There is one other health benefit that you can gain from drinking guava juice that you might not know about. In Asia, guava is used to treat diabetes. It seems that guava has the ability to increase insulin concentration.
In one animal study, guava was found to lower blood glucose levels in diabetic mice. This effect was repeated in human patients. Keeping the level of sugar, or glucose, in your blood as close to normal as possible is necessary for good health. Many complications can happen as a result of elevated blood glucose, some of them quite serious.