X-Message-Number: 27616
Date: Tue, 14 Feb 2006 18:49:32 -0800 (PST)
From: Doug Skrecky <>
Subject: a grapefruit-a-day may keep the doctor away

Red Grapefruit Appears To Lower Cholesterol, Fight Heart Disease

A grapefruit a day - particularly the red variety - can help keep heart
disease at bay, according to a new study by Israeli researchers. In a
controlled study group of patients with heart disease, the scientists
found that feeding some patients the equivalent of one grapefruit daily
significantly reduced levels of cholesterol in comparison to patients that
did not eat grapefruit. Chronic high blood cholesterol is a major risk
factor for heart disease.
  The study, which strengthens a growing body of evidence supporting the
heart-healthy benefits of eating citrus fruit, was published Feb. 3 on
the website of the American Chemical Society's Journal of Agricultural
and Food Chemistry. The findings come at an appropriate time: The month
of February has been designated as American Heart Month and heart disease
is the number one killer of women in the United States. The study will
appear in the journal's March 22 print issue.
  The study included 57 patients, both men and women, with hyperlipidemia
(high blood cholesterol) who recently had coronary bypass surgery and
whose high lipid levels failed to respond significantly to statin
drugs. Statins are commonly prescribed to lower cholesterol, according to
study leader Shela Gorinstein, Ph.D., a chief scientist at the Hebrew
University of Jerusalem.
  The patients, equally divided into three treatment groups, were given
either a single serving of fresh red grapefruit, white (blond) grapefruit
or no grapefruit, along with regular, balanced meals for 30 consecutive
days. Israeli Jaffa red and white grapefruit varieties, which are
available in the U.S., were used in this study.
  The patients who received either red or white grapefruit showed
significant decreases in blood lipid levels, whereas the patients that
did not eat grapefruit showed no changes in lipid levels, according to
the researchers. Red grapefruit was more effective than white in lowering
lipids, particularly blood triglycerides, a type of cholesterol whose
elevated levels are often associated with heart problems, the researchers
  It is likely that antioxidants in the grapefruits are responsible for
their health benefits, says Gorinstein, adding that the red variety
generally has higher antioxidants than the white. But it's also possible
that red grapefruit may contain unknown chemicals that are responsible
for the observed triglyceride-lowering effect, she says. Additional
studies are planned.
  Both the fresh fruit and the juice are believed to be equally
beneficial, Gorinstein and her associates say. One cup of fresh
grapefruit is roughly equivalent to half a cup of juice.
  Grapefruit is known to interact with certain medications -sometimes
adversely - so the researchers caution people on prescription medication
to consult with their doctor or pharmacist to determine whether their
medicine will interact before consuming grapefruit products. Appropriate
exercise, well-balanced nutrition and avoidance of tobacco also are
important factors in reducing the risk of heart disease, health experts

J. Agric. Food Chem., ASAP Article 10.1021/jf058171g S0021-8561(05)08171-9
Web Release Date: February 3, 2006
Red Grapefruit Positively Influences Serum Triglyceride Level in Patients
Suffering from Coronary Atherosclerosis: Studies in Vitro and in Humans
Shela Gorinstein,* Abraham Caspi, Imanuel Libman, Henry Tzvi Lerner,
Dejian Huang, Hanna Leontowicz,# Maria Leontowicz,# Zev Tashma, Elena
Katrich, Shengbao Feng, and Simon Trakhtenberg
  The contents of the bioactive compounds in red and blond grapefruits
and their influence on humans suffering from hypertriglyceridemia were
studied. It was found that red grapefruit has a higher content of
bioactive compounds and a higher antioxidant potential than blond
grapefruit, determined by oxygen radical scavenging capacity,
1,1-diphenyl-2-picrylhydrazyl, carotenoid bleaching, and Folin-Ciocalteu
assays. Fifty-seven hyperlipidemic patients, ages 39-72 years, after
coronary bypass surgery, recruited from the Institute's pool of
volunteers, were randomly divided into three equal in number
(19) groups: two experimental (red and blond groups) and one control
group (CG). During 30 consecutive days of the investigation the diets of
the patients of the red and blond dietary groups were daily supplemented
with one equal in weight fresh red or blond grapefruit,
respectively. Before and after this trial, serum lipid levels of all
fractions and serum antioxidant activity were determined. It was found
that serum lipid levels in patients of the red and blond groups versus
the CG after treatment were decreased: (a) total cholesterol, 6.69 versus
7.92 mmol/L, 15.5%, and 7.32 versus 7.92 mmol/L, 7.6%,
respectively; (b) low-density lipoprotein cholesterol, 5.01 versus 6.29
mmol/L, 20.3%, and 5.62 versus 6.29 mmol/L, 10.7%,
respectively; (c) triglycerides, 1.69 versus 2.32 mmol/L, 17.2%, and 2.19
versus 2.32 mmol/L, 5.6%, respectively. No changes in the serum lipid
levels in patients of the CG were found. In conclusion, fresh red
grapefruit contains higher quantities of bioactive compounds and has
significantly higher antioxidant potential than blond grapefruit. Diet
supplemented with fresh red grapefruit positively influences serum lipid
levels of all fractions, especially serum triglycerides and also serum
antioxidant activity. The addition of fresh red grapefruit to generally
accepted diets could be beneficial for hyperlipidemic, especially
hypertriglyceridemic, patients suffering from coronary atherosclerosis.


