Grapes have been found to activate genes responsible for antioxidant defense in the heart.
A new study has demonstrated that grapes are able to reduce heart failure associated with chronic high blood pressure by increasing the activity of several genes responsible for antioxidant defense in the heart tissue.
Grapes are a known natural source of antioxidants and other polyphenols, which researchers believe to be responsible for the beneficial effects observed with grape consumption.
This study on hypertensive, heart failure-prone rats uncovered a novel way that grapes exert beneficial effects in the heart: grape intake "turned on" antioxidant defense pathways, increasing the activity of related genes that boost production of glutathione, the most abundant cellular antioxidant in the heart.
Lead investigator E. Mitchell Seymour of the University of Michigan noted that the next phase of the study, which will continue into 2014, will allow his team 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.
"Our hypothesis is that whole grapes will be superior to any individual grape component, in each of the areas being investigated," said Dr. Seymour. "The whole fruit contains hundreds of individual components, which we suspect likely work together to provide a synergistic beneficial effect."
The above story is based on the May 2, 2013 news release by University of Michigan Health System
The research has been published ahead of print in The Journal of Nutritional Biochemistry:
Seymour EM, Bennink MR, Bolling SF. Diet-relevant phytochemical intake affects the cardiac AhR and nrf2 transcriptome and reduces heart failure in hypertensive rats. J Nutr Biochem. 2013 Mar 22. pii: S0955-2863(13)00032-6. doi: 10.1016/j.jnutbio.2013.01.008. [Epub ahead of print]
An estimated 1 billion people worldwide have hypertension, which increases the risk of heart failure by 2 to 3-fold.
Heart failure resulting from chronic hypertension can result in an enlarged heart muscle that becomes thick and rigid (fibrosis), and unable to fill with blood properly (diastolic dysfunction) or pump blood effectively.
Oxidative stress is strongly correlated with heart failure, and deficiency of glutathione is regularly observed in both human and animal models of heart failure. Antioxidant-rich diets, containing lots of fruits and vegetables, consistently correlate with reduced hypertension.