BUCKWHEAT |
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Department of Food Science and Human
Nutrition, 259 ERML, 1201 West Gregory Drive, University
of Illinois, Urbana 61801, USA.
Honey has been known to exert significant
in vitro antioxidant activity, in part due to its phenolic
content. However, conclusions that the antioxidants in honey
are or are not efficacious in the human body cannot be reached
if its antioxidant action is not assessed as part of a human
study. In the present study, the acute effect of consumption
of 500 mL of water, water with buckwheat honey, black tea,
black tea with sugar, or black tea with buckwheat honey
on serum oxidative reactions was examined in 25 healthy
men. Antioxidant capacity of human serum samples was measured
using different methods: the oxygen radical absorbance capacity
(ORAC) assay, ex vivo susceptibility of serum lipoprotein
to Cu(2+)-induced oxidation, and the thiobarbituric acid
reactive substances (TBARS) assay. The results showed that
the serum antioxidant capacity determined by ORAC increased
significantly (p < 0.05) by 7% following consumption of
buckwheat honey in water. No significant changes in serum
antioxidant capacity could be established after the consumption
of any of the other beverages. Ex vivo serum lipoprotein
oxidation and TBARS values were not significantly altered
after consumption of any of the five beverages. This study
provides primary evidence of the in vivo antioxidant activity
of buckwheat honey. However, long-term studies and epidemiological
data are necessary to investigate whether honey consumption
can exert overall antioxidant-related health benefits.
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Oriental Hospital, Oriental Medical
College of Daejeon University, 22-5 Daeheung-dong, 301-724,
Daejeon, South Korea.
The anti-allergic action of buckwheat
grain extract (BGE) was investigated using rodent experimental
models. The oral, intraperitoneal and intradermal administration
of BGE significantly inhibited the compound 48/80-induced
vascular permeability documented by Evans blue extravasation.
In addition, BGE showed potent inhibitory effect on passive
cutaneous anaphylaxis (PCA) activated by anti-dinitrophenyl
(DNP) IgE when orally administered. In an in vitro study,
BGE revealed to possess inhibitory potential on the compound
48/80-induced histamine release from rat peritoneal mast
cells (RPMC). Moreover, BGE inhibited the IL-4 and TNF-alpha
mRNA induction by PMA and A23187 in human leukemia mast
cells, HMC-1. Taken together, these results suggest that
anti-allergic action of BGE may be due to the inhibition
of histamine release and cytokine gene _expression in the
mast cells.
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Department of Biochemistry, Amino Up
Chemical Co., Ltd., Sapporo, Hokkaido, Japan.
We have undertaken four basic in vitro
studies and an animal experiment to obtain information about
the antioxidant activities of buckwheat hull extract (BWHE).
In the in vitro studies, BWHE scavenged super oxide anion
produced in the xanthine/xanthine oxidase system (IC50=11.4
microg phenolic compound/ml), and strongly inhibited autoxidation
of linoleic acid (IC50=6.2 microg phenolic compound/ml).
Low-density lipoprotein (LDL) oxidation induced by Cu2+
ion was also protected by BWHE. In the animal experiment,
ddY mice were fed a standard diet supplemented with 0.75%
BWHE for 14 d. In blood, liver and brain of the mice TBARS
and fluorescent substance concentration were significantly
decreased compared with those of non-treated mice. SOD like
activity in serum also significantly rose by BWHE treatment.
BWHE was shown to be effective for protecting biological
systems against various oxidative stresses in vitro, and
to have antioxidant activity in vivo.
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Development, Health Care, Kissei Pharmaceutical
Co., Ltd., Yoshino, Matsumoto 399, Japan.
Buckwheat protein product (BWP) has
a strong hypocholesterolemic activity in rats fed a cholesterol-enriched
diet. In this study, we examined the influence of BWP on
fecal excretion of sterols and nitrogen in rats fed a diet
containing 5 g/kg cholesterol and 1.25 g/kg sodium cholate,
and we examined whether the cholesterol-lowering activity
of BWP is due to its low digestibility. In Experiment 1,
rats fed BWP for 3 wk had significantly lower concentrations
of plasma cholesterol and enhanced excretion of fecal total
neutral sterols and nitrogen compared with rats fed casein.
There was a significant correlation between fecal total
neutral sterols and nitrogen (r = 0.89, P < 0.01). Fecal
excretion of acidic sterols was unaffected by BWP. In Experiment
2, plasma cholesterol in rats fed trypsin-digested BWP for
2 wk was significantly higher than that in rats fed intact
BWP. In Experiment 3, rats were fed BWP, low-molecular-weight
fraction of the digest of BWP (LMF ) or high-molecular-weight
fraction of the digest of BWP (HMF ) for 3 wk. Plasma cholesterol
was lower in the BWP group than in the LMF group (P < 0.05),
whereas that in the HMF group was intermediate. The in vitro
digestibility of BWP with pepsin and pancreatin was significantly
lower than that of casein. The results suggest that the
cholesterol-lowering effect of BWP is mediated by higher
fecal excretion of neutral sterols and that lower digestibility
of BWP is at least partially responsible for the effect.
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CEREALS - ROLLED OATS |
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Second University Clinic of Internal
Medicine, Aarhus Kommune-hospital, Denmark.
Cooking and processing of food may
account for differences in blood glucose and insulin responses
to food with similar contents of carbohydrate, fat, and
protein. The present study was carried out to see if short-term
cooking of rolled oats caused an increase in blood glucose.
