Which one among the following will be absorbed fastest through the wall of digestive system ?

The rate of absorption in the digestive system depends on the chemical nature of the substance and its site of absorption. Most nutrients, such as those in ice cream (fats, proteins) and black coffee (caffeine), require significant chemical digestion or transit to the small intestine for primary absorption [c1, c2, t6]. However, raw alcohol (ethanol) is unique because it is a small, water-soluble, and lipid-soluble molecule that can be absorbed directly through the stomach lining via passive diffusion [t2, t5]. Approximately 20% of alcohol is absorbed in the stomach, while the remainder is absorbed rapidly in the small intestine [t1, t2, t4]. Unlike complex foods that must be broken down into simpler components like amino acids or glucose before entering the bloodstream [c2, t6], alcohol enters the blood almost immediately upon ingestion, making it the fastest-absorbed substance among the given options.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 9: Life Processes in Animals > Small Intestine > p. 126
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Activity 5.3 > p. 86
3. [3] https://pmc.ncbi.nlm.nih.gov/articles/PMC1705129/