Acute and Chronic Effects of Honey and Its Carbohydrate Constituents on Calcium Absorption in Rats

Acute and Chronic Effects of Honey and Its Carbohydrate Constituents on Calcium Absorption in Rats

Journal of Agricultural and Food Chemistry
Ariefdjohan, Martin, Lachcik, and Weaver: 2008, 56, 2649–2654
The effects of honey and its carbohydrate constituents (glucose, fructose, and raffinose) on calcium absorption in rats were investigated in acute and chronic feeding studies. In the acute study, rats (n=120) were gavaged with an oral solution consisting of (a) 10 µCi Ca, (b) 25 mg of calcium as calcium acetate, and (c) one of the following: 0 mg of honey (control), or 200, 500, or 800 mg of honey, a glucose fructose mixture, 10.75 mg of raffinose, or 200 mg of raffinose. Another group received Ca intraperitoneally. Femurs were collected 2 days later and analyzed for Ca content. Rats given 500 and 800 mg of honey showed 25.5 and 33.6% increases in calcium absorption (P < 0.05), respectively, over the control group. Groups given the glucose fructose mixture or 200 mg of - raffinose had a significantly higher increase in calcium absorption than the control group (17.1 and 25.6%, respectively). In the chronic study, rats (n 96) were fed for 8 weeks with either 0% honey (control), 5% honey, 10% honey, or a glucose fructose raffinose (GFR) mixture. Femurs of GFR-fed rats had significantly lower calcium content, Ca absorption, width, and BMD (at distal region) than control rats. Groups fed honey did not show the negative effects of GFR on bone, but had no advantage over the control group. No significant differences were observed in femur length, density, strength, or BMC among any treatment group compared to the control group. These results indicate that although a positive dose–response effect of honey and its carbohydrate constituents on calcium absorption was observed in the acute study, this effect disappeared upon long-term feeding in rats, implying adaptation had occurred.