Whole-grain rye and wheat foods and markers of bowel health in overweight middle-aged men.
BACKGROUND
Whole-grain cereal foods including rye have been identified as providing significant health benefits that do not occur when refined-cereal foods are ingested.


OBJECTIVE
Foods (90 g) containing whole-grain rye flour and whole-grain wheat flour were compared with low-fiber refined-cereal foods for their effects on markers of bowel health and the metabolic markers insulin and glucose.


METHODS
Three 4-wk interventions were undertaken in a randomized crossover design with 28 overweight men aged 40-65 y who had no history of bowel disease. Against a background intake of 14 g dietary fiber (DF), the men were fed low-fiber cereal grain foods providing 5 g DF for a total of 19 g DF/d. High-fiber wheat foods provided 18 g DF, and high-fiber rye foods provided 18 g DF, both giving a total of 32 g DF/d. Fecal samples (48-h) and fasting and postprandial blood samples were collected at the end of each period and assayed.


RESULTS
Both high-fiber rye and wheat foods increased fecal output by 33-36% (P = 0.004) and reduced fecal beta-glucuronidase activity by 29% (P = 0.027). Postprandial plasma insulin was decreased by 46-49% (P = 0.0001) and postprandial plasma glucose by 16-19% (P = 0.0005). Rye foods were associated with significantly (P = 0.0001) increased plasma enterolactone (47% and 71%) and fecal butyrate (26% and 36%), relative to wheat and low-fiber options, respectively.


CONCLUSIONS
High-fiber rye and wheat food consumption improved several markers of bowel and metabolic health relative to that of low-fiber food. Fiber from rye appears more effective than that from wheat in overall improvement of biomarkers of bowel health.
McIntosh
Graeme H
GH
Commonwealth Scientific & Industrial Research Organisation Health Sciences and Nutrition, Adelaide, Australia. graeme.mcintosh@csiro.au
Noakes
Manny
M
Royle
Peter J
PJ
Foster
Paul R
PR
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000097:blood; D000641:Ammonia / Q000032:analysis; D015415:Biomarkers / Q000032:analysis*; D001786:Blood Glucose / Q000032:analysis; D002087:Butyrates / Q000032:analysis; D003408:Cresols / Q000032:analysis / Q000097:blood; D018592:Cross-Over Studies; D003672:Defecation; D004032:Diet; D004043:Dietary Fiber / Q000008:administration & dosage*; D005243:Feces / Q000737:chemistry; D005502:Food; D005966:Glucuronidase / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000097:blood; D007422:Intestines / Q000502:physiology*; D017705:Lignans / Q000097:blood; D008297:Male; D008875:Middle Aged; D011422:Propionates / Q000032:analysis; D012434:Secale; D014908:Triticum
D015415:Biomarkers; D001786:Blood Glucose; D002087:Butyrates; D003408:Cresols; D004043:Dietary Fiber; D007328:Insulin; D017705:Lignans; D011422:Propionates; C032538:4-cresol; D000641:Ammonia; D005966:Glucuronidase; C029658:propionic acid; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone