title: Whole-grain foods do not affect insulin sensitivity or markers of lipid peroxidation and inflammation in healthy, moderately overweight subjects.
abstract: High intakes of whole grain foods are inversely related to the incidence of coronary heart diseases and type 2 diabetes, but the mechanisms remain unclear. Our study aimed to evaluate the effects of a diet rich in whole grains compared with a diet containing the same amount of refined grains on insulin sensitivity and markers of lipid peroxidation and inflammation. In a randomized crossover study, 22 women and 8 men (BMI 28 +/- 2) were given either whole-grain or refined-grain products (3 bread slices, 2 crisp bread slices, 1 portion muesli, and 1 portion pasta) to include in their habitual daily diet for two 6-wk periods. Peripheral insulin sensitivity was determined by euglycemic hyperinsulinemic clamp tests. 8-Iso-prostaglandin F(2alpha) (8-iso PGF(2alpha)), an F(2)-isoprostane, was measured in the urine as a marker of lipid peroxidation, and highly sensitive C-reactive protein and IL-6 were analyzed in plasma as markers of inflammation. Peripheral insulin sensitivity [mg glucose . kg body wt(-1) . min(-1) per unit plasma insulin (mU/L) x 100] did not improve when subjects consumed whole-grain products (6.8 +/- 3.0 at baseline and 6.5 +/- 2.7 after 6 wk) or refined products (6.4 +/- 2.9 and 6.9 +/- 3.2, respectively) and there were no differences between the 2 periods. Whole-grain consumption also did not affect 8-iso-PGF(2alpha) in urine, IL-6 and C-reactive protein in plasma, blood pressure, or serum lipid concentrations. In conclusion, substitution of whole grains (mainly based on milled wheat) for refined-grain products in the habitual daily diet of healthy moderately overweight adults for 6-wk did not affect insulin sensitivity or markers of lipid peroxidation and inflammation.
authors.affiliation: Clinical Nutrition and Metabolism, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden. agneta.andersson@pubcare.uu.se
authors.forename: Agneta
authors.initials: A
authors.lastname: Andersson
authors.forename: Siv
authors.initials: S
authors.lastname: Tengblad
authors.forename: Brita
authors.initials: B
authors.lastname: Karlström
authors.forename: Afaf
authors.initials: A
authors.lastname: Kamal-Eldin
authors.forename: Rikard
authors.initials: R
authors.lastname: Landberg
authors.forename: Samar
authors.initials: S
authors.lastname: Basu
authors.forename: Per
authors.initials: P
authors.lastname: Aman
authors.forename: Bengt
authors.initials: B
authors.lastname: Vessby
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D015992:Body Mass Index; D018592:Cross-Over Studies; D004032:Diet; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000652:urine; D002523:Edible Grain; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000652:urine; D007328:Insulin / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D050177:Overweight
chemical_list: D007328:Insulin; D015850:Interleukin-6; D008055:Lipids; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost