While I�ve been anxiously waiting to see how others might respond to this question I�ve prepared one of my own:
Phases of the Moon produce two readily observable phenomena at the Earth�s surface. The most immediately obvious effect is the illumination of the night sky provided by the second brightest celestial source, (after the Sun), sunlight reflected by the Moon towards the Earth�s surface. A Full Moon, unobscured by clouds can contribute an intensity of light comparable to a streetlight at 100 metres. The disturbance of sleep patterns attributable to such light could conceivably contribute to the onset of seizures among those suffering from certain varieties of epilepsy although statistical studies have failed to consistently demonstrate a significant correlation between epileptic episodes and
lunar effects
Variations in the gravitational forces felt on the Earth�s surface attributable to the Moon alone are less than one part in a million. Smaller still are the changes due to the combined effect of the various alignments between the Moon and Sun which accompany the changing phases of the Moon. While these minute differences have appreciable effects when accumulated over vast bodies of water producing ocean tides of varying intensity, on the scale of a single human body the gravitational changes that accompany Moon phases are comparable to the difference between weighing yourself in an upstairs or downstairs bathroom or having a fly join you on the scales.
here are results from another study