“What disease did ‘cured ham’ actually have?” (joke)

“What disease did ‘cured ham’ actually have?” is a one-liner listed in many joke collections. A ham is “cured” with salt and nitrates to prevent the growth of unhealthy bacteria.
 
“What disease did ‘cured ham’ have?” has been cited in print since at least November 2003.
 
   
Wikipedia: Ham
Curing process
Ham is uncooked preserved pork. It is cured (a preservation process) usually in large quantities of salt and sugar. Then hot smoked (hung over a hot, smokey fire but out of direct heat) to preserve it more. This process keeps the pink hue of the uncooked meat. Standard pork, like chops, are raw and unpreserved. When heat is applied to the meat a chemical reaction happens that turns the hemoglobin white. This also happens when an acid is applied to meats.
 
The pink color of ham develops in the curing process which involves salt and usually either nitrites or nitrates. The nitrate cure is used for product that will either be kept a long time or at room temperature like dry salami. Most hams are cured with nitrite and salt today.
 
The cure prevents the growth of unhealthy bacteria (maybe deadly) before enough moisture is withdrawn by the salt. This is particularly important if the product is to be smoked above 40F when these bacteria grow. The “danger zone” for uncured product is between 40F and 140F.
 
There is confusion in the words curing and brining. Brining is done with salt and usually sugar and only alters the product color a little. Curing is done with salt and nitrates.
 
Sodium nitrite is used for the curing of meat because it prevents bacterial growth and, in a reaction with the meat’s myoglobin, gives the product a desirable dark red color.
   
13 November 2003, The Advocate (Baton Rouge, LA), Smiley Anders column:
And Donald Henderson of Watson asks, “What disease did ‘cured ham’ have?”
     
eBaum’s World
SoulS Sword
06-07-2005, 03:54 PM
Impossible Questions of DOOM
(...)
What disease did cured ham actually have?
   
Google News Archive
11 August 2005, DeFuniak Springs (FL) Herald, “A wink and a smile” by Ron Kelley, pg. 4A, col. 2:
What disease did cured ham actually have?
 
8 March 2006, Preston County Journal (Kingwood, WV), “Reflections” by Marilyn H. Snyder, pg. 10, col. 2:
What disease did cured ham actually have?
 
SodaHead
What disease did cured ham actually have?
by 666_Maggots~PassionForGloryPostedApril 06, 2012