Does consuming different types of alcohol make you more sick than others?

Question

A common saying about drinking is this:

Beer before liquor, never been sicker.

Sometimes this is followed by:

Liquor before beer, you're in the clear.

Is there any merit to this? Assuming one drinks the exact same amount of beer and harder alcohol in the exact same time period, all other things being equal, does it matter whether they drink the beer first or drink the shots first?

There are also many other common ideas people have about what gets you sick drinking- one guy might be convinced that having tequila and gin in the same night is a recipe for disaster, while another might feel that mixing wine and beer is. Does the type of drink/combination of drinks matter, or is it strictly a function of the raw amount of alcohol consumed (and the other standard factors such as how long it takes to consume it and if you're drinking on an empty stomach, etc.)?

Reference: http://www.google.com/search?q=beer+before+liquor+never+been+sicker turns up 10000 hits; the top ones all seem to be debunking the first claim.

Answer 1

I've always thought that advice had to do with much lower alcohol concentration of beer making it less dehydrating than distilled spirits. This would be similar to the advice to drink a round of club soda between drinks or a bottle of water before leaving the bar. Other variants being 4oz of water for every ounce of spirits between rounds.

This is from wikipedia

The drug alcohol, specifically ethanol, is a central nervous system depressant with a range of side effects. The amount and circumstances of consumption play a large part in determining the extent of intoxication; for example, consuming alcohol after a heavy meal causes alcohol to absorb more slowly.1 Hydration also plays a role, especially in determining the extent of hangovers.[2]

and

Alcohol has been known to mitigate the production of antidiuretic hormone (ADH), which is a hormone that acts on the kidney, favoring water reabsorption in the kidneys during filtration. This occurs because alcohol confuses osmoreceptors in the hypothalamus, which relay osmotic pressure information to the posterior pituitary, the site of ADH release. Alcohol causes the osmoreceptors to signal that there is low osmotic pressure in the blood, which triggers an inhibition of ADH. Consequently, one's kidneys are no longer able to reabsorb as much water as they should be absorbing, leading to creation of excessive volumes of urine and subsequently overall dehydration.

I am unsure to what extent this is pseudoscience as the wiki article doesn't site any peer reviewed articles on the link between hydration and hangovers.

Answer 2

According to both the Mayo Clinic and Medical News Today, hard liquors contain ingredients known as congeners, which can contribute to a hangover. Different drinks have different congeners, so the same quantity of two different spirits could plausibly produce different after effects. It is at least plausible that mixing your drinks could mean drinking a lot of different congeners, producing a more severe hangover.

At least one controlled study found that drinking bourbon led to more severe hangover symptoms than drinking vodka.

The amount that congeners contribute to a hangover is not specifically known. What is generally agreed on is that you cannot avoid a hangover by not mixing your beverages, the ethanol itself is the greatest contributor to hangover symptoms. So in that sense, it probably isn't true that the order you consume your beverages in is going to prevent you from feeling sick the next day.