Does wholegrain have lower glycemic?
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Wholegrain Foods and Their Impact on Glycemic Response
Introduction to Wholegrain and Glycemic Index
Wholegrain foods have been widely promoted for their health benefits, particularly in managing blood glucose levels. The glycemic index (GI) measures how quickly foods cause increases in blood glucose levels. Foods with a lower GI are digested and absorbed more slowly, leading to a gradual rise in blood sugar and insulin levels. This article synthesizes research findings on whether wholegrain foods have a lower glycemic response compared to their refined counterparts.
Wholegrain vs. Refined Grains: Glycemic Response
Wholegrain Breads and Glycemic Index
Research indicates that wholegrain breads, which contain a higher proportion of whole cereal grains, tend to have a lower glycemic index compared to breads made from milled flour. A study involving diabetic volunteers showed that increasing the proportion of whole cereal grains in bread significantly lowered the glycemic index and in vitro digestibility, suggesting that these breads are digested more slowly and could help in reducing postprandial blood glucose levels.
Wholegrain Wheat Products
In a study comparing wholegrain wheat bread and pasta to their refined counterparts, it was found that wholegrain wheat bread increased satiety and reduced hunger, although it did not significantly affect subsequent energy intake. The glycemic responses were similar for wholemeal and refined products, but pasta meals, particularly refined wheat pasta, showed significantly lower glucose responses.
Processing and Particle Size
The degree of processing of wholegrains also plays a crucial role in glycemic control. Less processed wholegrain foods were shown to improve glycemic measures in adults with type 2 diabetes. Specifically, postprandial glucose responses were lower following meals with less processed whole grains compared to finely milled grains. Additionally, the structural integrity of wholegrain in bread influences glycemic response, with larger particle sizes associated with lower postprandial glycemia.
Specific Wholegrains and Glycemic Control
Wholegrain Oats
Wholegrain oat-based cereals have been identified as having a low glycemic index and prebiotic potential. Studies have shown that these cereals can lower blood glucose levels and contribute to a low-glycemic load diet. The consumption of wholegrain oat cereals was associated with significant increases in beneficial gut bacteria, which may further support metabolic health .
Diverse Wholegrains
Different wholegrains, such as barley, buckwheat, and quinoa, vary in their nutritional composition and glycemic impact. Porridges made from oats, quinoa, or buckwheat are considered healthier due to their lower glycemic index, higher digestible protein content, and higher dietary fiber content.
Long-term Health Implications
Type 2 Diabetes and Cardiovascular Disease
Long-term studies have shown that diets with a lower glycemic index and load are associated with a reduced risk of type 2 diabetes. Wholegrain foods, which typically have a lower glycemic index, are recommended as part of a healthy diet to manage and prevent diabetes. Additionally, wholegrain consumption has been linked to a reduced risk of coronary heart disease and stroke, emphasizing the importance of wholegrain foods in cardiovascular health.
Conclusion
Wholegrain foods generally have a lower glycemic response compared to refined grains, making them beneficial for managing blood glucose levels and reducing the risk of chronic diseases such as type 2 diabetes and cardiovascular disease. The degree of processing and the structural integrity of wholegrains are important factors influencing their glycemic impact. Incorporating a variety of wholegrains, particularly less processed options, into the diet can provide significant health benefits.
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