexis Natural Products Limited using the branded tomato extract Fruitflow, a heart healthy fruit juice drink was tested in the UK throughout 2006 under the brand name Sirco. Other commonly consumed foods can also have antiplatelet effects, such as fish oils, garlic and cocoa, but when consumed in normal dietary amounts the antiplatelet effects are often small. For example, you would need to consume 3g of fish oil per day for at least several weeks to have an antiplatelet effect. We are interested in combining mild dietary antiplatelets and Fruitflow to increase their antiplatelet effects. However, most dietary antiplatelets are impractical choices for a study as we are not sure how they work or what dose is required, or the quantities which must be consumed are too high. In addition, we would like to focus our study on acute antiplatelet effects, i.e. effects immediately after consumption of a single dose, and we would like to select an antiplatelet which works in a different way to Fruitflow. The range of dietary antiplatelets with such effects is very limited. Therefore to allow us to begin our research into the interactions of Fruitflow with other antiplatelets, we have selected the commonly used over-the-counter drug aspirin at a low dose as our second antiplatelet. Low-dose aspirin is a common part of daily life for many individuals, and its mechanism of action and dosage requirements are all well established and different to that of Fruitflow. Its use is also not associated with side effects in healthy volunteers over a short time. We wish to investigate the effects of repeated intake of Fruitflow along with a daily dose of aspirin. This will ensure that the effects of aspirin and Fruitflow are likely to overlap over the course of the study day. These data will enable us to judge whether the tomato extract has any additional effects on the clotting system of healthy volunteers when taken with a daily dose of aspirin. Who can participate? Healthy subjects aged 45 - 75 What does the study involve? Participants are randomly allocated to take one of two treatments: either aspirin (plus three placebo [dummy] capsules) taken once per day for seven consecutive days, or an apparently identical placebo capsule set. On day 1, participants provide a blood sample before consuming the first capsule, and the effect of this capsule is assessed after 3 and 5 hours. Participants then depart, taking with them a supply of capsules to be taken once per day for the following seven days. On the morning of day 8, participants return to the study unit and a blood sample is taken to measure the effect of the capsules they had taken for the intervening seven days. The participants then consume 3g of Fruitflow, along with their other capsules. Again, blood samples are taken after 3 and 5 hours, after which the participants are free to leave. All participants undertake this process twice, switching between the aspirin and placebo capsules with a break of 14 days (minimum) in between. What are the possible benefits and risks of participating? Participants are healthy volunteers and as such do not benefit directly from involvement in the study. Participants are informed of the reason for the study, and became involved to help with development of a new functional food which might possibly benefit them in the future. Participants are recompensed for lost time and transport costs. Risks associated with the study are related to blood sampling. Participants with particularly thin/thread veins or whose veins are not clearly palpable are excluded from the study. Attempts at blood sampling are limited to four, in order to prevent activation of the clotting system. All blood samples are taken by an experienced nurse phlebotomist, and a closed syringe system is used for the blood collections, minimising risk of blood contact. Where is the study run from? University of Aberdeen (UK) When is the study starting and how long is it expected to run for? May 2007 to March 2010 Who is funding the study? Investigator initiated and funded Who is the main contact? Dr Niamh O'Kennedy

Critère d'inclusion

• Examination of platelet function and response to potentially beneficial dietary supplements in healthy subjects

Liens

• isrctn
• ictrp