But the term superfood is not recognized clinically nor readily acknowledged among nutrition experts and the evidence for supplementation has now moved in favor of balanced diets over popping pills of single nutrients.
Experts maintain that the right diet can not only control weight, but also help to keep diseases at bay by fighting the stressors our bodies encounter on a regular basis, including lack of sleep, poor diet, lack of exercise and general stress at work. These stressors can reduce our physical and mental performance and even lead to chronic diseases such as heart failure or diabetes.
So rather than which foods are "super," we asked experts which foods are useful to include as part of a balanced diet, to keep our bodies fit and healthy.
Be it blueberries, strawberries, cranberries or others, the berries are the most researched food group in terms of health benefits to both mind and body. Cranberries are recognized in fighting urinary tract infections and blueberries have been found to protect the brain from stress and improve cognitive factors such as memory. "Blueberries have been shown to even lower blood pressure," says Joy Dubost, spokesperson for the U.S. Academy of Nutrition and Dietetics
Scientists at Tufts University, including Barbara Shukitt-Hale, have been researching the cognitive benefits of consuming berries on a regular basis. "The berries are the top ... they seem to have a multitude of neuronal benefits," she says, referring to her team's findings of blueberries improving the communication and signaling between nerve cells. "We've shown that blueberries improve your memory."
So how much is enough? "A cup a day," suggests Shukitt-Hale.
The actual components improving brain functions such as memory are not yet understood but trials in animals, and more recently humans, have shown a link between the two and the berries are known to be packed full of antioxidants and anti-inflammatory compounds, which can protect against stressors such as aging, smoking, or consumption of high-fat diets. But eating them doesn't offset the impact of a poor overall diet "They're not going to make you superhuman," warns Shukkitt-Hale.
Research into the benefits of berries in the fight against cardiovascular conditions has been led by Eric Rimm, professor of epidemiology and nutrition at the Harvard School of Public Health. "There really is a strong association with decrease in blood pressure, heart disease and stroke," he says. The anti-inflammatory compounds in the berries are thought to fight the inflammation caused by daily stress.
In research conducted with NASA berries have also shown protection in rats against radiation damage in space, according to Shukitt-Hale.
Whilst this food group as a whole provides benefits to your health, the team at Tufts have identified the perfect storm of compounds inside the walnut. As well as improving memory, they have also been shown to improve bodily movement and control. According to Shukitt-Hale, the walnut contains a multitude of compounds including polyphenols, melatonin, folate, and omega-3. "Systematically they all work together," she says. If these compounds were consumed in high doses individually, they could be toxic, but "there's something about the matrix that works together to prevent being toxic."
Dubost points out the benefits of nuts in general. "It's all about healthier oils in the body to help protect against heart disease," says Dubost, although she warns of caloric intake if consuming too many nuts. "[there's a] high level of fat in them."
The presence of omega-3 fatty acids can help offset deficiencies in those who dislike eating fish as the version found in the nut can be converted within the body. "If you hate fish, that fatty acid can help substitute for that," adds Rimm who believes eating the right oils should be a message made loud and clear. "A high fat diet is not bad, you just need the right fats."
"The fungal kingdom is amazing," says Dubost, whose previous research explored the beneficial antioxidants found in mushrooms ranging from the more common button mushroom, to Portobello, shiitake and oyster mushrooms.
"A lot of people don't think of mushrooms as being nutritious," she says. "But they're really nutrient-dense." Dubost is keen to stress the importance of compounds other than essential nutrients, such as protein and vitamins, and to highlight those such as antioxidants, anti-inflammatory compounds and others which aid with gene regulation in the body. Mushrooms have been found to be high in potassium, B-vitamins, and antioxidants such as ergothioneine, as well as low in calories, according to Dubost.
However, research into this food group is in its early stages meaning long-term studies of their impact are yet to take place.
Hidden depths of wholegrain
Wholegrain has long been advocated as a component of a healthy diet but its often thought of as a source of fiber, Rimm is keen to point out a lesser appreciated component, in the form lignin.
Lignin is the tough component found in grains which can be broken down by gut bacteria to produce polyphenols with anti-inflammatory properties. This in turn can aid towards lowering blood pressure. The greater the grain, the greater the benefit. "The more grain you can physically see in the bread, the better," says Rimm.
"A lot of studies have been initiated trying to find something wrong with coffee," says Rimm, who explains that it has instead been found to be linked to lower rates of diabetes
The polyphenol in coffee -- chlorogenic acid -- is a strong antioxidant. "It's likely to be influencing insulin," says Rimm, who thinks its protective effects against diabetes stem from this influence, aiding the body's ability to absorb glucose more readily and put less stress on the pancreas.
Of course, coffee doesn't agree with everyone and causes side effects such as headaches and insomnia in some people.
The big picture
At the core of it all is regularity, as these nutrients are quickly cleared out of the body once consumed. But equally crucial is the variation as highlighted by all three experts.
"With superfoods, people want exotic, but many products in your back yard will be beneficial," says Dubost. "It's all about major food groups and a variety."
Or as Shukett-Hale puts it, "It's not about should I eat blueberries or mushrooms, it's about, 'should I eat blueberries or chips?'"
Not even a food claiming to have superpowers can compensate for a bad diet alongside it.