Is lactase hard to digest? The surprising truth about this key enzyme
                                
                                
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                                    4 min read                                
                            
                                According to MedlinePlus, approximately 65 percent of the human population has a reduced ability to digest lactose after infancy, but this is not because the enzyme lactase is hard to digest. The truth is that lactase, an enzyme, is not what causes digestive problems; rather, it is the deficiency of this enzyme that leads to difficulty processing the milk sugar, lactose.