Using rats that are engineered to develop high blood pressure (hypertension), scientists from the University of Helsinki and Valio report that berry juices were associated with reductions in levels of compounds linked to inflammation, including monocyte chemoattractant protein 1 (MCP1) and cyclooxygenase 2 (COX2).
In addition, lingonberry juice was linked to significant reductions of biomarkers that are involved in damage to cells called soluble adhesion molecules, and intercellular adhesion molecule (ICAM-1) in particular. It is generally accepted that low circulating levels of ICAM-1 are good, and may contribute to a decrease in the risk of atherosclerosis.
“The present study was, as far as we know, the first long-term in vivo experiment in which mechanisms of favorable vascular effects of Finnish berries were studied at cellular and molecular level focusing on inflammation and thrombosis,” wrote the Finnish researchers in The Journal of Functional Foods.
“The main finding was that long-term consumption of cold-compressed juices from cranberry and lingonberry but less blackcurrant show anti-inflammatory and anti-thrombotic actions in [spontaneously hypertensive rats].”
The study adds to a growing body of science supporting the potential beneficial effects of berry extracts. The study compared the effects of cranberry (Vaccinium oxycoccos), lingonberry (Vaccinium vitis-idaea) and blackcurrant (Ribes nigrum) on various markers of inflammation in spontaneously hypertensive rats.
Animals were given free access to one of the juices for eight weeks, and they consumed an average of 38, 44, and 46 grams of cranberry, lingonberry, and blackcurrant juice per animal per day, respectively. Previous studies have indicated that the average water intake per day for such lab animals is about 26 grams per rat per day.
Results showed that expression of COX2 decreased by at least 50% in the lingonberry and blackcurrant fed animals, while MCP1 levels decreased the most in the lingonberry-fed animals, compared with control animals.
“The positive anti-inflammatory effects cannot be regarded as actions of single phenolic compound, although several flavonoids have been shown to possess anti-inflammatory effects in vitro studies,” explained the researchers.
“In in vivo studies the results are not so evident. However, it could be speculated that the highest content of phenolic compounds and e.g. flavan-3-ols and prosyanidins might partly explain vascular and anti-inflammatory effects of lingonberry.
“Lingonberry juice appears to be the most effective of the tested juices as it was also in improving endothelial vasodilatation.”
Source: The Journal of Functional Foods
Published online ahead of print, doi: 10.1016/j.jff.2012.02.010
“Lingonberry, cranberry and blackcurrant juices affect mRNA expressions of inflammatory and atherothrombotic markers of SHR in a long-term treatment”
Authors: A.S. Kivimaki, P.I. Ehlers, A. Siltari, A.M. Turpeinen, H. Vapaatalo, R. Korpela