Abstract
Background: Fiber and whole-cereal intakes may protect against hyperinsulinemia and the risk of type 2 diabetes.
Objective: The aim was to study whether the long-term use of high-fiber rye bread and white-wheat bread modifies glucose and insulin metabolism in healthy postmenopausal women.
Design: The study was a randomized crossover trial consisting of 8-wk test and 8-wk washout periods. The subjects were 20 postmenopausal women [x̄ ± SD age: 59 ± 6.0 y; body mass index (in kg/m2): 27.5 ± 2.9; baseline fasting serum cholesterol: 6.5 ± 0.8 mmol/L], of whom 3 had impaired glucose tolerance as determined by a 2-h oral-glucose-tolerance test. The test breads were high-fiber rye and white-wheat breads, planned to make up ≥20% of energy. Fasting blood samples were collected for the measurement of plasma glucose and insulin at the beginning and at the end of both bread periods. The frequently sampled intravenous-glucose-tolerance test was performed at the run-in and at the end of both bread periods. The acute insulin response, insulin sensitivity, and glucose effectiveness were calculated.
Results: The rye bread made up 23.4 ± 4.3% and wheat bread 26.7 ± 8.2% of total energy intake. Compared with that during the run-in period, the acute insulin response increased significantly more during the rye bread period (9.9 ± 24.2%) than during the wheat bread period (2.8 ± 36.3%; P = 0.047). Other measured variables did not change significantly during the study.
Conclusions: Modification of carbohydrate intake by high-fiber rye bread did not alter insulin sensitivity in postmenopausal, hypercholesterolemic women. High-fiber rye bread appears to enhance insulin secretion, possibly indicating improvement of b cell function.
Objective: The aim was to study whether the long-term use of high-fiber rye bread and white-wheat bread modifies glucose and insulin metabolism in healthy postmenopausal women.
Design: The study was a randomized crossover trial consisting of 8-wk test and 8-wk washout periods. The subjects were 20 postmenopausal women [x̄ ± SD age: 59 ± 6.0 y; body mass index (in kg/m2): 27.5 ± 2.9; baseline fasting serum cholesterol: 6.5 ± 0.8 mmol/L], of whom 3 had impaired glucose tolerance as determined by a 2-h oral-glucose-tolerance test. The test breads were high-fiber rye and white-wheat breads, planned to make up ≥20% of energy. Fasting blood samples were collected for the measurement of plasma glucose and insulin at the beginning and at the end of both bread periods. The frequently sampled intravenous-glucose-tolerance test was performed at the run-in and at the end of both bread periods. The acute insulin response, insulin sensitivity, and glucose effectiveness were calculated.
Results: The rye bread made up 23.4 ± 4.3% and wheat bread 26.7 ± 8.2% of total energy intake. Compared with that during the run-in period, the acute insulin response increased significantly more during the rye bread period (9.9 ± 24.2%) than during the wheat bread period (2.8 ± 36.3%; P = 0.047). Other measured variables did not change significantly during the study.
Conclusions: Modification of carbohydrate intake by high-fiber rye bread did not alter insulin sensitivity in postmenopausal, hypercholesterolemic women. High-fiber rye bread appears to enhance insulin secretion, possibly indicating improvement of b cell function.
| Original language | English |
|---|---|
| Pages (from-to) | 385-391 |
| Number of pages | 7 |
| Journal | The American journal of clinical nutrition |
| Volume | 77 |
| Issue number | 2 |
| Publication status | Published - 2003 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- rye
- wheat
- fiber
- insulin sensitivity
- insulin secretion
- glucose
- women
