Anthocyanins, only found in red or purple onions, are a substantial source of nutrients that promotes clear eye vision. Compared to yellow onions, raw purple onions have a less strong scent and relatively sweeter taste which go well with marinated raw vegetable salad. Purple onions also contain diallyl disulfide that makes a strong garlic smell and considered an important nutrient that can potentially protect against high blood pressure, heart disease, and blood clots. Purple onions help prevent diseases resulted from lifestyle habitats.