Food-Based Ingredients to Modulate Blood Glucose - Advances in Food and Nutrition Research - page 210

diabetes subjects ( Hosoda et al., 2003 ), but the authors were not able to
explain the effect completely. In healthy subjects, 1 g instant black tea reduced
the blood glucose response to 75 g glucose but increased the insulin response
( Bryans, Judd, & Ellis, 2007 ) . An 8-week trial in Japan with green tea extract
resulted in a significant reduction in the HbA1c levels of adults who had bor-
derline diabetes ( Fukino et al., 2008 ). Another study looking at the dose and
frequency of green tea consumption in healthy subjects showed reduced
fasting blood glucose and fructosamine levels in those consuming 3% green
tea against those who consumed 1% concentration of green tea
( Maruyama, Iso, Sasaki, & Fukino, 2009 ) . There was no effect noted for fre-
quency of green tea consumption on any of the blood glucose parameters.
However, not all studies have shown a beneficial effect of green tea.
A 300-ml green tea with breakfast consisting of white bread and turkey did
not show any effect on glucose or insulin levels in healthy subjects ( Josic,
Olsson, Wickeberg, Lindstedt, & Hlebowicz, 2010 ). In type 2 diabetes
patients also, no effect of 9 g green tea consumption for 4 weeks was noticed
on glucose concentration, insulin concentration, or insulin resistance.
Table 5.6 gives a summary of studies carried out using spice-based ingredients
for normal levels blood glucose and insulin management.
9. LEGUME-BASED INGREDIENTS
Legumes are also important food groups that are known to reduce
postprandial glycemic response. Many factors are responsible for this such
as their rigid cotyledon walls, less susceptibility of their starch to enzyme
digestion, high levels of nondigestible carbohydrates such as resistant starch,
oligosaccharides, nonstarch polysaccharides and protein, and also the pres-
ence of a -amylase inhibitors and other polyphenols in the legumes
( Bj¨ rck, Liljeberg, and ¨ stman, 2000a ). Goni and Valentı´n-Gamazo
(2003) prepared spaghetti with chick pea flour (25%) and compared it with
wheat spaghetti and white bread in healthy female subjects. They noticed a
significant reduction of 14 units in the GI of the chick pea flour spaghetti
compared to the wheat pasta. Pasta itself is a food product showing reduced
glycemic response compared to other starchy foods. Different pasta products
such as spaghetti, macaroni, spaghetti porridge, and bread made of spaghetti
ingredients were compared with mashed potatoes in a study using healthy
subjects ( Granfeldt & Bj¨ rck, 1991 ). The authors noticed lowGI for the spa-
ghetti products compared to the bread and potatoes due to the compact
structure of the pasta products that restrict the enzyme access to the starch.