An apple a day

Marc Rowe sent this in; his commentary opens it.



Here is a scientific literature review of apples and health. I have pulled
out of the extensive review the abstract-summaries and conclusions so you
can get the trend of the scientific evidence that has accumulated. We used
ground up apple peels after intestinal transplantation and in children with
intestinal failure and because of peels contain a large amount of pectin, a
soluble fiber that protects the intestinal barrier. Take home message is- an
apple a day (with the peels) actually may actually keep the doctor away.
Marc .


Apple phytochemicals and their health benefits
Jeanelle Boyer and Rui Hai Liu
Department of Food Science and Institute of Comparative and Environmental
Toxicology, Cornell University, Ithaca, New York 14853-7201 USA
Abstract
Evidence suggests that a diet high in fruits and vegetables may decrease the
risk of chronic diseases, such as cardiovascular disease and cancer, and
phytochemicals including phenolics, flavonoids and carotenoids from fruits
and vegetables may play a key role in reducing chronic disease risk. Apples
are a widely consumed, rich source of phytochemicals, and epidemiological
studies have linked the consumption of apples with reduced risk of some
cancers, cardiovascular disease, asthma, and diabetes. In the laboratory,
apples have been found to have very strong antioxidant activity, inhibit
cancer cell proliferation, decrease lipid oxidation, and lower cholesterol.
Apples contain a variety of phytochemicals, including quercetin, catechin,
phloridzin and chlorogenic acid, all of which are strong antioxidants. The
phytochemical composition of apples varies greatly between different
varieties of apples, and there are also small changes in phytochemicals
during the maturation and ripening of the fruit. Storage has little to no
effect on apple phytochemicals, but processing can greatly affect apple
phytochemicals. While extensive research exists, a literature review of the
health benefits of apples and their phytochemicals has not been compiled to
summarize this work. The purpose of this paper is to review the most recent
literature regarding the health benefits of apples and their phytochemicals,
phytochemical bioavailability and antioxidant behavior, and the effects of
variety, ripening, storage and processing on apple phytochemicals.
Summary-epidemiology evidence
Based on these epidemiological studies, it appears that apples may play a
large role in reducing the risk of a wide variety of chronic disease and
maintaining a healthy lifestyle in general. Of the papers reviewed, apples
were most consistently associated with reduced risk of cancer, heart
disease, asthma, and type II diabetes when compared to other fruits and
vegetables and other sources of flavonoids. Apple consumption was also
positively associated with increased lung function and increased weight
loss. Partially because of such strong epidemiological evidence supporting
the health benefits in apples, there is increasing research using animal and
in vitro models that attempts to more clearly explain these health benefits.
Summary animal studies
Overall, the animal studies and in vitro work begin to define mechanisms by
which apples may help prevent chronic disease. First, the strong antioxidant
activity of apples may help prevent lipid and DNA oxidation. Cancer cell
culture work has demonstrated that apples inhibit cell proliferation in
vitro, which may contribute to the association of apple intake with
decreased cancer risk. Apples significantly lowered lipid oxidation both in
humans and rats and lowered cholesterol in humans. These effects, which may
be attributed to both the phenolics and the dietary fiber found in apples,
may partially explain the inverse association of apple intake and risk of
cardiovascular disease.
Conclusion
In numerous epidemiological studies, apples have been associated with a
decreased risk of chronic diseases such as cardiovascular disease, cancer,
and asthma. In vitro and animal studies have demonstrated that apples have
high antioxidant activity, can inhibit cancer cell proliferation, decrease
lipid oxidation, and lower cholesterol, potentially explaining their role in
reducing risk of chronic disease. Apples contain a wide variety of
phytochemicals, many of which have been found to have strong antioxidant
activity and anticancer activity. The interaction of the many apple
phytochemicals warrants more study as researchers attempt to further explain
the mechanism behind the apple's ability to reduce risk of chronic disease.
Recent research has shown that apples do contain bioavailable
phytochemicals, although more work is needed to better understand the
bioavailability of phytochemicals within the apple matrix as opposed to pure
phytochemicals.
Many factors affect the phytochemical profile of apples, and are important
to consider as one attempts to understand and maximize the health benefits
of apples. Phytochemical concentrations vary greatly between different
cultivars. The level of some phytochemicals varies during maturation of the
fruits in response to available light, stage of fruit development and to
some types of fertilization. In general, storage of apples does not seem to
greatly affect apple phytochemicals, but the processing of apples for juice
results in a very significant decrease in phenolics. Processed apple peels
retain their phenolic and flavonoid compounds activity and therefore may be
used as a value-added ingredient with potent antioxidant activity.
The potential health benefits of apples are numerous. Regular consumption of
fruits and vegetables, including apples, as part of a healthy diet may aid
in the prevention of chronic disease and maintenance of good health.
and maintenance of good health.