Superfood is a catch-all term that really just refers to a nutritious ingredient packed with antioxidants and vitamins.
We often think of exotic foods such as goji berries and baobab when the phrase comes to mind - but Renée Elliott, founder of Britain's first organic supermarket, Planet Organic, says that some very ordinary ingredients can be just as 'super'.
Her new book, What To Eat And How To Eat It, focuses on the 99 top natural ingredients that she believes everyone should be eating more of, due to their exceptional health benefits.
Here, she shares 10 of them exclusively with FEMAIL readers, and explains just why they are so good for you.
Miso, a fermented soy food, is so nutritious that it is considered a medicinal food. It is a paste made from fermented soybeans, salt and koji (cultured barley or rice).
Miso is a complete protein with all the essential amino acids. It aids digestion and assimilation, it is loaded with lactic-acid bacteria, it is a good source of B vitamins, especially B12, and it strengthens the immune system. But the most interesting fact about miso is that it removes heavy metals, such as radioactive strontium, from the body. This research was started at the Saint Francis Hospital in Nagasaki and later confirmed with the discovery of dipicolonic acid in miso by scientists at Japan's National Cancer Centre.
2: SEED SPROUTS
Sprouting profoundly transforms seeds or beans. Unless you grow your own food and are lucky enough to pick fruit off the tree and veg off the vine to munch on, sprouts are one of the few living foods you will eat.
Because sprouts are still growing in the pot or bag in which you buy them, they are teeming with enzymes and loaded with vitamin C.
Germinating or sprouting seeds creates a huge increase in carotene. It also increases the B vitamins, particularly vitamin B2, B5 and B6. If you can't buy sprouts locally, you can grow your own with a sprouting jar or sprouting kit.
If you want to incorporate sea vegetables into your diet, then start with nori. It has a delicate flavour, is versatile and easy to use.
High in calcium and iron, with vitamin C to help digest it and an impressive amount of iodine in a very absorbable form. Nori is about one-third protein and one-third fibre.
It is high in vitamins A and B, and includes more vitamins than fruits and vegetables. Nori is good for your heart, hair, skin, immune system, digestion, detoxification, teeth, bones, joints, allergies, brain and blood pressure, and it also helps fight cancer.
Sumac is a tangy, lemony spice that comes from the berries of flowering plants that grow in temperate and subtropical regions from North America to East Asia. The spice is often used in Mediterranean and Middle Eastern cooking.
Sumac has a healing reputation that stretches round the globe. It is known as antifungal, anti-inflammatory, antimicrobial, anti-ageing and full of antioxidants.
The National Institutes of Health & Ageing rank it the number one food for neutralising free radicals through antioxidant levels.
An apple a day keeps the doctor away because it has many important health benefits. It's easy to take apples for granted because they are in plentiful supply and seem so ordinary. But they are well worth including regularly in your diet.
There is much research proving that apples provide cardiovascular and antioxidant benefits because of their pectin or water-soluble fibre and their unusual mix of polyphenols (compounds found in plants that have antioxidant properties).
Recent research has focused on this unique balance of polyphenols in apples, some of which are more concentrated in the skin than the pulp. These studies have linked eating apples with a lower risk of asthma and a lower risk of lung cancer.
6: BLACK BEANS
Black beans are also known as black turtle beans or Cuban black beans. They are inexpensive to buy, easy to prepare, versatile to use and tasty to eat.
What's special about black beans is their high levels of antioxidants because of their concentration of anthocyanin, which are pigments that give black and blue fruits, berries and beans their colour and health benefits; the darker the bean, the higher the value of antioxidant.
Black beans are rich in protein, fibre, zinc, copper and molybdenum. Molybdenum, is a key, but less-known mineral needed to form and activate enzymes for detoxification in the body. It is also associated with longevity.
A brilliant fast food, sardines are inexpensive, easy to use and tasty. They are named for the Italian island Sardinia, where large schools of them once swam.
This superfish is loaded with protein and essential omega-3 fats. They are one of the best sources of B12 and are an excellent source of vitamin D. Rich in many nutrients, sardines are particularly good for both your heart and bones.
Sardines are an oily fish at the bottom of the fish food chain, and because they feed on plankton rather than other fish, don't bio-accumulate heavy metals like mercury, which is found in other oily fish. Because of this, sardines are great for kids and pregnant women, and can be eaten frequently.
Tahini is the name for ground sesame seeds, which are possibly the oldest condiment used by people, dating to around 5,000 years old. These tiny seeds are a powerhouse of minerals and are one of the best sources of calcium you can eat.
Tahini made from whole sesame seeds is best, because hulling them removes about 60 per cent of the calcium, and although the calcium in the hull is in a less absorbable form, it is still worth having.
Sesame seeds support bone and general health, and are an alkaline food. Eating tahini is probably better than eating sesame seeds, because when the seeds are crushed, they break down easily and are more absorbable during digestion.
Walnuts, cultivated for thousands of years, are treasured as a food and medicine. Of the three types, black walnuts and white walnuts are native to North America.
Walnuts are 65 per cent great fat. Something particularly interesting about walnuts as a high fat food is that they are beneficial to the almost 25 per cent of American adults with Metabolic Syndrome. The Metabolic Syndrome combination of high blood fats, high blood pressure, low HDL (High Density Lipoprotein) cholesterol plus obesity is actually benefitted from eating walnuts over only a few months.
10: WILD RICE
Distant cousins to Asian rice, wild rice is not a grain but is the seed of marsh grasses from North America. The plants grow in shallow water in slow-moving streams and small lakes.
Cup for cup, wild rice outpunches wholegrain rice because it has less carbohydrate and more nutrients. It has more folate, zinc, and vitamin E than wholegrain rice. It is also high in fibre, magnesium, phosphorus, manganese, vitamin B6 and niacin.
Renée's top tips for eating super ingredients
Eat vegetables whole to get the full benefit of fibre and nutrients. Scrub, don't peel, except maybe celeriac.
2. If you don't cook kale or other dark leaf vegetables, you will not neutralise the oxalic acid and be able to absorb the calcium they provide.
3. Tomato skins contain much of the beneficial carotenoid and flavonols, so leave the skins on and chop or finely chop them.
4. To avoid the goo from okra in stir fries and more delicate dishes, use okay whole, trimming the stem end as little as possible. Trim and slice okra to relate the goo that will thicken gumbo, soups and stews.
5. Fruits are best eaten raw and unpeeled.
6. Soak dried beans overnight in water and vinegar, cook with kombu and at salt or miso after the beans are tender.
7. Reduce your consumption of wheat by trying spelt bread, rye crackers or brown rice noodles.
8. Nuts are at the most nutritious and easy to digest when eaten raw after they are soaked in salted water and then drained, baked at low temps or dehydrated.
9. Eat seeds raw and soaked or sprouted.
10. For a change, replace salt with miso, but don't heat too much or boil in order to retain its beneficial enzymes and microorganisms.