Possible Testosterone Explanation
The Effect of Alcohol Consumption on the Urinary Testosterone /
Epitestosterone Ratio
By Dr Simon Davis B.Sc., Ph.D.
Summary
Intoxicating beverages contain a number of different forms of alcohol,
the major constituent of which is ethanol. When a beverage is consumed
the ethanol content passes through the stomach wall and digestive tract
into the blood stream. Once the ethanol enters circulation it begins
to alter the bodies' biochemistry. One such reaction is to
differentially increase the rates of testosterone (T) and
epitestosterone (E) metabolism. The overall effect of this reaction is
to increase the ratio of T to E excreted in the urine.
It has been reported that ethanol consumption can increase urinary T/E
ratios by 30% - 277% in healthy individuals. Observed changes in
plasma T/E ratios can occur with the consumption of less than 2 pints
of lager. The ingestion of ethanol by an individual will increase the
T/E ratio observed in a urine sample.
It follows that if the effect of ethanol on T/E ratios is calculated
relative to urinary E concentrations, it can be seen that increases in
the ratio are exponential as E concentrations decrease. Individuals
with naturally low E concentrations could, therefore, experience
increases in T/E ratios of ? 940% greater than increases experienced in
an individual with normal E concentrations. Calculations estimate
that in individuals with low urinary E concentration, ratios of 17 to 1
or higher could have resulted from ethanol consumption without any
administration of exogenous T.
The current T/E ratio test as performed by Kings College Laboratory and
approved by the UK Sports, the IWF and IOC cannot discriminate between
a 13 to 1 T/E ratio resulting from ethanol ingestion or a 13 to 1 ratio
resulting from endogenous T administration.