Beetroot Juice and Endothelial function in Men

Measurement of flow-mediated dilatation of the brachial artery in response to forearm occlusion for 5 min (FMD) using ultrasonography is a well-accepted, but investigator-demanding method, to determine endothelial function. Local thermal hyperaemia of the skin measured with a laser Doppler flow imaginer (LTH) is less demanding and may be a suitable alternative to determine endothelial function at frequent intervals. We want to investigate whether LTH correlates with FMD response in a group of healthy non-smoking and smoking men and to what extent LTH can be inhibited by the nitricoxide synthase (NOS) inhibitor L-NMMA applied locally on the skin. In addition we want to replicate the reported improved
FMD response to nitrate-rich beetroot juice and correlate this to the LTH response. Post occlusive reactive hyperaemia (PORH) of the skin is considered to be a measure of microvascular function and is also thought to be correlated to the FMD response. We will also determine the PORH response during this study.

- There is correlation between FMD and LTH.

- Smokers have a lower FMD and LTH response.

- Beetroot juice improves the FMD and PORH response but not the LTH response.

2 research visits with 7 days between visits.

Beetroot juice