Unfortunately, at this point in time, there is no scientifically based or governmental regulated definition of superfoods. However, most foods that are advertised as such tend to offer higher levels. of certain nutrients, is said to prevent certain diseases, or is claimed to provide certain health benefits beyond the nutrients it contains.
The term itself appears to have originated in the early 20th century around the time of World War 1 as part of a food marketing campaign. It was used by the United Fruit Company to promote the bananas it imported into the United States. They spoke about how nutritional they were, how they could be used, and so much more so people would buy it.
The term started to take off when it began appearing in medical journals as doctors began publishing their results of using bananas to treat various diseases such as celiac's disease or diabetes. Even the American Medical Association used the term when they announced that a child who regularly ate bananas would either find relief from celiac's disease or be cured of it. This all lead to a crazy banana diet.
In current times, with the vastness of social media and the internet, the announcement of a "superfood" spreads rapidly across the world. Thus for people who sell the food, it can translate into multimillion dollar sales because people are willing to pay more for foods that are seen as healthier either naturally or via various claims. This is especially true of people who see food as medicine. In addition, when the food industry markets a food as a superfood, sales of that item are likely to increase so anything with superfood on the label is considered a hot product.
There have been studies done on many of these superfoods to see how much of what nutrients they offer and their health properties but there haven't really been any studies done to see how these properties apply to a person's diet. This is due to the fact that the laboratory conditions used to study the food are extremely difficult to apply to a person's diet. It has also been found that the benefits are often of short duration and people would have to eat frequent portions to experience the continued benefits. Finally, most studies look at the food in isolation, not in combination with other foods which is the normal way people consume these products.
Although superfoods are more national in general, the label seems to motivate sales and can cause people to ignore other foods and focus on a select few. It is important to eat a wide variety of foods for the best nutrition, the best amount of vitamins and minerals, and is so much better for us. So rather than focusing on superfoods, look at eating a well balanced diet containing different foods. Let me know what you think, I'd love to hear. Have a great weekend.