It is generally accepted that women are more susceptible to the effects of alcohol than men. Ofcourse, everyones physiology is different and there are exceptions to every rule. Some women who drink regularly will have a higher tolerance to alcohol than many men. However, women are, on average, smaller than men and have relatively more fat and less water in their body than men. Alcohol is distributed through the body according to the water content of blood and tissue. It is not soluable in fat. Therefore, if a person has a higher fat content, the alcohol will be distributed in a smaller percentage of body mass.
It has also been found that women have a lower amount of an enzyme in their stomach that breaks down alcohol. The stomach lining contains an enzyme called gastric alcohol dehydrogenase that breaks down alcohol before it can be absorbed into the body. As women have a lower level of this enzyme, they can have higher blood alcohol levels than men based on the consumption of the same amount of alcohol.
This, in part explains why women often have high breath or blood alcohol levels in DUI cases. However, it does not give a complete picture. Research has also suggested that there is an increasing trend in women towards binge drinking. This used to be the preserve of men, but gender equality and perhaps increasing stresses on women finding themselves competing in the job market while trying to build a family as well, has resulted in an increase in alcohol consumption.
There also seems to be an increase in the number of women arrested for DUI in Orange County and Los Angeles based on the consumption of prescribed medications. Sleeping pills, anti-depressants, anti-anxiety medications may all lead to impairment and a DUI arrest, often in circumstances where the defendant was not aware of the risks asssociated with driving after taking medication.
In any event, it is always important to explore the surrounding context of a DUI arrest in building an effective defense. Often there are underlying reasons for the circumstances which may make a difference to how a prosecutor or jury sees the evidence.