Carbohydrates and heartburn

[Osprey101]

Some months ago, I started a specialized diet; it contains relatively few carbohydrates, and my persistent heartburn went away. I didn't think much of it until I discovered the writings of Dr. Wolfgang Lutz, who notes that:

"Distressing heartburn is often the first symptom to disappear following withdrawal of carbohydrates from the die However severe, and even if made worse by factors like the back-flow of gastric juice into the esophagus in hiatal hernia, the chances of success are good. If patients come back with the complaint that the diet is no longer effective and their heartburn has returned, a closer look usually reveals that some carbohydrates have again crept into the diet. Or a gastrointestinal infection cam be suspected - and treated."

I'm a biochemist, and I don't know enough gastroenterology to figure out why this happens. My only theory is that carbohydrates increase the osmolarity of the stomach contents enough to draw more acid from the stomach walls (as proteins and fats would have a much lower contribution to osmolarity), but that seems simplistic at best.

Anyone have any insights or theories as to why this is? Thanks in advance.