Druiven voor een gezond hart*
Uit een studie weliswaar met ratten blijkt dat druiven niet alleen lekker doch ook heel gezond voor het hart kunnen zijn. Alle gebruikte ratten waren zodanig gekweekt dat ze gevoelig waren voor zout en daardoor hoge bloeddruk konden krijgen. De ratten werden verdeeld in drie groepen. Allemaal kregen ze een zoutig dieet al dan niet aangevuld met poeder van blauwe en witte druiven of een medicijn ter verlaging van de bloeddruk of niets extra. Zowel de groep met de druiven als het medicijn hadden een duidelijke verlaging van de bloeddruk in vergelijking met de groep ratten zonder iets extra. Doch de ratten in de medicijngroep hadden geen bescherming opgebouwd tegen mogelijke problemen met hun hart. Zo hadden de ratten met de druiven in hun voeding een duidelijk betere hartfunctie, minder ontstekingen in het lichaam en minder tekens van hartspierschade.
Study Finds Grapes Offer a Bunch of Ways to Help Hearts
Love grapes? Hate heart disease risk factors? Here's good news for you: University of Michigan Cardiovascular research suggests eating grapes could lower blood pressure, help heal signs of heart muscle damage and improve heart function.
Just published in the Journal of Gerontology: Biological Sciences, the study concludes grapes potentially could dramatically reduce the risk of cardiovascular disease. The reason? The scientists think it’s most likely due to the high level of naturally occurring antioxidants called phytochemicals present in grapes. Phytochemicals have consistently been shown in other studies, including earlier University of Michigan research, to reduce potentially harmful cell-damaging free radical activity in the body.
Although the study was performed in laboratory rats bred especially to have salt-sensitive high blood pressure, the researchers note their findings are very encouraging for people. Their data adds more evidence to a quickly accumulating body of knowledge about the health benefits of
grapes.
"These findings support our theory that something within the grapes themselves has a direct impact on cardiovascular risk, beyond the simple blood pressure-lowering impact that we already know can come from a diet rich in fruits and vegetables," said Mitchell Seymour, M.S., in a statement to the media. Seymour led the research as part of his doctoral work in nutrition science at Michigan State University and manages the University of Michigan Cardioprotection Research
Laboratory.
The scientists looked at the effect of a blend of powdered green, red, and black table grapes that were mixed into the rats’ diet. Then they compared the rats that ate the grape powder-laden meals with control rats who didn’t have any grapes, including some animals who received a small dose of a commonly prescribed blood-pressure medication called hydrazine.
After 18 weeks, the rats that ate the grape-enriched food had lower blood pressure, better heart function, reduced inflammation throughout their bodies, and far less signs of heart muscle damage than the rats fed the otherwise same salty diet but without grapes. What’s more, the rats that received hydrazine with a salty diet also had lower blood pressure but, significantly, their hearts were not protected from damage like those in the grape-supplemented group.
Bottom line: Grapes offered cardioprotective benefits while a widely used drug did
not.
In the press statement, University of Michigan heart surgeon Steven Bolling, M.D., said the rats in the study were not so different from millions of Americans who also have high blood pressure related to diet and who often develop heart failure because of prolonged
hypertension.
"The inevitable downhill sequence to hypertension and heart failure was changed by the addition of grape powder to a high-salt diet," stated Bolling, who is professor of cardiac surgery at the University of Medical School and also heads the University of Michigan Cardioprotection Research Laboratory. "Although there are many natural compounds in the grape powder itself that may have an effect, the things that we think are having an effect against the hypertension may be the flavanoids -- either by direct antioxidant effects, by indirect effects on cell function, or both. These flavanoids are rich in all parts of the grape, including the skin, flesh and
seed.” (December
2008)