Furthermore, we wanted to see if dried fruit could substitute
for some of the starch without deterioration of the postprandial
blood glucose response. We therefore compared the blood
glucose and insulin responses to three isocaloric, carbohydrate
equivalent meals in 11 normal subjects and 9 Type 2 diabetic
patients. Meals composed either of raw rolled oats, oatmeal
porridge or a mixture of raw rolled oats with raisins were
served. In normal subjects, the three meals produced similar
glucose (75 +/- 22, 51 +/- 16 and 71 +/- 23 (+/- SE) mmol
l-1 180 min, respectively) and insulin response curves (3160
+/- 507, 2985 +/- 632 and 2775 +/- 398 mU l-1 180 min, respectively).
Type 2 diabetic patients also showed similar postprandial
blood glucose (515 +/- 95, 531 +/- 83 and 409 +/- 46 mmol
l-1 180 min, respectively) and insulin (5121 +/- 850, 6434
+/- 927 and 6021 +/- 974 mU l-1 180 min, respectively) responses
to the three meals. Thus short-term cooking of rolled oats
has no deleterious effect on blood glucose and insulin responses,
and substitution of 25% of the starch meal with simple sugars
(raisins) did not affect the blood glucose or insulin responses.
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Rolled oats (125 g daily) were substituted
for breakfast cereals and wheat flour in the metabolically
controlled diets of 10 subjects for 3 wk. Fat and energy
intakes in the 2-wk control periods before and after the
oat period were adjusted by addition of an oil with a similar
fatty acid composition to the lipid in the oats. Plasma
total cholesterol concentrations were reduced in seven of
10 subjects, but over the whole group the mean reduction
of 8% was not significant (0.05 less than p less than 0.01).
High-density lipoprotein cholesterol concentrations and
plasma triglyceride levels were unchanged. Fecal fat excretion
was increased by 47% (p less 0.005) and fecal bile acid
excretion by 35% (p less than 0.01) but neutral steroid
excretion was unchanged on the oatmeal diet.
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Commonwealth Scientific & Industrial
Research Organisation Health Sciences and Nutrition, Adelaide,
Australia.
BACKGROUND: Whole-grain cereal foods
including rye have been identified as providing significant
health benefits that do not occur when refined-cereal foods
are ingested. OBJECTIVES: Foods (90 g) containing whole-grain
rye flour and whole-grain wheat flour were compared with
low-fiber refined-cereal foods for their effects on markers
of bowel health and the metabolic markers insulin and glucose.
DESIGN: Three 4-wk interventions were undertaken in a randomized
crossover design with 28 overweight men aged 40-65 y who
had no history of bowel disease. Against a background intake
of 14 g dietary fiber (DF), the men were fed low-fiber cereal
grain foods providing 5 g DF for a total of 19 g DF/d. High-fiber
wheat foods provided 18 g DF, and high-fiber rye foods provided
18 g DF, both giving a total of 32 g DF/d. Fecal samples
(48-h) and fasting and postprandial blood samples were collected
at the end of each period and assayed. RESULTS: Both high-fiber
rye and wheat foods increased fecal output by 33-36% (P
= 0.004) and reduced fecal beta-glucuronidase activity by
29% (P = 0.027). Postprandial plasma insulin was decreased
by 46-49% (P = 0.0001) and postprandial plasma glucose by
16-19% (P = 0.0005). Rye foods were associated with significantly
(P = 0.0001) increased plasma enterolactone (47% and 71%)
and fecal butyrate (26% and 36%), relative to wheat and
low-fiber options, respectively. CONCLUSIONS: High-fiber
rye and wheat food consumption improved several markers
of bowel and metabolic health relative to that of low-fiber
food. Fiber from rye appears more effective than that from
wheat in overall improvement of biomarkers of bowel health.
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Department of Clinical Nutrition, University
of Kuopio, Kuopio, Finland.
BACKGROUND: Fiber and whole-cereal
intakes may protect against hyperinsulinemia and the risk
of type 2 diabetes. OBJECTIVE: The aim was to study whether
the long-term use of high-fiber rye bread and white-wheat
bread modifies glucose and insulin metabolism in healthy
postmenopausal women. DESIGN: The study was a randomized
crossover trial consisting of 8-wk test and 8-wk washout
periods. The subjects were 20 postmenopausal women [macro
x +/- SD age: 59 +/- 6.0 y; body mass index (in kg/m(2)):
27.5 +/- 2.9; baseline fasting serum cholesterol: 6.5 +/-
0.8 mmol/L], of whom 3 had impaired glucose tolerance as
determined by a 2-h oral-glucose-tolerance test. The test
breads were high-fiber rye and white-wheat breads, planned
to make up > or =20% of energy. Fasting blood samples were
collected for the measurement of plasma glucose and insulin
at the beginning and at the end of both bread periods. The
frequently sampled intravenous-glucose-tolerance test was
performed at the run-in and at the end of both bread periods.
The acute insulin response, insulin sensitivity, and glucose
effectiveness were calculated. RESULTS: The rye bread made
up 23.4 +/- 4.3% and wheat bread 26.7 +/- 8.2% of total
energy intake. Compared with that during the run-in period,
the acute insulin response increased significantly more
during the rye bread period (9.9 +/- 24.2%) than during
the wheat bread period (2.8 +/- 36.3%; P = 0.047). Other
measured variables did not change significantly during the
study. CONCLUSIONS: Modification of carbohydrate intake
by high-fiber rye bread did not alter insulin sensitivity
in postmenopausal, hypercholesterolemic women. High-fiber
rye bread appears to enhance insulin secretion, possibly
indicating improvement of b cell function.
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Department of Horticulture, Danish
Institute of Agricultural Sciences, Kirstinebjergvej 10,
DK-5792 Aarslev, Denmark.
