Three weeks of consuming 12 grams per day of soluble corn fiber added to foods were associated with a 12% increase in calcium absorption, compared to the control, according to research findings published in the British Journal of Nutrition .
“A decrease in milk consumption among adolescents has led to an increase in deficiency of calcium in the diet, leaving researchers with a particular interest in finding functional foods that can help increase calcium absorption,” said Connie Weaver, PhD, from Purdue University and lead researcher of the study.
“Dietary factors that enhance bone density and bone mineral content have the potential to contribute to reduced risk of bone fracture later in life.”
The soluble corn fiber used in the study was added to fruit snacks and provided by Tate & Lyle.
Fibers and bones
The study adds to an every growing body of science supporting the potential bone health benefits of prebiotic fiber intake. Maximizing the build-up of bone during the highly important pubescent years is seen as one of the two best ways to reduce the risk of osteoporosis later in life. About 35% of a mature adult's peak bone mass is built-up during puberty.
The other approach is to boost bone density in high-risk post-menopausal women by improved diet or supplements.
Prebiotic fibers are reported to help bone strength by selectively promoting the growth of beneficial bacteria in the gut, which in turn produce short chain fatty acids. These fatty acids decrease the pH in the intestine, and improve the solubility of the minerals present. Calcium is then better absorbed into the body.
Indeed, the new study found that soluble corn fiber consumption was linked to an increase in specific strains of beneficial gut bacteria, namely the phylum Bacteroidetes, and these increases were positively correlated with increases in calcium absorption.
Dr Weaver and her co-workers recruited 24 boys and girls aged between 12 and 15 to participate in their randomised controlled trial. The adolescents consumed a diet containing less than recommended amounts of calcium (600 mg/d) and were randomly assigned to receive 0 or 12 grams per day of the soluble corn fiber for three weeks.
Results showed that the soluble corn fiber was associated with an average increase in calcium absorption of 12% over the three weeks. Continued consumption of the soluble corn fiber would lead to an estimated additional 41.4 mg/day retained calcium and if persistent over a year would account for an additional 15.1 g of calcium, or about 1.8% of total body calcium, said the researchers.
The results were welcomed by Michael Harrison, PhD, Senior Vice President of New Product Development at Tate & Lyle. “On average, people aren't meeting their fiber or calcium intake goals with the foods they currently consume. Adding fibers with functional health benefits to already consumed foods is a realistic and simple way to help address this global public health concern among key age groups,” he said.
Source: British Journal of Nutrition
2014, Volume 112, Pages 446-456
“Soluble maize fibre affects short-term calcium absorption in adolescent boys and girls: a randomised controlled trial using dual stable isotopic tracers.”
Authors: C.M. Whisner, B.R. Martin, C.H. Nakatsu, G.P. McCabe, L.D. McCabe, M. Peacock, C.M. Weaver