Aluminum Bioavailability from the Approved Food Additive Leavening Agent Acidic Sodium Aluminum Phosphate, Incorporated into a Baked Good, Is Lower than from Water

Abstract

There are estimates of oral aluminum (Al) bioavailability from drinking water, but little information on Al bioavailability from foods. Foods contribute ∼95% and drinking water 1–2% of the typical human\u27s 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 26Al. The rats received concurrent 27Al infusion. Blood was repeatedly withdrawn and serum analyzed for 26Al by accelerator mass spectrometry. Total Al was determined by atomic absorption spectrometry. Oral 26Al bioavailability was determined from the area under the 26Al, compared to 27Al, serum concentration × time curves. Oral Al bioavailability (F) from biscuit containing 1% or 2% acidic 26Al-SALP averaged ∼0.11% and 0.13%; significantly less than from water, which was previously shown to be ∼0.3%. The time to maximum serum 26Al concentration was 4.2 and 6 h after consumption of biscuit containing 1% or 2% 26Al-acidic SALP, respectively, compared to 1–2 h following 26Al in water. These results of oral Al bioavailability from acidic 26Al-SALP in a biscuit (F ∼ 0.1%) and results from 26Al in water (F ∼ 0.3%) × the contributions of food and drinking water to the typical human\u27s daily Al intake (∼5–10 mg from food and 0.1 mg from water, respectively) suggest food provides ∼25-fold more Al to systemic circulation, and potential Al body burden, than does drinking water