Dietary antioxidants that protect
low-density lipoprotein (LDL) from oxidation may help to
prevent atherosclerosis and coronary heart disease. The
antioxidant activities of purified monomeric and dimeric
hydroxycinnamates and of phenolic extracts from rye (whole
grain, bran, and flour) were investigated using an in vitro
copper-catalyzed human LDL oxidation assay. The most abundant
ferulic acid dehydrodimer (diFA) found in rye, 8-O-4-diFA,
was a slightly better antioxidant than ferulic acid and
p-coumaric acid. The antioxidant activity of the 8-5-diFA
was comparable to that of ferulic acid, but neither 5-5-diFA
nor 8-5-benzofuran-diFA inhibited LDL oxidation when added
at 10-40 microM. The antioxidant activity of the monomeric
hydroxycinnamates decreased in the following order: caffeic
acid > sinapic acid > ferulic acid > p-coumaric acid. The
antioxidant activity of rye extracts was significantly correlated
with their total content of monomeric and dimeric hydroxycinnamates,
and the rye bran extract was the most potent. The data suggest
that especially rye bran provides a source of dietary phenolic
antioxidants that may have potential health effects.
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BARLEY |
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Institute of Food Research, Norwich
Research Park, Colney, UK.
It has been suggested that incomplete
digestion of cereal starch explains the low energy values
of certain cereals of large particle size. We used human
subjects with ileostomies to investigate the digestion of
barley and to determine whether the physical form of barley
affects stomal excretion of starch, glucooligosaccharides,
nitrogen, fat, and calculated energy. Only 2 +/- 1% of starch
remained undigested after finely milled barley was eaten,
but after flaked barley was eaten 17 +/- 1% resisted digestion,
partly as oligosaccharides (G1-G10) but largely as intact
unpitted starch granules bound by intact cell walls. The
calculated energy excretion from the stoma was three times
higher after flaked than after milled barley [51.5 decreasing
to 15.3 kJ/g nonstarch polysaccharide (NSP, P < 0.001].
NSP, starch, and fat made almost equal contributions to
the higher energy excretion. It is concluded that possibly
the botanical source of cereals and certainly processing,
other than retrogradation of the starch, are important determinants
of starch digestibility and energy value. Possible clinical
implications are introduced.
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Research Institute, Kagome Co., Ltd.,
Nasu-gun, Tochigi, Japan.
Effects of barley tea drinking on
blood fluidity were evaluated by measuring the passage time
of whole blood with a microchannel array flow analyzer (MC-FAN).
The ingestion of barley tea in 250 mL amounts decreased
the passage time of whole blood, but this did not occur
with the ingestion of the same volume of water. 2,3,5-Trimethyl
pyrazine at the same level as in barley tea also caused
a significantly decreased time of blood passage in vitro.
This suggests that alkylpyrazines may serve as factors affecting
the blood fluidity in barley tea drinking.
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Department of Applied Nutrition and
Food Chemistry, Center for Chemistry and Chemical Engineering,
Lund University, Sweden.
In the present study, we evaluated
whether a low glycemic index (GI) breakfast with lactic
acid bread had an effect on glucose tolerance and insulinemia
at a subsequent high GI lunch meal. A barley bread containing
lactic acid and a reference barley bread were consumed in
the morning after an overnight fast in random order by 10
healthy men and women. Four hours after the breakfasts,
the subjects ate a standardized high GI lunch, and the blood
glucose and insulin responses were measured for the next
3 h. Significant lowerings of the incremental glycemic area
(-23%, P = 0.033) and of the glucose response at 95 min
were found after the lunch meal when the barley bread with
lactic acid was given as a breakfast. At 45 min after the
lunch meal, the insulin level was significantly lower (-21%,
P = 0.045) after the lactic acid bread breakfast, compared
with the barley bread breakfast without lactic acid. We
concluded that barley bread containing lactic acid eaten
at breakfast has the potential to improve second-meal glucose
tolerance at a high GI lunch meal 4 h later.
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Second Department of Medicine, Kurume
University School of Medicine, Fukuoka, Japan.
BACKGROUND: Germinated barley foodstuff
(GBF) has been shown to attenuate intestinal injury in animal
models, largely by increasing luminal short-chain fatty
acid production. AIM: To investigate the safety and efficacy
of GBF in the treatment of ulcerative colitis (UC). METHODS:
Ten patients with active UC received 30 g of GBF daily for
4 weeks in an open-label treatment protocol while the baseline
anti-inflammatory therapy was continued. The response to
treatment was evaluated clinically and endoscopically. Pre-
and post-treatment stool concentrations of short-chain fatty
acids were measured by gas-liquid chromatography. RESULTS:
Patients showed improvement in their clinical activity index
scores, with a significant decrease in the score from 6.9+/-1.4
to 2.8+/-1.5 (mean+/-S.E.M., P < 0.05). The endoscopic index
score fell from 6.1+/-2.3 to 3.8+/-2.3 (P < 0.0001). Patients
showed an increase in stool butyrate concentrations after
GBF treatment (P < 0.05). No side-effects were observed.
CONCLUSIONS: Oral GBF therapy may have a place in management
of ulcerative colitis, but controlled studies are needed
to demonstrate its efficacy in the treatment of this disorder.
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Nutrition Faculty, Texas A&M University,
College Station 77843-2471.
OBJECTIVE: To compare the effects
of adding barley bran flour and a barley oil extract to
a fat-modified diet on serum lipids in persons with hypercholesterolemia.
