From an [NHS website](http://www.nhs.uk/chq/Pages/853.aspx?CategoryID=87&SubCategoryID=871):

> 
> To lower your risk of health problems, the NHS recommends that:
> 
> 
> men should not regularly drink more than 3-4 units of alcohol a day
> 
> 
> women should not regularly drink more than 2-3 units of alcohol a day
> 
> 
> 'Regularly' means drinking these amounts every day or on most days of
> the week.
> 
> 
> 

Do these figures have any scientific basis?