Whole-grain cereal foods, including rye, have been identified as providing significant health benefits. These benefits do not occur when refined-cereal foods are ingested.
In this study, researchers from Australia compared foods containing whole-grain rye and wheat flour with low-fiber refined-cereal foods. They looked at the effects of these foods on markers of bowel health and metabolic markers, insulin and glucose.
The research team performed a randomized crossover study.
|Rye foods were significantly associated with increased plasma enterolactone.|
|American Journal of Clinical Nutrition|
They assessed 28 overweight men aged 40 to 65 years, who had no history of bowel disease.
The team fed subjects low-fiber cereal grain foods providing 5 g dietary fiber (DF), against a background intake of 14 g DF. Their total intake was 19 g DF per day.
In contrast the high-fiber wheat and rye foods provided 18 g of DF each, giving a total of 32 g DF per day.
In addition, the team collected 48-hour fecal samples, as well as fasting and postprandial blood samples, at the end of each period. These were assayed.
The researchers found that both high-fiber rye and wheat foods increased fecal output by 33 to 36%, and also reduced fecal beta-glucuronidase activity by 29%.
In addition, the high-fiber foods decreased postprandial plasma insulin by 46 to 49% and postprandial plasma glucose by 16 to 19%.
The team found that rye foods were significantly associated with increased plasma enterolactone and fecal butyrate, compared to wheat and low-fiber options.
Dr Graeme McIntosh's team concluded, "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."