DESIGN: The basic design of the study was a randomized,
30-day intervention trial. It included a neutral-fiber control
group and a 1-week preintervention period for the collection
of baseline data. SUBJECTS: The subjects were 79 men and
women with hypercholesterolemia. Subjects had a mean age
of 48.2 years, and all completed the study. INTERVENTION:
All participants were instructed to follow the National
Cholesterol Education Program (NCEP) step 1 diet and were
randomly assigned to one of three treatment groups: 20 g
added cellulose, 3 g added barley oil extract, or 30 g added
barley bran flour. MAIN OUTCOME MEASURES: Total serum cholesterol,
high-density lipoprotein cholesterol (HDL-C), low-density
lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein
cholesterol were measured, along with serum triglycerides,
before the intervention, at week 1, at week 3, and at the
end of the intervention. STATISTICAL ANALYSES PERFORMED:
Student's paired t test was used to detect significant changes
within each treatment group from baseline to the end of
the 30-day intervention. In addition, Pearson's correlation
coefficients were used to detect significant correlations
between the variables measured. RESULTS: Addition of barley
bran flour significantly (P = .0001) decreased total serum
cholesterol (-0.60 mmol/L) as did addition of barley oil
(-0.50 mmol/L; P = .002) after 30 days of intervention.
Similarly, LDL-C decreased 6.5% with addition of barley
bran flour (P = .036) and 9.2% with addition of barley oil
(P = .003). Total serum cholesterol or LDL-C of the cellulose
control group did not decrease significantly over the same
period. HDL-C decreased significantly in the cellulose control
group and the barley bran flour group (-0.15 mmol/L, P =
.012, and -0.15 mmol/L, P = .006, respectively), but not
in the barley oil group. CONCLUSION: We conclude that addition
of barley bran flour or barley oil enhances the cholesterol-lowering
effect of the NCEP step 1 diet in individuals with hypercholesterolemia.
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MILLET |
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Department of Food Technology and Nutrition,
Faculty of Agricultural and Applied Biological Sciences,
Ghent University, Coupure Links 653, B-9000 Gent, Belgium.
Finger millet (Eleusine coracana),
kidney beans (Phaseolus vulgaris), peanuts (Arachis hypogoea),
and mango (Mangifera indica) were processed separately and
then combined, on the basis of their amino acid scores and
energy content, into a complementary food for children of
weaning age. The finger millet and kidney beans were processed
by germination, autoclaving, and lactic acid fermentation.
A mixture containing, on a dry matter basis, 65.2, 19.1,
8.0, and 7.7% of the processed finger millet, kidney beans,
peanuts, and mango, respectively, gave a composite protein
with an in vitro protein digestibility of 90.2% and an amino
acid chemical score of 0.84. This mixture had an energy
density of 16.3 kJ.g(-1) of dry matter and a decreased antinutrient
content and showed a measurable improvement in the in vitro
extractability for calcium, iron, and zinc. A 33% (w/v)
pap made from a mix of the processed ingredients had an
energy density of 5.4 kJ.g(-1) of pap, which is sufficient
to meet the energy requirements of well-nourished children
of 6-24 months of age at three servings a day and at the
FAO average breast-feeding frequency.
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BROWN RICE |
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Medical Research Council Toxicology
Unit, University of Leicester, United Kingdom.
Rice is a staple diet in Asia, where
the incidence of breast and colon cancer is markedly below
that in the Western world. We investigated potential colon
and breast tumor-suppressive properties of rice, testing
the hypothesis that rice contains phenols that interfere
with the proliferation or colony-forming ability of breast
or colon cells. Brown rice, its white milled counterpart,
and bran from brown rice were boiled and extracted with
ethyl acetate. The extracts were analyzed by high pressure
liquid chromatography-mass spectrometry. Eight phenols,
protocatechuic acid, p-coumaric acid, caffeic acid, ferulic
acid, sinapic acid, vanillic acid, methoxycinnamic acid,
and tricin, were identified in the extracts of bran and
intact brown rice. These extracts were separated into nine
fractions by column chromatography. The effect of bran extract
and its fractions at 100 microg/ml on cell viability and
colony-forming ability of human-derived breast and colon
cell lines was assessed. Bran extract decreased numbers
of viable MDA MB 468 and HBL 100 breast cells and colon-derived
SW 480 and human colonic epithelial cells as judged by the
3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4
-sulfophenyl)-2H-tetrazolium assay. It also reduced colony
formation of SW 480 colon and MDA MB 468 breast cells. Of
the eight phenols identified in the brown rice bran, when
applied at 50 microM, caffeic acid decreased numbers of
all cell types except HBL 100. Tricin, ferulic acid, and
methoxycinnamic acid interfered with cell viability in one
or more cell lines. Tricin (50 microM) and the other phenols
(200 microM) inhibited colony formation of SW 480 cells.
Clonogenicity of MDA MB 468 cells was inhibited by caffeic
acid, ferulic acid, and tricin (50 microM). Tricin was the
most potent anticlonogenic of the compounds with IC50s of
16 microM in the SW 480 colon cells and 0.6 microM in the
MDA MB 468 breast cells. The results suggest that: (a) brown
rice and bran contain compounds with putative cancer chemopreventive
properties; (b) certain phenols contained in brown rice
bran, e.g., tricin, may be associated with this activity;
and (c) these phenols are present at much lower levels in
white than in brown rice. Thus, the consumption of rice
bran or brown rice instead of milled white rice may be advantageous
with respect to cancer prevention.
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Department of Food and Nutrition, Faculity
of the Science of Living, Osaka City University, Japan.
The effect of brown rice with low
protein intake was studied in five healthy young men. Feces
were weighed, the digestibility of nutrients was determined,
and blood tests were made. Each subject followed a diet
consisting mainly of polished rice for 14 days and one consisting
mainly of brown rice for 8 days. Both diets contained 0.5
g protein per kg of body weight. The brown rice diet had
3 times as much dietary fiber as the polished rice diet.
