Chia seeds are tiny black seeds from the plant Salvia hispanica, which is related to the mint. Chia seeds were an important food for the Aztecs and Mayans back in the day. They prized them for their ability to provide sustainable energy.Chia seeds are among the healthiest foods on the planet.They’re loaded with nutrients that can have important benefits for your body and brain. They are now added to a variety of foods to boost nutrient content, such as granolas, cereals, yogurts and energy drinks.