Unless you've been in solitary confinement or exploring the more remote regions of the world, you'll have heard of so-called superfoods. Everyone assumes that eating them is a good thing, but is it? And which foods qualify for the "super" tag?

There is no scientific definition of a superfood according to the British Nutrition Foundation. However, there have been many superfood studies in America and in the UK, and numerous articles and books have been published on the subject. The most-used description of a superfood is: something which has high levels of certain nutrients that have been shown to help tackle disease.

One thing there does seem to be agreement about is that superfoods are of plant origin, in other words they are fruits, nuts, vegetables, leaves, roots or juices.

Every expert has their own particular set of favourite superfoods, but most agree that there are around 25 that deserve the label. Nutritionists at the Baylor University Medical Center in Dallas have compiled a list of wonder foods that includes barley, blueberries, broccoli, Brazil nuts, kefir and Kiwi fruit. Trawling through various reports gave me a long list of foods from acai fruit through algae (ugh!) to wheatgrass, although the ones that were mentioned again and again were fortunately much more ordinary!

Did you know that the top superfood is actually none other than broccoli?

All types of broccoli are packed with dietary fibre, complex carbohydrates, Vitamin C, carotenoids, calcium, folate, potassium and not one but two effective cancer-fighting compounds. To benefit from all this, all you do is eat broccoli three times a week!

Close to all British hearts is a nice cup of tea, and we must know something good because tea is also a superfood - or maybe a superdrink. All teas contain flavinoids and antioxidants, which protect our cells against free radical damage. Tea may also prevent some cancers and osteoporosis, and green tea - which contains polyphenols - could reduce the severity of rheumatoid arthritis.

Other food groups that have been hailed as super include: alliums, berries, brassicas, nuts and wholegrains.

There are some non-plant foods that could qualify for the super sobriquet too: such as eggs, honey, turkey and yogurt.

Of course, eating too much of any one food (whether super or not) isn't a good idea. You can have too much of a good thing; you get a huge dose of some nutrients and nothing of other (equally beneficial) ones. a course in miracles authors with so many things in life, variety is the spice! So choose a wide range of fresh produce rather than processed foods. A good tip is to go for a range of colours, that way you know you'll be getting a mixture of different nutrients.

And go for little and often. In other words, at least five portions of fruit and vegetables a day. Sadly, bingeing on broccoli and blueberries once a week won't really make up for curries, crisps and chocolate at all other times! And the best way to retain all those lovely nutrients is to eat your superfoods raw, or lightly cooked - nobody wants to eat raw Brussels sprouts, do they?