YOGHURT – ITS INSULINEMIC INDEX IS HIGHER THAN ITS GI
Numerous
studies over the past 20 years have shown that high yoghurt intake is
associated with a reduced risk of type 2 diabetes. In Nutrition Today,
Prof Tom Wolever talks about yoghurt’s glycemic and insulinemic impact
of yoghurt.
“There is evidence that low GI and low GL (glycemic load) diets
are associated with a reduced risk of type 2 diabetes. The 93 GI values
for yoghurt in the University of Sydney’s GI database have an average of
34 and most (9 out of 10) of the yoghurts are low GI. The 43 plain
yoghurts in the database have a lower GI (average GI = 27) than the 50
sweetened yoghurts (average GI = 41). This difference is not explained
by sugar, per se, but rather by the higher protein-to-carbohydrate ratio
in plain yoghurt. Although yoghurt has a low GI, its insulinemic index
is higher than its GI. High insulin responses may be deleterious because
hyperinsulinemia is associated with an increased risk of type 2
diabetes. Nevertheless, this may not be a concern for yoghurt because,
although its insulinemic index is higher than its GI, the insulinemic
index of yoghurt is within the range of insulinemic index values for
non-dairy low-GI foods. In addition, mixed meals containing dairy
protein elicit insulin responses similar to those elicited by mixed
meals of similar composition containing non-dairy protein. Because the
GI of yoghurt is lower than that of most other carbohydrate foods,
exchanging yoghurt for other protein and carbohydrate sources can reduce
the GI and GL of the diet, and is in line with recommended dietary
patterns, which include whole grains, fruits, vegetables, nuts, legumes,
fish, vegetable oils, and yoghurt.”
What’s the Insulinemic Index? Prof
Jennie Brand-Miller explains. “One of insulin’s many functions is to
act as a growth hormone designed to drive nutrients into cells – not
just glucose but also amino acids, the building blocks of new tissue.
When we eat carb-rich foods our blood glucose levels rise and our
pancreas then releases insulin (a hormone) that drives the glucose out
of our bloodstream and into our body’s cells where our body can use it
as an immediate source of energy or store it as glycogen. What many
people don’t realise is that protein foods (meat, fish, eggs and dairy
foods) also stimulate insulin secretion – that’s why you may see them
described as insulinogenic.”
Scientists at the
University of Sydney have been researching the food insulin index or FII
for more than 20 years. “The FII looks at how much insulin the body
normally releases in response to a whole food or meal (its carbohydrate
and the quantity and quality of its protein and fat). Some foods need
more insulin to help utilise them, while other foods need much less.
Choosing foods with a lower FII can help reduce your overall insulin
demand on your pancreas or insulin requirements,” says dietitian and
diabetes educator Dr Kirstie Bell.
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