Greek / Cretan Avocado Variety Williams. Avocados are known as nutrient boosters because they allow the body to absorb more fat-soluble nutrients than the foods eaten with them. Avocados also provide the same many essential nutrients as fiber, potassium, vitamin E, B vitamins and folic acid and contain more protein than any other fruit. They are known to be high in fat and are actually only secondary to olives in oil content between fruits, but avocado oil is high in monounsaturated fatty acids, which is relatively healthy and can actually help reduce blood cholesterol levels. Avocados come in a variety of colors, some of which are pictured here. As the avocado ripens, the color often changes in a characteristic way of the variety.