This tells us that the relationship is way more direct and important
than anyone ever imagined. It makes the lifestyle choice rather
compelling.
Our primitive ancestors were clearly evolved to eat a lot of fruit on
an ongoing basis. Any animal protein was always a bonus and not
always too important. What the animal protein did was plausibly top
off a steady but often irregular diet of plants.
In our world, it is possible to consume a steady diet of fruit,
vegetables and nuts. This strongly suggests that we need to build
our diets around just that and use fish, insects, and meat sparingly
to top off the diet.
We also need to see just how the fruits and vegetables work with what
we are learning about grapes.
May 2, 2013 — A new
study appearing in the Journal of Nutritional
Biochemistry demonstrates that grapes are able to reduce heart
failure associated with chronic high blood pressure (hypertension) 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, funded by
a grant from the National Institutes of Health (NIH), and conducted
at the University of Michigan Health System, 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.
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.
In this study,
conducted at the University of Michigan Health System, hypertensive,
heart failure-prone rats were fed 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.
"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," said lead investigator 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."
Seymour noted that the
next phase of the NIH 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 insights gained
from this research will further the knowledge on grapes and heart
health, but will also provide translational information on the value
of dietary (whole foods) and dietary supplement approaches for
prevention of heart disease stemming from chronic hypertension.
"The NIH grant is
allowing the team at the University of Michigan Medical System to
expand its work in this important area and further highlight the
multi-faceted role of grapes in supporting heart health," said
Kathleen Nave, president of the California Table Grape Commission.
"This work will also provide key insights into the role of whole
fruit versus individual components of a fruit, using grapes as the
benchmark."
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