Thiamine Interactions

Alcohol depletes thiamine (vitamin B1) at multiple levels — reducing its absorption from the gut, impairing the liver's ability to convert it to its active form, and increasing how much is lost in urine. In heavy drinkers this can lead to Wernicke encephalopathy, a neurologic emergency, which if untreated may progress to Korsakoff syndrome, a chronic and often irreversible memory disorder.

Black tea contains antithiamine factors - polyphenols such as tannins and chlorogenic acid - that can oxidise thiamine (vitamin B1) into biologically inactive forms in the gut before it is absorbed. Heavy habitual tea consumption has been linked to lower thiamine status, mainly in people whose dietary B1 intake is already marginal. For most well-nourished adults the effect is modest.