Grapes work to reduce the heart failure that is often associated with chronic high blood pressure via an increased activation of several genes that are responsible for antioxidant defense in heart tissue, new research has found.
It has been known for some time that grapes are a significant natural source of antioxidants and polyphenols, which are theorized to be the compounds behind many of the beneficial health effects that are observed when grapes are added to a diet.
And now, the new research, done at the University of Michigan Health System, has “uncovered a novel way that grapes exert beneficial effects in the heart: influencing gene activities and metabolic pathways that improve the levels of glutathione, the most abundant cellular antioxidant in the heart.”
Glutathione is, essentially, the primary antioxidant that your body produces to prevent cellular damage, among other things. Low glutathione levels are highly associated with almost all chronic diseases, and many developmental diseases. Glutathione is critical to good health. Which is why your body produces about as much of it as it can with the nutrition available.
Back to the research — “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.” And something else that is worth noting, is that even amongst those who consume diets containing many fruits and vegetables, those that exercise and are highly active have considerably higher levels of the antioxidant.
The new research was done by feeding a grape-enriched diet to “hypertensive, heart failure-prone rats” for a period of 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.”
More interestingly though, the mechanism for this all was discovered — increased grape intake ‘activated’ antioxidant defense pathways, which increased the activity of related genes, and greatly boosted the production of glutathione.
“Our earlier studies showed that grapes could protect against the downward spiral of hypertensive heart failure, but just how that was accomplished — the mechanism — was not yet known,” stated primary researcher E. Mitchell Seymour, Ph.D. “The insights gained from our NIH study, including the ability of grapes to influence several genetic pathways related to antioxidant defense, provide further evidence that grapes work on multiple levels to deliver their beneficial effects.”
The study will now be continuing into its second phase, which will attempt to further clarify 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 new research was recently published in the Journal of Nutritional Biochemistry.
Source: University of Michigan Health System
Image Credit: Grapes via Flickr CC; Red Grapes via Flickr CC
