All about oils

Olive oil has a long history as "the good oil". One hundred years ago the New Zealand Herald published an article about the European medical profession using olive oil for many childhood diseases, such as measles and scarlet fever.

Its reputation is still well deserved, for different reasons. All types of olive oil contain high levels of monounsaturated fats, which help lower your blood cholesterol and reduce your risk of heart disease when you consume them rather than saturated or trans fats.

Extra virgin has an advantage over other olive oils. When processed correctly it contains the highest levels of antioxidants and polyphenols. Antioxidants appear to protect the body from age-related changes and certain diseases, such as heart disease and some cancers. Of all antioxidants, polyphenols have the most effect.

Despite the health benefits, remember that any oil is 100% fat. If you eat too much of it, you may put on a few extra kilos.

Different grades

• Extra virgin is the highest grade of olive oil. It's made with minimal processing to maintain flavour and aroma. It can't have more than 0.8% acidity and must be fault-free as assessed by an expert panel.
• Virgin is olive oil with minor imperfections and a higher acidity level (up to 2%).
• Pure is refined olive oil with a small amount of virgin oil added, resulting in a milder olive taste.
• Light or extra-light is refined olive oil. It's light in colour and taste. But it's no lighter in fat or kilojoules than other olive oils.

The right oil

When you buy cooking oil you need to consider what you'll use it for - and its taste. You shouldn't use your pricey extra-virgin olive oil for bangers on the barbie.

For everyday cooking or the barbie you'll want a neutral-tasting oil which doesn't mask the flavour of your food. Regular refined olive oil and canola are good choices.

For frying, you'll need oil with a high "smoke point". The smoke point is the temperature to which the oil can be heated before it smokes and discolours. Best oils for frying are blended vegetable oils, sunflower, grapeseed, and peanut oil.

For salads, pasta and stir-fries you may want oil with a distinctive flavour. Most cold-pressed oils (extra-virgin olive, almond and avocado) are good choices. They are also great drizzled on meat, fish, vegetables and salads, or for dipping bread.