It was originally thought that it would help prevent bloat.
Here's the purdue study:
http://www.vet.purdue.edu/epi/bloat.htm
http://www.vetinfo4dogs.com/dbloat.html#Elevated%20food%20bowels%20and%20bloat
http://www.moonstruckmeadows.com/Bloat%20(GDV)%20Study.htm
After talking to my vet, doesn't really make a difference bloat wise. Either the dog is predisposed or it isn't.
Now, I do have my senior male Vishnu eating and drinking from a raised bowl as he has HD and elbow dysplasia very severe at this point and it is more of a comfort level for him at this point.
From one of the links above: These four (4) factors ARE associated with an increased risk of bloat in large breed dogs
1)Raising the food dish more than doubled the risk for bloat
2)Speed of eating -Dogs rated by their owners as very fast eaters had a 38% increased risk of bloat
3)Age: The study found that risk increased by 20% with each year of age. Owners should be more alert to early signs of bloat as their dogs grow older.
4)Family History: Having a first-degree relative (parent, sibling or offspring) that had bloated increased a dog's risk by 63%.