Their diets consist of high levels of fruits and vegetables, fermented foods, and surprisingly, high carbs, while keeping fat consumption low. If it's the health properties you're drawn to, however, it's low calorie and rich in vital minerals including iron, copper, vitamin K, magnesium, potassium, selenium, zinc, vitamin C and calcium. While the orange sweet potatoes we know and love have their own wide-ranging health benefits, purple sweet potatoes are particularly popular in Okinawa specifically. This fibre-rich veggie contains high levels of Vitamin C - essential for disease prevention, wound healing, and keeping strong, healthy bones. I spent a week at the world’s most exclusive longevity retreat loved by A-listersBlue Zones: 5 key foods eaten by Ikarians for longevity to add to your dietSign up for our free Indy100 weekly newsletter