| Potentially edible!|
Media organisations often publish lists of supposed "Superfoods" to attract clicks. The term "Superfood" is a marketing ploy and not a term used by qualified dietitians or scientists. Often these foods are based on a kernel of truth and therefore fall somewhere on the spectrum between "real science" and woo. Since none of them are dangerous (unless Third World globalization has compromised their authenticity or purity) and since
all some of them can be tasty, adding them to your diet can't hurt your body (at least in moderation). If they turn out more "woo" than "science", no medical harm done. And if they turn out to be really extra-special healthy for you, all the better.
Many foods are claimed to be "super" because of alleged or actual high-levels of antioxidants. Consuming too many antioxidants (e.g. in pill form or in fad diets) might actually be bad for you because muscle-building requires some oxidation.
Of course, these have a mysterious tendency toward the exotic, obscure, or highly perishable in comparison to equally nourishing and pleasant foodstuffs of lesser celebrity, which means they're usually only available at great expense and/or from a tiny number of merchants… Who are all too happy to let you pay through the nose for this “privilege,” and when these foodstuffs are a load-bearing pillar in the diets of people in certain low-income regions, the surge in interest can have cataclysmic impacts on their main food supply.
Coffee is usually not considered a superfood (although…) even though it is high in antioxidants,, probably because there is no money to be made from additional marketing. A large epidemiology study found that drinking more than 2 cups per day of coffee increases life expectancy and is protective against several diseases.
List of some common "Superfoods" and their spurious claims
- Açaí berries (Euterpe oleracea) — marketed as a dietary supplement for weight loss but with no convincing evidence. Subject of many internet scams.
- Apples (Malus domestica) — An apple a day keeps the doctor away, or so they say. The seeds contain a small amount of laetrile for those who believe in cancer preventative woo (and cyanide for those who don't.) The apples themselves are full of fiber and keep you "regular".
- Apple cider vinegar — This acid is used by people to treat "body pH imbalance" because the body becomes too acidic. Yes, they actually believe that taking vinegar will increase the body pH level, rather than lower it like any normal acid would.
- Blueberries (Vaccinium spp.) and blackberries (Rubus spp.) — make boring yogurt tolerable and they anti-oxidize you at the same time, for whatever that's worth.
- Brewers yeast (and its derivatives like Vegemite and Marmite) — a B-complex vitamin cocktail. Good for whatever you heard B vitamins are good for. Brain food and who knows what else.
- Chia seeds (Salvia hispanica) — Once known for their amazing ability to spawn an afro on any known creature, they are now being hailed as the low calorie super nutrient you never knew your body needs to survive. 
- Chocolate (Theobroma cacao) — food of the gods. In its raw form Cacao (usually in the form of 'nibs') and processed dark chocolate are excellent anti-oxidants. There is some suggestion that they can act like aspirin to keep plaque forming in the blood, that they might stimulate the brain, and that sucking on dark chocolate can soothe an aching throat, raw from coughing. And it's so close to that wonderful panacea hemp! And come on, it's chocolate. (Dear Americans, milk chocolate however has lots of sugar and very little cacao, so it isn't a wonder food - learn to like the dark stuff!)
- Cinnamon, by which we mean the common commercial Cinnamomum cassia, not the "true" Cinnamomum verum that food snobs use — can help reduce blood sugar peaks. Or not. It makes lots of things more yummy, and if it helps to prevent the onset of diet-based diabetes so much the better.
- Cranberries (Vaccinium spp.) — commonly hailed as an effective way to avoid urinary tract infections. According to a recent clinical review however, you'd have to eat about 45,000 calories' worth of cranberries every six months to get a 1 in 12 chance of avoiding an infection. Not exactly practical, unlike the 95% efficacy of taking antibiotics.
- Curry (turmeric, Curcuma longa, in particular) — supposed to be a preventative for cancer and Alzheimer's.
- Ginger (Zingiber officinale) — it is claimed that ginger can combat motion sickness and nausea (Ginger Ale, anyone?), and could help relieve the pain associated with "that time of the month" .
- Goji berries or Chinese wolfberries (Lycium barbarum) — Supposedly great because of its high protein content for a fruit, filled with iron/vitamin A, and antioxidants like zeaxanthin. Can also work as a weight loss helper due to unpleasant (sometimes severe) stomach cramps after consumption.
- Green tea (Camellia sinensis) — It's a
ritual designed to make you relaxsource of the psychoactive amino acid Theanine, and it too can anti-oxidize you.
- Jiaogulan (Gynostemma pentaphyllum) — Can slow down your aging, inhibit cancer growth, and anti-oxidize you.
- Kombucha tea — is green tea fermented with bacteria and yeast. It has both anti-oxidant and probiotic properties but these can be found cheaper (and far more pleasant) in many other foods 
- Moringa (Moringa oleifera) — It's loaded with vitamins and minerals, and it too can anti-oxidize you.
- Oysters — supposed to increase your sperm count, improve libido, enlarge your weenie, etc.[more detail please]
- Pomegranate juice (Punica granatum) — You know it's heart-healthy because they sell it with cute little healthy-heart icons on the bottles.
- Quinoa — vegan superfood, demand for which is destroying the ecosystem, and the human population in Bolivia. 
- Shiitake mushrooms (Lentinula edodes) — You can just taste the tingle of anti-oxidant woo cleansing your body of toxins!
- Walnuts (Juglans spp.) — lots of fiber and protein, and it turns out they might help lower the icky bad cholesterols.
Some lists with other wooish/scientific-ish super foods
- A rather awesome analysis of superfoods from Australian TV show, The Checkout
- Stop Telling Me How To Eat To Cure My Incurable Disease (And Other Things People Without Medical Degrees Say To The Chronically Ill), on xoJane
- Why There's No Such Thing as a Superfood in Outside, 14-Nov,2014
- For athletes, antioxidant pills may not help performance: Some supplements can blunt the positive effects of exercise training by Laura Beil, Science News (February 24, 2015).
- Superfood of the Week: Coffee
- [http://www.webmd.com/diet/the-buzz-on-coffee The Buzz on Coffee] by Kathleen M. Zelman & Brunilda Nazario (May 07, 2008) WebMD.
- Coffee gives jolt to life span
- Coffee reveals itself as an unlikely elixir: From liver disease to diabetes, coffee compounds protect against an array of health conditions by Nathan Seppa (12:02pm, September 18, 2015) Science News.
- Oprah is coming after bad Internet marketers
- This saying originated during Prohibition. Most of the apples sold prior to Prohibition were used to make hard cider. When this was no longer legal, apple growers had to come up with another reason for consumers to buy their fruit, and latched on to the apple's alleged health benefits.
- Altmedicine.about.com article on Apple Cider Vinegar
- Brewer's yeast, on the University of Maryland's Complementary and Alternative Medicine web area
- With clickbait to match!
- "Cinnamon and Blood Sugar," Pennsylvania State University Extension
- Cranberry, the alt-med zombie
- Turmeric contains curcumin which is an anti-oxidant.
- Why? Who knows, but maybe a clinical trial will reveal more information.
- 8 Goji Berry Facts
- Goji Berry: Basic Information and Traditional Uses
- Beware! Goji Berries
- Jiaogulan (Gynostemma pentaphyllum) Health Benefits & Information
- Moringa Oleifera Health Benefits & Information
- http://www.whfoods.com/genpage.php?dbid=122&tname=foodspice typical woo site
- Could eating WALNUTS be the key to good heart health?, on The Daily Mail