What is the use of bottle gourd oil? It's believed to prevent gray hair and hair fall; also thickens and improves overall condition of hair, causing it to become healthier. Bottle gourd is a vegetable high on water and is a rich source of vitamin C, K and calcium. It helps in maintaining a healthy heart and brings down bad cholesterol levels. The juice is also beneficial for diabetic patients as it stabilizes the blood sugar level and maintains blood pressure.