National Chip Week will soon be upon us, providing kids with ample excuse to drag their parents into every known junk-food outlet.

However, the potato itself, minus excess salt and fat, is a most useful and nutritious vegetable worthy of a closer look.

There are thousands of different spud varieties.

First cultivated by the ancient Incas more than 4,000 years ago, they were introduced to Europeans by Spanish conquistadors in the 16th Century.

Irish farmers survived on little else for centuries, until their potato crops were completely destroyed by a fungus in 1845.

More than a million people died of starvation or emigrated because of Ireland's over-reliance on potatoes.

Nowadays, the average person eats their way through approximately 100kg of potatoes per year.

Whatever your favourite variety, be it King Edward, Desiree or Maris Piper, potatoes are high in carbohydrates and fibre.

They also contain quality protein, although the content per potato is relatively small.

Virtually fat-free, potatoes are an excellent aid to slimming, as long as you don't smother them with lashings of butter, sour cream or cheese.

Potatoes are also a useful source of vitamin C, the Bcomplex vitamins and iron. And think potato, think potassium. This mineral works with sodium to regulate water balance, nerve and muscle impulses.

The more sodium is eaten, the more potassium is required to maintain good health.

Adding potassium to your diet can lower blood pressure by counteracting some of the effects of high salt intake.

Our prehistoric ancestors thrived on high-potassium, low-sodium foods such as tubers, roots, fruits, nuts, grains and seeds.

Modern humans tend to eat around 75 per cent less potassium than their forebears and add insult to injury by liberally sprinkling their chips with salt an ideal recipe for high blood pressure, a major cause of strokes.

Are there any downsides to the potato? You should avoid buying heavily sprouted or shrivelled ones or those with a green colouring.

The discolouration is caused by exposure to natural or artificial light.

The greenish bits contain the chemical solanine, which is toxic in large amounts.

Potatoes belong to the nightshade family and people suffering from arthritis may experience less pain and discomfort if they avoid potatoes as well as tomatoes, peppers and aubergines.

Although delicious, overcooked or mashed potatoes are so starchy they may upset blood sugar levels and make you sleepy.

They are best eaten baked in their skins, steamed orboiled in a minimal amount of water.

If you want to have your chips and eat them, try home-made fries. Cut an organic potato into slices, then into sticks, retaining the skin.

Brush with olive oil and soy sauce and bake in a preheated oven (220C) for 15 minutes a much healthier and tastier alternative to ordinary deep-fried chips.