According to a number of websites, "almost everything you have been told about heartburn, indigestion, and common stomach ailments are lies", and heartburn is actually caused by too little stomach acid.
The truth about most stomach disorders is that they are caused by not having enough acid, so the industry has made fools out of most of us. The true reason behind acid reflux and indigestion is that when the stomach is lacking enough acid, it must churn violently to make the best use of its limited acid during these times of deficiency, which in turn causes pressure and back flows of the existing acid.
Drinking apple cider vinegar is supposed to fix this by adding acid to the stomach.
The science behind the apple cider vinegar cure for heartburn is simple–the stomach uses natural acids to digest food, and apple cider vinegar is very similar in acidity to your stomach acid. Heartburn happens when there is too little acid in the stomach itself to digest your food.
Some people who experience heartburn may not have enough digestive acid.. Apple cider vinegar is acidic in nature and thus it helps. If the sphincter esophagael contains the acid, it closes the LES (lower esophageal sphincter) to protect the esophagus by reflux. And the LES is to open at regular intervals when there is too little acid.
Is there any truth to this? I tried apple cider vinegar once, and not only does it taste and smell terrible, it made my heartburn worse.