Edited from "Cholesterol-lowering
effects of oat β- glucan. RA Othman, MH Moghadasian, PJ Jones. Nutr Rev. 2011 Jun; 69(6):299-309."
Oat β-glucan, a soluble dietary fiber found in the endosperm
cell walls of oats, has cholesterol-lowering properties. The United States Food and Drug Administration
(FDA) approved a health claim for β-glucan soluble fiber from oats for reducing
plasma cholesterol levels and risk of heart disease in 1997. In 2004
the United Kingdom Joint Health Claims Initiative (JHCI) allowed a
cholesterol-lowering health claim for oat β-glucan.
Results of our analysis show that
studies during the past 13 years support the suggestion that intake
of oat β-glucan at daily doses of at least 3g may reduce plasma total and
low-density lipoprotein (LDL) cholesterol levels by 5-10% in
normocholesterolemic or hypercholesterolemic subjects.
Studies described herein
have shown that, on average, oat consumption is associated with 5% and 7%
reductions in total and LDL cholesterol levels, respectively.
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Hypoglycemic effects and biochemical mechanisms of oat products on streptozotocin-induced diabetic mice.SourceSchool
of Food and Biological Engineering, Zhengzhou University of Light
Industry, Zhengzhou, Henan, China. shenruiling2002@yahoo.com.cn AbstractOat
products are abundant in β-glucan, which could lower the glycemic index
of products or foods. A low glycemic index is beneficial in the control
of postprandial glycemia. The study examined the hypoglycemic effects
of oat products that had the same percentage of oat β-glucan and were
added into the diet fed to streptozotocin-induced diabetic mice for 6
weeks, and potential mechanisms are discussed here. Oat products
significantly decreased fasting blood glucose and glycosylated serum
protein (p < 0.05), but the hypoglycemic effect was not more than
that of metformin (p > 0.05). Oat products increased glycogen,
hormone, and nuclear receptor levels (p < 0.05), decreased free fatty
acid content and succinate dehydrogenase activity (p < 0.05), and
inhibited pancreatic apoptosis (p < 0.05). The results showed oat
products had hypoglycemic effects. Hypoglycemic effects of oat products
might be regulating glucose and fat metabolisms, stimulating hormone
secretion, activating the nuclear receptor, and protecting organ
function.
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Glycemic responses of oat bran products in type 2 diabetic patients.
Cereal
products with low postprandial glycemic response are encouraged in the
management of hyperglycemia. In this study, we determined the
postprandial glycemic response of two different oat bran products in
patients with type 2 diabetes. We also investigated the effects of oat bran flour on postprandial glucose response following an oral glucose load.
METHODS AND RESULTS: A
randomized, controlled, repeated measures design with two test series
was used. Twelve type 2 diabetic patients participated in five 2-h meal
glucose tolerance tests on separate occasions. Volunteers were given in
random order oat bran flour, oat bran crisp and glucose load providing
12.5 g glycemic carbohydrate (series 1), 25 g glucose load alone and 25 g
glucose load with 30 g oat bran flour (series 2). Finger-prick
capillary blood analysis was carried out fasting and then 15, 30, 45,
60, 90 and 120 min after the start of the meal.
The oat bran flour had a
lower 0-120 min area under the glucose response curve (AUC) (47+/-45
mmol min/L) than the glucose load (118+/-40 mmol min/L) (p<0.002),
but there was no difference between the oat bran crisp (93+/-41 mmol
min/L) and the glucose load in this respect.
The oat bran flour
decreased the glucose excursion from baseline by 1.6 mmol/l (2.4, 0.8)
(mean (95% CI)) and 1.5 mmol/l (2.0, 1.1) at 30 and 45 min after the
glucose load, respectively.
CONCLUSIONS: Oat bran flour
high in beta-glucan had a low glycemic response and acted as an active
ingredient decreasing postprandial glycemic response of an oral glucose
load in subjects with type 2 diabetes.
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The effect of beta-glucan on the glycemic and insulin index.SourceFunctional Foods Forum, University of Turku, Helsinki, Finland.
OBJECTIVE: To
determine the effects of oat products with increasing beta-glucan
content on the glycemic (GI) and insulin indexes (II) of oat products,
and to establish the effect of physical properties of beta-glucan on
these physiological responses. DESIGN: Test group (n=10) randomly attended to three glucose tolerance tests and glycemic response tests for four oat bran products. SETTINGS: Functional
Foods Forum and the Department of Food Chemistry, University of Turku,
and the Department of Food Technology, University of Helsinki. SUBJECTS: One male and nine female volunteers were recruited from university students and staff, and all completed the study. INTERVENTIONS: GI
and II of different products were calculated for each subject using the
average of parallel glucose tolerance tests and the subsequent
glycemic/insulinemic responses for each product. Average indexes for
products were calculated according to the individual data. RESULTS: The
glycemic responses to oat products with increasing amounts of
beta-glucan had lower peak values than the reference glucose load. The
amount of extractable beta-glucan had a high correlation between the
glycemic and insulinemic response. CONCLUSION: In
addition to the total amount of beta-glucan in oat products, the amount
of extractable beta-glucan in oat products explains the magnitude of the
decrease in glycemic responses to carbohydrate products.
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