When I was a little kid, I would wake up early in the morning before school and watch cartoons. I remember watching, among other things, George of the Jungle and Popeye.
Popeye, of course, was the sailor who had a romantic interest in Olive Oyl. Unfortunately for Popeye, so did his archnemesis Bluto (later known as Brutus), a burly, bearded brute who liked to give Popeye trouble. But there was never any real concern that Bluto would win the day. All Popeye had to do was gulp down a can of spinach, and with his bulging muscles, pound Bluto into oblivion.
Spinach, in other words, was among America's first superfoods. Alas, science shows that "superfoods" aren't real.
The Superfood Phenomenon
Let's consider spinach. Research suggests that the nitrates found in spinach might help muscles grow, albeit not as quickly as Popeye would have you believe. But spinach isn't the only food that contains a lot of nitrate. Grains and other vegetables, like beets, are also good sources of nitrate. Besides, simply stuffing your face full of spinach isn't going to make you noticeably bulkier; you'll need to hit the gym, as well. So, while spinach is certainly very healthy, it is not a superfood.
Similar reasoning goes for every other superfood fad that has existed. Milk. Blueberries. Yogurt. Fish. All of these (and more) have been touted as superfoods at various times. However, food isn't magical. Food is simply a delicious collection of humanity's favorite molecules, some of which have health benefits and some of which do not. At the end of the day, you need to consume a diet that is balanced in such a way that you get all the healthy molecules your body needs.
Apples are a great source of fiber. But if you don't like (them) apples, you can eat oatmeal, instead, because it is also high in fiber. The point is that there are a nearly infinite combination of foods that you can eat to satisfy your body's dietary requirements.
Why Do Americans Believe in Superfoods?
So, if superfoods aren't real, then why do so many Americans believe in them? The superfood phenomenon is likely the result of: (1) Our cultural obsession with quick fixes and easy answers to complex questions; and (2) Marketing gimmicks that take advantage of widespread scientific illiteracy.
This also explains why superfoods are always fads that go in and out of style like goatees. If people don't understand the science of nutrition, they easily will be influenced by marketers looking to sell something and by activists seeking to scare them.
Got milk? At one time, milk was considered a superfood. Now, thanks to activists like PETA, people think milk is bad for them. The truth is really boring: Milk is a perfectly healthy food. But if you don't like it, fine. You can get the calcium, fat, protein, and carbohydrates found in milk somewhere else.
Might I suggest tofu?