On the brown rice diet, fecal weight increased, and apparent
digestibility of energy, protein, and fat decreased, as
did the absorption rates of Na, K, and P. The nitrogen balance
was negative on both diets, but more negative on the brown
rice diet. The phosphorus balance on the brown rice diet
was significantly negative, but other minerals were not
affected by the diet. The levels of cholesterol and minerals
in the plasma were not significantly different on the polished
rice diet and the brown rice diet. Comparing these results
with data on standard protein intake (Miyoshi, H. et al
(1986) J. Nutr. Sci. Vitaminol., 32, 581-589.), we concluded
that brown rice reduced protein digestibility and nitrogen
balance.
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WHEAT BRAN |
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Arizona Cancer Center and Nutritional
Sciences Interdisciplinary Program, University of Arizona,
Tucson 85716, USA.
BACKGROUND: The Wheat Bran Fiber (WBF)
trial was a double-blind, high-fiber versus low-fiber phase
III intervention trial in which participants were randomly
assigned to receive a cereal fiber supplement of either
2.0 g/day or 13.5 g/day to assess whether a high-fiber supplement
could decrease risk of recurrent colorectal adenomas. Although
no effect of the supplement on polyp recurrence was observed,
participants consumed a baseline average of 17.5 grams of
fiber per day, which may have been sufficient to protect
against adenoma recurrence. Therefore, we examined whether
baseline fiber intake affected colorectal adenoma recurrence
or modified the effect of treatment group in the WBF trial
participants. METHODS: Quartiles of baseline fiber intake
were calculated on the basis of the distribution in the
study population. Odds ratios (ORs) for adenoma recurrence
were calculated using the lowest quartile of fiber intake
as the reference. The effect of fiber from specific food
sources on adenoma recurrence was also assessed. All statistical
tests were two-sided. RESULTS: Adjusted ORs (95% confidence
intervals) for adenoma recurrence were 0.79 (0.56 to 1.12),
0.76 (0.54 to 1.08), and 0.83 (0.57 to 1.19) for the second,
third, and fourth quartiles, respectively. Fiber from the
three primary food sources (fruits; breads, cereals and
crackers; and vegetables) had no appreciable effect on adenoma
recurrence. Baseline fiber intake also had little effect
on adenoma recurrence when the population was stratified
by treatment group. In addition, there was no interaction
between treatment group and quartile of baseline fiber intake.
CONCLUSIONS: No association was found between amount of
fiber consumed at baseline and adenoma recurrence in the
WBF trial participants. The baseline fiber intake, whether
considered as a whole or from specific sources, did not
modify the effect of treatment group.
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Clinical Nutrition and Risk Factor
Modification Center, St. Michael's Hospital, Toronto, Ontario,
Canada.
OBJECTIVE: Cohort studies indicate
that cereal fiber reduces the risk of diabetes and coronary
heart disease (CHD). Therefore, we assessed the effect of
wheat bran on glycemic control and CHD risk factors in type
2 diabetes. RESEARCH DESIGN AND METHODS: A total of 23 subjects
with type 2 diabetes (16 men and 7 postmenopausal women)
completed two 3-month phases of a randomized crossover study.
In the test phase, bread and breakfast cereals were provided
as products high in cereal fiber (19 g/day additional cereal
fiber). In the control phase, supplements were low in fiber
(4 g/day additional cereal fiber). RESULTS: Between the
test and control treatments, no differences were seen in
body weight, fasting blood glucose, HbA(1c), serum lipids,
apolipoproteins, blood pressure, serum uric acid, clotting
factors, homocysteine, C-reactive protein, magnesium, calcium,
iron, or ferritin. LDL oxidation in the test phase was higher
than that seen in the control phase (12.1 +/- 5.4%, P <
0.034). Of the subjects originally recruited, more dropped
out of the study for health and food preference reasons
from the control phase (16 subjects) than the test phase
(11 subjects). CONCLUSIONS: High-fiber cereal foods did
not improve conventional markers of glycemic control or
risk factors for CHD in type 2 diabetes over 3 months. Possibly
longer studies are required to demonstrate the benefits
of cereal fiber. Alternatively, cereal fiber in the diet
may be a marker for another component of whole grains that
imparts health advantages or a healthy lifestyle.
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Auckland Cancer Society Research Centre,
Faculty of Medicine and Health Science, The University of
Auckland, Private Bag 92019, 1000, Auckland, New Zealand.
Diets containing wheat bran (WB) protect
against cancers of the colon or breast in rats, and may
be beneficial in humans. In a previous study of rats treated
with the carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline
(IQ), inclusion of 10% wheat bran in the diet led to an
apparent reduction in IQ metabolites but not of intact IQ
in plasma. In the present study, male Wistar rats were fed
diets containing 0, 10 or 20% wheat bran, and effects on
xenobiotic metabolising enzymes compared. Wheat bran-supplementation
showed differential effects on phase I enzymes, significantly
increasing the activity of hepatic cytochrome P450 isozyme
CYP3A2, but slightly reducing the activity of CYP1A1/2.
The activities of both hepatic phase II detoxification enzymes
glutathione-S-transferase and glucuronosyl transferase were
also reduced. Western blotting revealed similar effects
on _expression of the proteins. Interestingly, the _expression
of xenobiotic metabolising enzymes (XME) in the colon appeared
to be modulated independently of hepatic XME. Although the
wheat bran-supplemented diet still led to an increased _expression
of CYP3A, it now slightly increased CYP1A in the colon.
However, 20% wheat bran significantly increased the _expression
of both glutathione transferase isozymes, GST A1 & A2, in
the colon. Natures Gold (NG) is a commercial wheat bran
derivative which is lower than wheat bran in dietary fibre,
but enriched in vitamins, minerals and various phytochemicals.
