Lingonberry juice lowers blood pressure of spontaneously hypertensive rats (SHR)

• Lingonberry juice was given for spontaneously hypertensive rats for 8 weeks.
• Lingonberry juice lowered systolic blood pressure of SHR (p = 0.007).
• Endothelium-dependent vascular relaxation was not improved.
• Plasma inflammatory and clinical chemistry markers were slightly affected.

Lingonberries (Vaccinium vitis-idaea) are rich in polyphenols, such as proanthocyanidins, anthocyanins, flavonols and flavanols. Polyphenol-rich foods affect vascular health. We previously described improved endothelium-dependent vascular function as well as anti-inflammatory and anti-atherothrombotic effects in spontaneously hypertensive rats (SHR) fed with lingonberry juice. In the present study, we investigated the effects of lingonberry juice dose on blood pressure, vascular function and vascular inflammation in SHR in an 8 weeks’ study. Diluted (1:5) cold-compressed lingonberry juice was given as drinking fluid ad libitum to 5 week old SHR for 8 weeks. Control group (SHR) and normotensive reference group (Wistar-Kyoto) received tap water. Systolic blood pressure (SBP) was monitored weekly. Function of mesenteric artery rings was assessed in standard organ-bath chambers after 8 weeks. Biochemical and clinical chemistry variables were measured from plasma and urine. Lingonberry juice lowered SBP of SHR (p = 0.007). Endothelium-dependent vascular relaxation was not improved. Lingonberry treatment slightly affected plasma inflammatory markers (reduction of NOx and sICAM-1) and clinical chemistry variables (decreased alkaline phosphatase and increased chloride and calcium levels). In conclusion, Lingonberry juice at small concentrations lowers blood pressure in a long-term treatment in SHR.