A study published in 2013 in the journal Circulation found that a high intake of phytochemicals known as flavonoids — which are found in blueberries, as well as other kinds of berries — may reduce the risk of certain heart conditions in young women.However, there are no set criteria for determining what is and what is not a superfood, according to the American Heart Association.
Blueberries often top many lists of superfoods because they are rich in vitamins, soluble fiber and phytochemicals. But the same nutrients found in blueberries are also found in many other kinds of berries, including strawberries and cranberries.
Kiwifruit is labeled a superfood perhaps because it contains a wider range of nutrients compared to some other fruits. A very small study published in 2011 in the Asia Pacific Journal of Clinical Nutrition suggested that consumption of kiwifruit (which also contains serotonin, a hormone that helps induce and maintain sleep) might promote a better night’s rest in people with sleep disorders.Kiwifruit also tops many a list of popular superfoods. Its benefits are similar, for the most part, to berries, melons, citrus fruit, apples and pears, all of which are high in vitamin C and rich in antioxidants. Superfoods are foods — mostly plant-based but also some fish and dairy — thought to be nutritionally dense and thus good for one’s health. Blueberries, salmon, kale and acai are just a few examples of foods that have garnered the “superfood” label.