Life Sci. 2005 Sep 23;77(19):2384-97.
Red Star Ruby (Sunrise) and blond qualities of Jaffa grapefruits and
their influence on plasma lipid levels and plasma antioxidant activity in
rats fed with cholesterol-containing and cholesterol-free diets.
Gorinstein S, Leontowicz H, Leontowicz M, Drzewiecki J, Jastrzebski Z,
Tapia MS, Katrich E, Trakhtenberg S.
  Bioactive compounds of peels and peeled red Star Ruby (Sunrise) and
blond qualities of Jaffa grapefruits were analyzed and their antioxidant
potential was assessed. The dietary fibers were determined according to
Prosky et al., the total polyphenol content by Folin-Ciocalteu method and
measured at 765 nm, minerals and trace elements by atomic absorption
spectrometer, phenolic and ascorbic acids by HPLC and the antioxidant
potential by two different antioxidant assays (DPPH and beta-carotene
linoleate model system). It was found that the contents of most studied
bioactive compounds in both qualities are comparable. Only the contents of
total polyphenols and flavonoids were higher in red grapefruits, but not
significant. The antioxidant potentials of red peeled grapefruits and
their peels were significantly higher than of blond peeled grapefruits
and their peels (P<0.05 in both cases). Diets supplemented with peeled red
and blond qualities of Jaffa grapefruits and their peels have increased
the plasma antioxidant capacity and improved plasma lipid levels,
especially in rats fed with cholesterol added diet. In conclusion, both
qualities of Jaffa grapefruits contain high quantities of bioactive
compounds, but the antioxidant potential of red grapefruits is
significantly higher. Diets supplemented with both qualities of Jaffa
grapefruits improve the plasma lipid levels and increase the plasma
antioxidant activity, especially in rats fed with cholesterol added
diets. Jaffa grapefruits, especially their red Star Ruby quality, could be
a valuable supplementation for diseases-preventing diets.

J Agric Food Chem. 2005 Apr 20;53(8):3223-8.
Changes in plasma lipid and antioxidant activity in rats as a result of
naringin and red grapefruit supplementation.
  The aim of this investigation was to compare the influence of naringin
versus red grapefruit juice on plasma lipid levels and plasma antioxidant
activity in rats fed cholesterol-containing and cholesterol-free
diets. The antioxidant activity of a correlated quantity of red
grapefruit juice was higher than that of naringin. Forty-two male Wistar
rats were randomly divided into six groups of 7 named control, naringin,
grapefruit, Chol, Chol/naringin, and Chol/grapefruit. The rats of the
control group were fed basal diet (BD) and 1-2 mL of distilled water. To
the BD of the other five groups were added 0.46-0.92 mg of naringin
dissolved in 1-2 mL of distilled water (naringin), 1-2 mL of red
grapefruit juice (grapefruit), 1% of nonoxidized cholesterol (NOC) and
1-2 mL of distilled water (Chol), 1% of NOC and 0.46-0.92 mg of naringin
in 1-2 mL of water (Chol/naringin), and 1% of NOC and 1-2 mL of red
grapefruit juice (Chol/grapefruit). After 30 days of different feeding,
it was found that diets supplemented with red grapefruit juice and to a
lesser degree with naringin improved the plasma lipid levels mainly in
rats fed cholesterol and increased the plasma antioxidant activity. In
conclusion, naringin is a powerful plasma lipid lowering and plasma
antioxidant activity increasing flavonone. However, fresh red grapefruit
is preferable than naringin: it more effectively influences plasma lipid
levels and plasma antioxidant activity and, therefore, could be used as a
valuable supplement for disease-preventing diets.

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