Manipulation of lipid bioaccessibility of almond seeds influences postprandial lipemia in healthy human subjects.
BACKGROUND
Plant cell walls are known to influence the rate and extent of lipid release from plant food tissues during digestion; however, the effect of cell wall structure on postprandial lipemia is unknown.


OBJECTIVE
The objective was to investigate the effects of lipid release (bioaccessibility) on postprandial lipemia by comparing lipid encapsulated by cell walls with lipid present as free oil.


METHODS
A randomized crossover trial (n = 20 men) compared the effects of 3 meals containing 54 g fat provided as whole almond seed macroparticles (WA), almond oil and defatted almond flour (AO), or a sunflower oil blend as control (CO) on postprandial changes in oxidative stress (8-isoprostane F(2)alpha concentrations), vascular tone (peripheral augmentation index), and plasma triacylglycerol, glucose, and insulin concentrations.


RESULTS
The postprandial increase in plasma triacylglycerol was lower [74% and 58% lower incremental area under curve (iAUC)] after the WA meal than after the AO and CO meals (P < 0.001). Increases in plasma glucose concentrations (0-180 min) were significantly higher after the WA meal (iAUC: 114; 95% CI: 76, 153) than after the AO meal (iAUC: 74; 95% CI: 48, 99) (P < 0.05), but no significant differences from the CO meal were observed (iAUC: 88; 95% CI: 66, 109). The peak reductions in peripheral augmentation index after the WA, AO, and CO meals (-9.5%, -10.1%, and -12.6%, respectively, at 2 h) were not significantly different between meals. Plasma 8-isoprostane F(2)alpha and insulin concentrations did not differ significantly between meals.


CONCLUSIONS
The bioaccessibility of lipid in almond seeds, which is regulated by the structure and properties of cell walls, plays a primary role in determining postprandial lipemia.
King's College London, Nutritional Sciences Division, Franklin-Wilkins Building, London, UK. sarah.e.berry@kcl.ac.uk
Sarah E E
SE
Berry
Elizabeth A
EA
Tydeman
Hannah B
HB
Lewis
Ravneet
R
Phalora
Jennifer
J
Rosborough
David R
DR
Picout
Peter R
PR
Ellis
D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D001682:Biological Availability; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000493:pharmacokinetics*; D004063:Digestion; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005433:Flour; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology*; D007328:Insulin / Q000097:blood; D007408:Intestinal Absorption; D008055:Lipids / Q000097:blood*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D010938:Plant Oils; D019518:Postprandial Period / Q000187:drug effects; D027861:Prunus / Q000737:chemistry*; D012639:Seeds; D000074242:Sunflower Oil; D014280:Triglycerides / Q000097:blood*
D001786:Blood Glucose; D004041:Dietary Fats; D007328:Insulin; D008055:Lipids; D010938:Plant Oils; D000074242:Sunflower Oil; D014280:Triglycerides; C068582:almond oil