Fig. 1.

Schematic of the experimental protocol. After obtaining baseline blood tests and questionnaires, subjects wore a wrist actiwatch and were told to abstain from alcohol for 1 wk. A 24-h phase assessment was then done in the Biological Rhythms Lab where subjects were kept under dim light conditions (<5 lux) and constant posture. An iv was inserted to draw hourly plasma melatonin, every 4 h peripheral blood mononuclear cells (PBMCs) for clock gene expression, and a 24-h urine collection after sugar challenge for intestinal permeability. Subjects were then given red wine and told to drink 2–4 glasses of wine a day for ∼0.5 g of alcohol/kg body wt before repeating an identical 24-h phase assessment.