However, these effects are generally modest and should not be viewed as a replacement for medical treatment. Guava or guava leaf tea is best considered a supportive dietary addition rather than a standalone solution.
For people with or at risk of diabetes, the most effective approach still involves balanced nutrition, regular physical activity, and guidance from a healthcare professional.
Eating whole guava in reasonable portions—especially with the skin—can be a healthier choice compared to high-sugar processed snacks, but portion size still matters.
While early research on guava leaves is interesting, more large-scale clinical studies are needed to confirm how strong and consistent these effects are in humans.
Overall, guava can be part of a healthy diet, but it works best as one piece of a broader lifestyle approach to blood sugar control.