Fruit-
en sojayoghurt tegen diabetes.*
Fruityoghurts en yoghurts op basis van soja kunnen een belangrijke rol spelen bij de bestrijding van diabetes-2 en hoge bloeddruk volgens een Amerikaans onderzoek.
Medicijnen ter bestrijding van pieken in bloedsuikerwaarden richten zich vaak op twee enzymen, alfa amylase en alfa glucosidase, die verantwoordelijk zijn voor de omzetting van koolhydraten, waardoor deze in de darmen opgenomen kunnen worden. Door deze twee enzymen te blokkeren wordt de opname van suikers vertraagd. Vaak is bij diabetes patiënten ook sprake van hoge bloeddruk en veel medicatie daarvoor blokkeert het ACE-1 enzym, een enzym dat verantwoordelijk is voor samentrekking van de bloedvaten. Al deze medicijnen hebben echter vaak nare bijwerkingen.
In dit onderzoek werd nu gekeken of (fruit)yoghurt effect kan hebben op deze drie enzymen. Daarvoor werden voor de testen in de supermarkt diverse soorten yoghurt, natuur, met perzik, aardbei en bosbessen en soja-yoghurt, puur en met fruit, gekocht.
De resultaten van het onderzoek zijn dat alle fruityoghurts en de sojayoghurt in staat zijn zowel het alfa amylase als het alfa glucosidase enzym te blokkeren. Vooral de sojayoghurts, zowel natuur als die met bosbessen deden daarenboven ook nog het ACE-1 enzym blokkeren. De gewone fruityoghurts deden dat duidelijk minder. De gemeten hoeveelheden bioactieve stoffen waren duidelijk het hoogst in de sojayoghurts. Zelfs in de soja natuuryoghurt was hoger als de gewone fruityoghurts,. De sojayoghurt met bosbessen had veruit de meeste bioactieve stoffen.
Fruit
Yogurt Could Play An Important Role In Diabetes Management
Yogurt
enriched with fruit or made from soy could play an important dietary role for
people living with Type 2 diabetes and high blood pressure, suggests new
findings by University of Massachusetts Amherst researchers.
Led by Kalidas Shetty, the UMass Amherst scientists screened extracts from a
sampling of dairy and soy yogurts for properties that could help keep diabetes
and hypertension in check, such as the activity level of enzymes that help
moderate blood glucose levels. The researchers found that fruit-enriched
yogurts-especially those made with blueberries or made from soy-contain active
natural compounds that may curb some aspects of diabetes, the researchers report
in an upcoming issue of the Journal of Food Biochemistry.
The findings provide a strong rationale for further clinical studies, and for
incorporating "healthy diet design" into disease management strategies,
says Shetty. "What one eats should be part of an overall approach to
therapy," he says.
Doctoral students Emmanouil Apostolidis and Young-In Kwon collaborated with
Shetty on the research.
Type 2 diabetes, which accounts for roughly 90 percent of U.S. cases, is often
associated with obesity, high blood pressure and elevated levels of cholesterol.
The disease is characterized by an abnormal rise in blood sugar right after a
meal. This chronic high blood sugar, known as hyperglycemia, is associated with
many of the complications that can arise from the disease, including the failure
of various organs such as the kidneys, heart, eyes and problems with nerves and
blood vessels.
Medications that prevent the spike in blood glucose often target certain
enzymes-in particular, enzymes that are responsible for modifying carbohydrates
before they can be absorbed by the small intestine. Carbohydrates are the major
source of blood sugar and inhibiting these carb-altering enzymes-alpha-amylase
and alpha-glucosidase-slows the body's absorption of sugars.
The researchers were also interested in a third enzyme-angiotensin-I converting
enzyme or ACE-I-which plays a role in the constriction of blood vessels.
Medications known as ACE inhibitors block the activity of this enzyme, and such
medications are used in treating high blood pressure in both diabetic and
non-diabetic patients.
Such medications have been shown to be an effective strategy for diabetes
management, yet they can have unwanted side effects, says Shetty. Previous
research by Shetty and others found that certain plant compounds also play a
role in blocking all three of these enzymes, opening up the possibility that
foods rich in such compounds may provide health benefits, but without the
adverse side affects, he says.
So Shetty and his team went to the local supermarket and bought peach,
strawberry, blueberry and plain yogurts made by four different brands, including
a soy brand. The researchers took samples of each yogurt, and tested their
ability to inhibit each of the enzymes of interest, using water or a buffer
solution as a control.
Of all the sampled yogurts, soy yogurt enriched with blueberries packed the most
punch, inhibiting the activity of all three enzymes tested, the researchers
report. Peach and strawberry enriched yogurts also fared well in their ability
to inhibit the carb-altering enzymes alpha-amylase and alpha-glucosidase.
The researchers also tested the yogurts for antioxidant activity and the
quantity of a group of plant chemicals known as phenols. Phenols and polyphenols
are found in a wide variety of plants; they give red wine and tea their
heart-healthy boosts and are especially prominent in dark-colored fruits and
vegetables. The benefits of these compounds seem to come from their antioxidant
powers-polyphenols scavenge cells for nasty free radicals such as reactive forms
of oxygen. Free radicals can damage cellular machinery much the way that metal
is turned to rust.
The extracts from blueberry yogurts had the second-highest concentrations of
phenols and the most antioxidant activity, the researchers found, beat out only
by soy (even the plain soy yogurt had higher phenol content than any regular
yogurt with fruit). The blueberry extracts also were the best at blocking the
action of alpha-glucosidase, which was correlated with the amount of phenols.
There was much more variation in which extracts inhibited alpha-amylase and
ACE-I, and it wasn't necessarily correlated with phenol content says Shetty. Soy
yogurts had the highest phenol content overall, and were the best at inhibiting
ACE-I.
A growing body of research indicates that diets rich in fruits and vegetables
are associated with lower incidences of certain diseases, and plant compounds
such as phenols are of increasing interest to scientists, says Shetty. How these
dietary antioxidants mediate disease isn't clearly understood, Shetty suspects
that they stimulate the body's own antioxidant enzymes to shift into a defense
mode that protects tissues from chronic disease, many of which are associated
with damaging free radicals.
"The numbers of people with environment-related diseases are going through
the roof," says Shetty, noting that in the United States alone more than 20
million people are estimated to have diabetes. Worldwide estimates are that 170
million to 200 million people have diet-linked Type 2 diabetes, and the World
Health Organization expects those numbers to double by the year 2030.
"Poor communities and especially Native Americans are afflicted with Type 2
diabetes more than other communities," say Shetty. "Cost-effective
dietary changes are essential for fighting this disease, and traditional diets
that have a higher content of these protective antioxidants are an important
part of the solution. We should be able to use diet along with other therapies,
and diabetes is a disease where this especially makes sense."
University of Massachusetts Amherst
200 Munson Hall
Amherst, MA 01003
United States (Nov.
2006) (Opm. Zo zie je maar dat vaak
bij de juiste voeding geen medicijnen, en hun bijwerkingen nodig zijn.)