Glucose and Insulin Metabolism
Rye products generate a lower postprandial insulin response than wheat products, even though the postprandial glucose response remains unchanged. This response is not only due to the fiber content of rye, but also due to the bioactive components and the physical structure of rye products, e.g. rye breads. Also, there is evidence that grain variety influences the postprandial insulin metabolism, some varieties showing more insulin saving capacity than others.
Hypothetically, repeated lower postprandial insulinemic responses may allow beta cell function to recover or decrease insulin resistance, which improves early insulin secretion over the long term. In line with this hypothesis, it has been established that high-fiber rye bread increased the acute insulin response, but insulin sensitivity remained unchanged in the long run. Furthermore, it has been shown that rye bread and pasta-based carbohydrate modification can enhance early insulin secretion in persons with the metabolic syndrome, although no changes in glucose tolerance or insulin resistance were observed. It has been recently shown that rye bread and pasta based diet down-regulated genes responsible for insulin signaling suggesting that such carbohydrate modifications may influence the risk of type 2 diabetes.
Several clinical studies support the hypothesis that whole grain consumption and especially high intake of cereal fiber is significantly associated with reduced risk of diabetes.
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