The effects of fiber enrichment of pasta and fat content on gastric emptying, GLP-1, glucose, and insulin responses to a meal.
OBJECTIVE
To assess whether the addition of viscous fiber at an amount recommended by the US FDA to allow a 'low saturated fat, cholesterol, soluble fiber and coronary heart disease', health claim label on a food package (1.7 g psyllium) and/or fat (30 g sunflower oil and 3 g sodium propionate) to a pasta meal would affect gastric emptying, postprandial glucose, insulin and GLP-1 concentrations.


METHODS
Ten subjects participated in a two-by-two single blind randomized crossover study. Four meals containing 50 g of available carbohydrate were consumed: pasta with or without psyllium enrichment served with a tomato sauce with (520 kcal per meal) and without (240 kcal per meal) fat. Blood samples were taken for 240 min following the meal and all subjects consumed a buffet meal at the end of the study. Gastric emptying was measured using the paracetamol absorption test. Blood was analysed for glucose, insulin, GLP-1. Visual analog scales were used to record feelings of hunger, pleasantness and nausea.


RESULTS
The psyllium-enriched pasta had no significant effect on gastric emptying or the incremental area under the curve (IAUC) for GLP-1, insulin or glucose compared with the control pasta. The addition of polyunsaturated fat and sodium propionate significantly increased the IAUC for GLP-1 (P<0.001), delaying gastric emptying (P<0.002), and decreasing glucose (P<0.002).


CONCLUSIONS
A dose of 1.7 g psyllium did not evoke measurable effects on gastric emptying, postprandial GLP-1, insulin or glucose metabolism. However the addition of 30 g of oil and 3 g of sodium propionate to the pasta did reduce gastric emptying, increase GLP-1 and reduce glucose and insulin concentrations. While this short-term study may have implications in terms of reducing the risk of diabetes and improving coronary risk factor profiles the long term effects of these nutrients need to be studied.
Frost
G S
GS
Nutrition and Dietetic Research Group, Hammersmith Hospital, London, UK. gfrost@ic.ac.uk
Brynes
A E
AE
Dhillo
W S
WS
Bloom
S R
SR
McBurney
M I
MI
D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D001786:Blood Glucose / Q000187:drug effects*; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000494:pharmacology*; D004043:Dietary Fiber / Q000494:pharmacology*; D005260:Female; D005527:Food, Fortified; D005746:Gastric Emptying / Q000187:drug effects*; D005934:Glucagon / Q000097:blood* / Q000187:drug effects*; D052216:Glucagon-Like Peptide 1; D006801:Humans; D006815:Hunger / Q000187:drug effects; D007328:Insulin / Q000097:blood*; D008297:Male; D010446:Peptide Fragments / Q000097:blood* / Q000187:drug effects*; D011498:Protein Precursors / Q000097:blood* / Q000187:drug effects*; D012016:Reference Values; D016037:Single-Blind Method; D013997:Time Factors; D014908:Triticum
D001786:Blood Glucose; D004041:Dietary Fats; D004043:Dietary Fiber; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D052216:Glucagon-Like Peptide 1; D005934:Glucagon