It has been known that grapes are able to reduce heart failure associated with chronic high blood pressure. A US study appearing in the "Journal of Nutritional Biochemistry" has now shown how this effect is achieved: The grapes activate a number of genes that improve the levels of glutathione, the most abundant cellular antioxidant in the heart.
The scientists from the University of Michigan hypertensive, fed heart failure-prone rats a grape-enriched diet for 18 weeks. The results reproduced earlier findings that grape consumption reduced the occurrence of heart muscle enlargement and fibrosis, and improved the diastolic function of the heart. Furthermore, the mechanism of action was uncovered. Grape intake "turned on" antioxidant defense pathways, increasing the activity of related genes that boost production of glutathione.
In the next phase, which will continue into 2014, E. Mitchell Seymour, the head of the study, aims to further define the mechanisms of grape action, and also look at the impact of whole grape intake compared to individual grape phytonutrients on hypertension-associated heart failure. His hypothesis is that whole grapes will be superior to any individual grape component. "The whole fruit contains hundreds of individual components, which we suspect likely work together to provide a synergistic beneficial effect," reasons Seymour.
Seymore, EM. Diet-relevant phytochemical intake affects the cardiac AhR and nrf2 transcriptome and reduces heart failure in hypertensive rats, The Journal of Nutritional Biochemistry - 25 March 2013 (10.1016/j.jnutbio.2013.01.008)
