Checking glycemic index with NIR light
TSUKUBA, Japan – Reliable and noninvasive ways to check blood sugar have proved elusive,
but a new effort by scientists at the National Food Research Institute could bring
a near-infrared spectroscopy-based approach a step closer.
NIR seems tailor-made for glucose monitoring, but because conditions
under which the test would have to be run vary so widely, a clinically acceptable
method has not yet been devised.
The researchers report that they have achieved real progress,
thanks to an approach that eliminates the person-to-person variation and involves
sensing over a larger area of skin than had been attempted previously.
The glycemic index of foods can indicate the influence of that
food on blood glucose levels, but glycemic index measurements are invasive as well
as expensive in terms of both time and money. It works as follows: Taking a series
of blood samples, scientists check the increase in blood glucose after a standard
amount of a carbohydrate is consumed.
In the present study, the researchers demonstrated that the glycemic
index can be determined without excessive blood sampling. They illuminated the palm
of the hand, among other body parts, and then measured the light emitted, comparing
it to previous measurements. Skin pigmentation did not affect the results, they
The team now is using the technology to determine the glycemic
index values of various foods. Their findings were published in the Journal of Near
Infrared Spectroscopy, Vol. 18, Issue 5, pp. 291-300 (2010).
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