Dietary supplementation with 20% Natures Gold led to similar
trends as seen in wheat bran-fed rats, but more potent effects
in both hepatic and colonic enzymes. The significance of
these changes for activation of carcinogens to mutagenic
metabolites was investigated using the Salmonella/mammalian
microsome mutagenicity test. The activation of IQ and benzo[a]pyrene,
but not cyclophosphamide, to a mutagen by hepatic S9 from
wheat bran-fed or Natures Gold-fed rats was significantly
reduced compared with S9 from animals on a diet lacking
wheat bran. We suggest that modulation of xenobiotic metabolising
enzymes may be an important component of cancer protection
by wheat bran, and this effect may relate to micronutrients
or cancer-protective non-nutrient phytochemicals rather
more than to dietary fibre.
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Nutritional Carcinogenesis and Chemoprevention
Program, American Health Foundation, Valhalla, New York
10595, USA.
Epidemiological studies suggest an
inverse relationship between the intake of dietary fiber,
particularly fiber from cereal grains, and colon cancer
risk. Animal model assays have demonstrated that the protective
effects of dietary fiber on colon cancer development depend
on the nature and source of the fiber. Wheat bran (WB) appears
to inhibit colon tumorigenesis more consistently than do
oat bran or corn bran. This study was designed to determine
whether specific WB fractions such as WB fiber, WB lipids,
or phytic acid differentially affect colon carcinogenesis
in a well-established colon cancer model. In addition, the
modulating effect of specific fractions of WB on the activities
of inducible nitric oxide synthase (iNOS) and cyclooxygenase
(COX)-1 and COX-2 enzymes were assessed in colon tumors
as those have been shown to play a role in tumor progression.
At 5 weeks of age, groups of male F344 rats were assigned
to one of six diets: a high-fat diet containing 10% WB (control
diet) and experimental high-fat diets containing 10% dephytinized
WB (WB-P), 10% defatted WB (WB-F), 10% dephytinized and
defatted WB (WB-PF), 10% WB-PF fortified with 2% bran oil
and/or with 0.4% phytate. At 7 weeks of age, all eats except
those in the vehicle-treated groups were given two weekly
s.c. injections of azoxymethane (AOM) at a dose rate of
15 mg/kg body weight/week. They continued to receive their
respective diets until 50 weeks after carcinogen treatment
and were then killed. Colon tumors were analyzed for iNOS,
COX-1, and COX-2 _expression and enzymatic activities. Colon
tumors were evaluated histopathologically and classified
as adenomas and adenocarcinomas. We found that removal of
phytic acid (WB-P) or lipids (WB-F) from WB had no significant
effect on colon tumor incidence (% animals with tumors)
or multiplicity (tumors/ animal), whereas removal of both
phytate and lipids from WB (WB-PF) significantly increased
colon tumor multiplicity and volume. Interestingly, WB-PF
fortified with excess bran oil or with bran oil plus phytate
significantly inhibited colon tumor incidence, multiplicity,
and volume; but supplementation of WB-PF with phytate alone
had no significant effect on colon tumorigenesis in rats
suggesting that lipid fraction of WB possesses tumor-inhibitory
properties. Moreover, feeding WB-PF diet significantly increased
iNOS, total COX and COX-2 enzyme activities, and iNOS protein
_expression in colon tumors as compared with wheat bran
control diet. Feeding the WB-PF that was fortified with
excess bran oil alone or with bran oil plus phytate significantly
suppressed the activities of iNOS and COX-2 as well as the
_expression of iNOS and COX-2 in colon tumors compared with
that in rats fed the WB diet or WB-PF diet. The study demonstrates
for the first time that the lipid fraction of wheat bran
has strong colon tumor inhibitor properties. The exact mechanism(s)
by which the lipid fraction of WB inhibits colon carcinogenesis
in addition to alteration of iNOS and COX activities remains
to be elucidated. Additional studies are warranted to identify
biologically active constituents of lipid fraction of WB
and their relative role in colon tumor inhibition.
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Department of Medicine and the Arizona
Cancer Center, University of Arizona Health Sciences Center,
Tucson 85724, USA.
The effects of wheat bran fiber on
surrogate endpoint biomarkers for colon cancer risk have
been studied in rats and humans. In both species, there
is little evidence that wheat bran fiber significantly modifies
epithelial cell proliferation. In rat studies, however,
dietary supplementation with wheat bran fiber has decreased
mucosal formation of aberrant crypt foci, an important marker
currently used to estimate the efficacy of colon cancer
chemoprevention agents. In humans, wheat bran fiber has
been shown to consistently decrease fecal bile acid concentrations,
mainly by reducing toxic secondary bile acids.
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Cattedra di Gastroenterologia I, Universita
La Sapienza, Rome, Italy.
After a two-week basal period, 24
patients were randomly allocated to receive, with a crossover
double-blind design, for two consecutive four-week periods,
bran (20 g/24 hr) or placebo. The daily intake of water
and dietary fibers was standardized. Symptomatology, oroanal
transit time, bowel frequency, and stool weight were assessed
in basal conditions and at week 4 and 8 of the treatment.
Oroanal transit time decreased and bowel frequency and stool
weight increased significantly during both bran and placebo
administration in comparison with basal period. Bran treatment
was more effective than placebo in improving bowel frequency
and oroanal transit. During bran treatment oroanal transit
time became normal only in patients with slow colonic transit
and not in those with slow rectal transit. Neither the occurrence
nor the severity of the most frequent accompanying symptoms
of chronic constipation differed significantly between placebo
and bran treatments.
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WHEAT FLOUR |
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Sylvester Comprehensive Cancer Center,
University of Miami, School of Medicine, FL 33101.
