Robert A Grant1, Frankie Fan, Kar Teoh, Jonathan P Whitehead, Alun Yewlett , Paul Y F Lee
Background; Platelet-rich plasma (PRP) is prepared from autologous blood samples for therapeutic use across many specialities including orthopaedics and regenerative medicine. The increasing use of PRP is underpinned by an intrinsic capacity to release multiple, platelet-derived growth factors at super-physiological concentrations promoting tissue repair. Objectives; Evidence and guidance towards the most efficacious use of PRP is scarce across several domains including: patient pre-optimisation (such as diet or exercise); The purpose of this review was to summarise current knowledge and highlight areas that require further investigation. Study Design & Methods; Two literature searches were conducted on Wednesday 26th May 2021 on Medline and Google Scholar using the keywords: [“PRP” OR “Platelet-rich Plasma” OR “Platelet Rich Plasma”] AND Diet; [“PRP” OR “Platelet-rich Plasma” OR “Platelet Rich Plasma”] AND “Platelet Function”. All relevant papers were reviewed in full and results, where available, are summarised. Results; Significant diet-induced changes in platelet aggregation were found in 5 studies identifying dark chocolate, energy drinks, dietary nitrate, aged garlic extract, and diets high in saturated fats or flavonoids as potential effectors. Of these, all except energy drinks decreased platelet aggregation. Other agents including ketorolac, propacetamol and magnesium were all reported to reduce platelet activation whilst cyclosporin A had the opposite effect. Limited evidence suggests a short-term increase in platelet aggregation and activation following moderate to high intensity exercise, with a subsequent reduction in the longer-term. Conclusions; Patients should be advised to reduce intake of those diets reported to decrease platelet activation. Although energy drinks were found to increase platelet aggregation the causative ingredient has not been identified and other factors (calorie content) should be considered. Further studies are required to identify the active agent(s). We propose that ketorolac, propacetamol and magnesium be added to drugs, use of which are advised against prior to PRP collection. The potential for cyclosporin A to be used as an agent to increase platelet activity should be examined in clinical trials where safety outcomes are thoroughly assessed. Evidence detailing the effect of exercise on platelet activity and function is inconclusive and further studies, including measurement of platelet count, aggregation and release of growth factors, are recommended.