• Some of the studies performed are just bad science, with insufficient individuals or extreme bias in the testing sample, or shady conclusions that lean more on desired commercial than healthful effects.
• The conditions under which foods are tested in the lab are very different from real-life consumption.
• The high levels of nutrients tested are extremely unrealistic in the context of every-day diets. 
• Health-promoting effects are short term. People would need to consume these superfoods very often to reap the goodies, which could easily prove counterproductive (cocoa v chocolate, for example). This is never stressed enough and, by the by, happens in many other aspects of our consumer society.
• Studies tend to happen on animals or in vitro. They serve as guidance on the kinds of effects and physiology at stake on humans, but one can never be sure of their exact impact under real-life dietary conditions. Science needs a different approach to human impact, one that takes into account the meandering genetics and lifestyles of individuals… probably more interventional, observational, protracted, and costly studies.
• Tests tend to study foods in isolation. This bears no resemblance to reality because people consume in combination patterns. For example, there is now ample evidence that certain co-consumption pairings actually boost benefits.

The label super, while very appealing, impinges on your range of selection, implying that other foods are sub-par. This can prove extremely harmful to our intelligence first, and to our bodies ultimately.

Much to our dismay, the abundantly cheaper options at our disposal do not get the rap they deserve. Onions, garlic, apples, lentils or squash/pumpkin, among many others, lack the sexiness or exoticism of these superfoods, but are jam-packed with healthful nutrients and properties as well.

The idea that some foods have miracle healing properties, a salacious claim pushed by corporations and journalism on a population that’s us, that is either too ignorant or too lazy to actively confront it, leads many to neglect healthy lifestyles. You still need to exercise or dramatically cut down on drinking and smoking, even if you are hoarding on acai. And, NO, if you add Goji berries or Chia seeds to processed foods, it does not counteract, make up for or constitute a healthy diet.
 

Of course, the superfood craze also dabbles in and rides the crest of this supermyth. Being slim does not mean you are healthy. Our society thinks it is more desirable as a whole, but the size and shape of our bodies do not determine our health. Overweight individuals who exercise and have balanced diets and lifestyles are certainly in better overall shape than slender people who do not make these choices.

All good science and sound medical advice has called you to cut back on added sugars and sweeteners, the ones you can find on processed foods and drinks, like sodas, cookies, cakes, some breads, etc. But foods that are naturally sweet are fine. Heck, international organisms are continuously recommending we up our intake of fruit in general. Most fruits include fiber as well, which slows down the absorption of their natural sugars.

On the one hand, are you 100% sure that the celebrity is not just endorsing a diet as a sellable product or byproduct? On the other, celebrities such as actors or models have a ton of help because part of their livelihood depends on their image and healthful looks. Part of this help may be impossible for you to get due to monetary or time constraints, so, as always, get your nutrition and diet prompts from experts, such as doctors.

Hopefully, this article has given you helpful insights. Or a stepping-stone to better information and understanding of the real dietary needs you have.

Conclusions? Focus on a healthy diet composed of daily superplates, with variety and balance as key elements. 

Sources:
https://www.prevention.com/weight-loss/a20496676/nutrition-myths/
https://www.hsph.harvard.edu/nutritionsource/superfoods/
https://www.bbvaopenmind.com/en/science/research/the-myth-of-superfoods/
https://www.eufic.org/en/healthy-living/article/the-science-behind-superfoods-are-they-really-super
http://topmyths.com/KaleIsItReallyAllThatGreat/