In order to identify factors that
may explain the great variation in mortality from esophageal
cancer in Shanxi Province, China, an ecological study was
carried out in 21 communes in that province. Mortality data
were obtained from the registration records of the population
of 148,928 during 1983 to 1988, which provided 744,640 person-years
of observation. The data regarding average consumption of
each kind of grain, potatoes and sweet potatoes were from
food allocation records. The data regarding consumption
of meat, eggs, fruit, vegetables and the data regarding
alcohol drinking were from interviews. The concentrations
of nitrite and of nitrate in pickled vegetables and in drinking
water were measured. A significant positive relation was
found between mortality rate and the consumption of dietary
corn and wheat flour. Also, a significant inverse relation
was found between the mortality rate and the dietary sorghum
and millet level. The age- and sex-adjusted mortality-rate
ratio of esophageal cancer for residents in the third and
highest quartiles of corn- and wheat-flour consumption are
1.4 (95% CI: 1.1-2.0) and 3.2 (2.5-4.2), respectively, compared
with those in the lowest quartile. Other factors studied
did not contribute to the great variation in esophageal
cancer mortality in the areas studied.
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WHEAT GERM |
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Center for the Study of Host Resistance,
McGill University, Montreal, Quebec, Canada.
The protozoan parasite Giardia lamblia
is a major cause of waterborne enteric disease worldwide.
Lectins are proteins that bind to carbohydrate (sugar) moieties.
Potential targets for lectins are found on the surface of
most single-celled organisms. Modest concentrations of wheat
germ agglutinin (WGA) have been shown to inhibit G. lamblia
excystation and trophozoite growth in vitro and can reduce
cyst passage in mice infected with the closely related protozoan
parasite, G. muris. Commercial preparations of wheat germ
(WG) contain 13-53 microg of WGA per gram. We performed
a double-masked, placebo-controlled study of dietary supplementation
with WG in 63 subjects with giardiasis in Montreal and Lima
(25 asymptomatic patients passing cysts; 38 patients with
symptoms). Asymptomatic subjects received WG (2 g, 3 times
a day) or placebo (cornstarch, 2 g, 3 times a day) for 10
days, followed by metronidazole (250 mg 3 times a day) for
7 days. Symptomatic subjects received metronidazole (250
mg 3 times a day) plus either WG or placebo for 7 days.
Stool specimens were collected every day (Montreal) or every
other day (Lima) for 10 days and on Day 35 for microscopic
examination and coproantigen determination. Subjects kept
a diary of symptoms for 10 days after recruitment. In asymptomatic
subjects, both cyst passage and coproantigen levels were
reduced by approximately 50% in those taking WG compared
with the placebo group (P < 0.01 and P = 0.06, respectively).
In symptomatic subjects, cyst passage and coproantigen levels
fell precipitously in response to metronidazole therapy,
and there were no clinically important differences between
those receiving supplemental WG or placebo. However, symptoms
appear to have resolved more rapidly in the subjects taking
WG in addition to metronidazole. The WG supplement was well
tolerated in both symptomatic and asymptomatic subjects.
These data suggest that components of WG, possibly WGA,
either alone or in combination with antiprotozoal agents,
can influence the course of human giardiasi.
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UCLA School of Medicine, Harbor-UCLA
Research and Education Institute, Torrance, California 90502,
USA.
The fermented wheat germ extract with
standardized benzoquinone composition has potent tumor propagation
inhibitory properties. The authors show that this extract
induces profound metabolic changes in cultured MIA pancreatic
adenocarcinoma cells when the [1,2-13C2]glucose isotope
is used as the single tracer with biologic gas chromatography-mass
spectrometry. MIA cells treated with 0.1, 1, and 10 mg/mL
wheat germ extract showed a dose-dependent decrease in cell
glucose consumption. uptake of isotope into ribosomal RNA
(2.4%, 9.4%, and 28.0%), and release of 13CO2. Conversely,
direct glucose oxidation and ribose recycling in the pentose
cycle showed a dose-dependent increase of 1.2%, 20.7%, and
93.4%. The newly synthesized fraction of cell palmitate
and the 13C enrichment of acetyl units were also significantly
increased with all doses of wheat germ extract. The fermented
wheat germ extract controls tumor propagation primarily
by regulating glucose carbon redistribution between cell
proliferation-related and cell differentiation-related macromolecules.
Wheat germ extract treatment is likely associated with the
phosphorylation and transcriptional regulation of metabolic
enzymes that are involved in glucose carbon redistribution
between cell proliferation-related structural and functional
macromolecules (RNA, DNA) and the direct oxidative degradation
of glucose, which have devastating consequences for the
proliferation and survival of pancreatic adenocarcinoma
cells in culture.
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Unite de recherche sur le transport
des lipides, Unite 130, INSERM (National Institute of Health
and Medical Research), Marseille, France.
In previous short-term studies in
rats and humans, the ingestion of raw wheat germ lowered
plasma triglycerides and cholesterol. Thus, the present
study was designed to investigate the possible long-term
effects of wheat germ intake. Diet supplementation with
raw wheat germ or partially defatted wheat germ was tested
in two separate groups of 10 and 9 free-living human subjects,
respectively. They all exhibited hypercholesterolemia (6.14-9.67
mmol/L cholesterol) and 11 had hypertriglyceridemia. None
was diabetic. Fasting blood samples were taken at the beginning
of the study, after 4 wk of 20 g/d wheat germ intake, after
14 additional weeks of 30 g/d wheat germ intake and after
12 wk without any supplementation. Dietary records were
kept for seven and three consecutive days, before and during
the wheat germ intake periods, respectively. Raw wheat germ
intake significantly decreased plasma cholesterol (-8.7%)
and tended to reduce VLDL cholesterol (-19.6%) after 4 wk.
After 14 additional weeks, plasma cholesterol (-7.2%) and
LDL cholesterol (-15.4%) remained lower and plasma triglycerides
(-11.3%) tended to be lower. The apo B:apo A1 ratio significantly
decreased after both periods. Partially defatted wheat germ
transiently decreased plasma triglycerides and cholesterol
after a 4-wk intake. The present data indicate that wheat
germ reduces cholesterolemia in the long term and could
play a beneficial role in the dietary management of type
IIa and IIb hyperlipidemia.
