Guavas are immunity boosters rich in vitamin C, lycopene and antioxidants. They are also rich in manganese which helps the body to absorb other key nutrients from food. They contain folate, a mineral which helps promote fertility. The potassium in guavas, almost equal to the amount in bananas, helps normalise blood pressure levels as well. Guavas have shown to be widely successful in reducing prostate cancer risk and also inhibit the growth of breast cancer cells since they are rich in lycopene. Guavas may also prevent the development of diabetes. The fibre in guavas regulate sugar levels, and their low glycemic index prevents a sudden spike in sugar levels. Guavas improve the sodium and potassium balance of the body, thereby regulating blood pressure in patients with hypertension. Guavas also help lower triglyceride levels and bad cholesterol (LDL), which lead to heart disease. This amazing fruit improves levels of the good cholesterol (HDL). In terms of dietary fiber, guavas are the richest sources compared to other fruits. A guava a day fulfils about 12% of your daily recommended fibre intake. Due to the presence of Vitamin A, guava is well known as a booster for vision health. It contains one of the highest quantities of vitamin-C and iron among all fruits, making it a key fighter against colds and the flu.