Mushrooms are fascinating things, with their unique woody flavour and the potential to be medicinal or poisonous.

Though they are often thought of as vegetables, mushrooms are actually a fungus, a special type of living organism that has no roots, leaves, flowers or seeds.

So, while you focus on getting your daily dose of fruit and vegetables, do not forget about the world of fungi, which has much nutritional goodness to offer.

It was earlier thought that mushrooms do not have any great nutritional value, but research over the last two decades has shown that mushrooms are a great source of minerals like phosphorus, magnesium, potassium and selenium - nutrients often lacking in our highly processed-food diets.

They are rich in protein and contain contain virtually no fat or cholesterol. They also contain complex carbohydrates, which makes them an ideal food for people who want to keep their blood sugar levels stable.

Dr Georges Halpern, a United States-based doctor and author of Healing Mushrooms, explains that the ability of mushrooms to survive in harsh environments is thought to be due to their pro-active and healthy immune functions. 'Some scientists believe that the anti-pathogenic properties developed by mushrooms as a survival mechanism are precisely what make them valuable to the human immune system,' Dr Halpern has said in his book.

Several other edible mushrooms are reported to have anti-tumour activity and other useful medicinal properties such as regulating blood pressure, blood sugar and inflammation.

Many companies are now developing supplements with mushroom extracts. Some make extravagant claims about mushrooms being able to cure everything from cancer to Aids, but the effect of mushroom supplements is yet to be studied in large-scale clinical trials.

Meanwhile, you can still reap some health benefits by incorporating these mushrooms into your diet.

Shiitake
With their unique smoky taste and slightly chewy texture, Shiitake mushrooms are the most popular mushrooms in the world.

In the 1960s, Japanese scientists observed that people in the shiitake-growing regions of Japan had the lowest rate of cancer.

After running tests on shiitake mushrooms, they were able to isolate a substance they called Lentinan, which is now used as a drug in conjunction with chemotherapy to treat stomach and colorectal cancers in Japan.

As part of a balanced diet, these mushrooms can help boost immunity and are a good source of selenium, iron and vitamin C.

Mushrooms are porous and tend to get soggy if doused in water, so rather than wash them, wipe them with a slightly damp cloth. If you want to store them, the best way to do so is in a paper bag.

They can be eaten grilled, sauteed or added to soups and salads.

A word of caution: People with gout or kidney stones may want to limit or avoid intake of shiitake mushrooms as they are high in purines - substances found in plants that some people cannot break down.

Maitake
Maitake means dancing mushroom in Japanese. In the West, it is called Hen Of The Woods because it grows in clusters of brown, fan-shaped petals that resemble a hen's feathers.

It is popular in Japan as a health tonic. It is now being researched in the West as well to see if it can regulate blood pressure and sugar levels.

The Memorial Sloan-Kettering Cancer Centre in New York is now conducting clinical study of maitake extract in women who had stage I, II or III breast cancer that was surgically removed. The study will determine if maitake extract can stimulate the immune system without causing any side effects or toxicity.

In Singapore, you should be able to find it dried or fresh in speciality Japanese grocery stores.

Button
Commonly found in supermarkets, button mushrooms can be white or brown. They come in various sizes and varieties including the deliciously meaty portobello mushrooms.

These mushrooms are rich in protein. For instance, white button mushrooms contain more protein than kidney beans.

As a group, they are a good source of B vitamins and contain some unsaturated fatty acids.

Oyster
These mushrooms are one of the richest sources of L-Ergothionine, a potent antioxidant. They are also a good source of trace minerals and believed to help maintain cholesterol levels.

Enoki
These delicate mushrooms are a gourmet's dream with their gentle flavour and texture. They can be taken raw in salads and sandwiches or tossed into a soup for a quick, nutritious meal. Enoki mushrooms may help strengthen the immune system and are also said to have anti-cancer properties.

This article was first published in Mind Your Body on Mar 28,2007