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Wheat germ lectin (WGL) induced proliferation
of T-lymphocyte colony-forming units (TL-CFU) from human
peripheral blood mononuclear cells (PBMC) in a one stage
agar culture needing higher cell numbers than phytohaemagglutinin
(PHA). However, WGL preactivated TL-CFU in a first stage
liquid culture for the growth of PHA-dependent T-lymphocyte
colonies in a subsequent agar culture. These results suggested
that WGL and PHA have biological activities in common. WGL
and PHA both induced the _expression of Interleukin 2 (IL-2)
receptors by PBMC to become responsive to IL-2, although
production of IL-2 by WGL-stimulated PBMC was low compared
with PHA-stimulated PBMC. This might account for the low
proliferative response of PBMC to WGL.
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WHITE RICE |
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The objective of this study was to
analyze aspects of the metabolism and bio-availability of
fluoride after consumption of a sample of polished white
rice containing 5.6 ppm fluoride ion. Up to 400 g of fluoridated
rice was consumed by three volunteer adult subjects over
specific time periods on two separate occasions. Saliva
concentrations were elevated immediately and remained so
90 minutes following ingestion, among other indications.
It was concluded that polished rice has the potential to
be a useful vehicle for dietary fluoride transport.
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Advanced Medical Research, 8251 Raymond
Road, Madison, WI 53719, USA.
Tocotrienols are effective in lowering
serum total and LDL-cholesterol levels by inhibiting the
hepatic enzymic activity of beta-hydroxy-beta-methylglutaryl
coenzymeA (HMG-CoA) reductase through the post-transcriptional
mechanism. alpha-Tocopherol, however, has an opposite effect
(induces) on this enzyme activity. Since tocotrienols are
also converted to tocopherols in vivo, it is necessary not
to exceed a certain dose, as this would be counter-productive.
The present study demonstrates the effects of various doses
of a tocotrienol-rich fraction (TRF25) of stabilized and
heated rice bran in hypercholesterolemic human subjects
on serum lipid parameters. Ninety (18/group) hypercholesterolemic
human subjects participated in this study, which comprised
three phases of 35 days each. The subjects were initially
placed on the American Heart Association (AHA) Step-1 diet
and the effects noted. They were then administered 25, 50,
100, and 200 mg/day of TRF25 while on the restricted (AHA)
diet. The results show that a dose of 100 mg/day of TRF25
produce maximum decreases of 20, 25, 14 (P<0.05) and 12%,
respectively, in serum total cholesterol, LDL-cholesterol,
apolipoprotein B and triglycerides compared with the baseline
values, suggesting that a dose of 100 mg/day TRF25 plus
AHA Step-1 diet may be the optimal dose for controlling
the risk of coronary heart disease in hypercholesterolemic
human subjects.
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Department of Pathology, Gifu University
School of Medicine, Japan.
Polyphenolic compound chlorogenic
acid (CGA) known to be much contained in coffee beans was
found to have a regressive effect on induced aberrant crypt
foci (ACF) as well as on development of ACF in azoxymethane
(AOM)-induced colorectal carcinogenesis in rats. Rice germ
and gamma-aminobutyric acid-enriched defatted rice germ
inhibited AOM-induced ACF formation and colorectal carcinogenesis
in rats. Ferulic acid (FA) also known to be contained in
coffee beans and rice prevented AOM-induced ACF formation
and intestinal carcinogenesis in rats. Both of food factors,
coffee and rice may be of benefit to prevention of human
colorectal cancers.
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Department of Dermatology, Yokohama
City University Medical Center, Yokohama, Japan.
A 30-year-old man with atopic dermatitis
had had erythema and itching of the hands after washing
rice in water, though he had always eaten cooked rice without
problems. Handling test with water used to wash regular
rice was performed on abraded hands, and produced urticarial
erythema after several minutes. Applications of water used
to wash allergen-reduced rice were negative for urticarial
reaction. Prick test with water used to wash regular rice
was +++. However prick test reaction with water used to
wash allergen-reduced rice was +. Histamine-release test
of regular rice-washing water was grade 3 and that of allergen-reduced
rice grade 1. In immunoblotting analysis with regular rice
washing water, there were no bands with this patient. These
results suggest that the allergen responsible for contact
urticaria in this patient might be water-soluble, heat-unstable,
and not contained in allergen-reduced rice.
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Department of Nephrology, Kameda Medical
Center, Chiba, Japan.
Diet therapy for patients with chronic
renal failure is based on low protein and high energy. To
achieve strict diet therapy, it is necessary to use specially
formulated low protein foods. Previously, rice with a low
content of protein was not available, but recently, a low
protein rice (LGC-1: low glutelin content-1) has been developed.
LGC-1 was found to have a low content of glutelin in its
seed protein compared to other ordinary rice. Glutelin is
the major digestive protein in the rice grain. We studied
the usefulness of LGC-1 in the diet therapy of patients
with chronic renal failure. Twenty-three patients were placed
on the low protein diet (0.6-0.9 g/kg/day) during the pre-study
period (a mean of 10 months). Subsequently they were followed
with the same diet using LGC-1 for the staple foods during
the study period (mean of 7 months). Protein intake and
the slope of the reciprocal of serum creatinine did not
differ between each study period in all patients. Among
the 23 patients, 9 consumed rice mainly as the staple food
(120-180 g/day as polished rice: rice group), according
to the results of a questionnaire. In the rice group, protein
intake decreased (from 47 +/- 9 to 42 +/- 9 g/day, p < 0.05),
and the slope of the reciprocal of serum creatinine reduced
(from -4.59 +/- 4.33 to -1.47 +/- 3.51
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