Aluminum bioavailability from the approved food additive leavening agent acidic sodium aluminum phosphate, incorporated into a baked good, is lower than from water

There are estimates of oral aluminum (Al) bioavailability from drinking water, but little information on Al bioavailability from foods. Foods contribute similar to 95% and drinking water 1-2% of the typical human's daily Al intake. The objectives were to estimate oral Al bioavailability from a representative food containing the food additive acidic sodium aluminum phosphate (acidic SALP), a leavening agent in baked goods. Rats were acclimated to a special diet that resulted in no stomach contents 14 h after its withdrawal. They were trained to rapidly consume a biscuit containing 1.5% acidic SALP. Oral Al bioavailability was then determined from a biscuit containing 1% or 2% acidic SALP, synthesized to contain Al-26. The rats received concurrent Al-27 infusion. Blood was repeatedly withdrawn and serum analyzed for Al-26 by accelerator mass spectrometry. Total Al was determined by atomic absorption spectrometry. Oral Al-26 bioavailability was determined from the area under the Al-26, compared to Al-27, serum concentration x time curves. Oral Al bioavailability (F) from biscuit containing 1% or 2% acidic Al-26-SALP averaged similar to 0.11% and 0.13%; significantly less than from water, which was previously shown to be similar to 0.3%. The time to maximum serum Al-26 concentration was 4.2 and 6 h after consumption of biscuit containing 1% or 2 % Al-26-acidic SALP, respectively, compared to 1-2 h following Al-26 in water. These results of oral Al bioavailability from acidic Al-26-SALP in a biscuit (F similar to 0.1%) and results from 26 Al in water (F similar to 0.3%) x the contributions of food and drinking water to the typical human's daily Al intake (similar to 5-10 mg from food and 0.1 mg from water, respectively) suggest food provides similar to 25-fold more Al to systemic circulation, and potential Al body burden, than does drinking water. (c) 2006 Elsevier Ireland Ltd. All rights reserved.