What do labels like “cold-pressed”, “high-oleic”, and “light” actually mean?

Oil bottles are full of terms that sound healthy but are often misunderstood.

“Cold-pressed refers to how the oil is extracted, without heat or chemicals,” says Sekula. “This helps retain flavour and antioxidants but usually makes the oil more expensive.”

With olive oil, labels such as “extra virgin” and “virgin” relate to quality, acidity levels and extraction methods, which also influence flavour.

Another term appearing more often on shelves is “high-oleic”. Henderson explains this refers to oils produced to contain higher levels of oleic acid, a monounsaturated fat that is more stable at higher cooking temperatures.

“High-oleic versions of sunflower and rapeseed oils are better suited to high-temperature cooking than standard versions,” Henderson says, noting the term is still relatively new in New Zealand and only appears on a small number of products.

Not all labels signal improved nutrition. Henderson says “light” oil refers to colour or flavour rather than calorie or fat content.

What actually matters for health

According to Sekula, the type of fat matters most for long-term health.

“Oils higher in mono and polyunsaturated fats and lower in saturated fats, such as olive oil, support heart health when used regularly,” she says.

Smoke point affects cooking performance and flavour, but becomes more important only when oils are used incorrectly or repeatedly overheated.

How popular supermarket oils compare

Olive oil

A standout for health and versatility. Henderson says extra virgin olive oil is rich in monounsaturated fats and antioxidants, with evidence showing heart health benefits when consumed daily. It works across most cooking methods and cold uses, while regular olive oil remains a more affordable everyday option.

Canola oil (rapeseed oil)

Known internationally as rapeseed oil, this is one of the strongest budget performers in New Zealand. “Canola oil is one of the most affordable oils in New Zealand and performs well nutritionally,” Henderson says. It is low in saturated fat, contains plant-based omega-3 fats and has a neutral flavour suited to everyday cooking.

Avocado oil

High in monounsaturated fats and nutritionally similar to olive oil, but significantly more expensive. For most households, it offers a limited advantage over cheaper alternatives.

Sunflower oil

Standard sunflower oil is higher in omega-6 fats. Sekula says high-oleic versions are more stable at higher temperatures and nutritionally closer to olive or canola oil, though these products remain relatively uncommon on New Zealand supermarket shelves.

Rice bran oil

Rice bran oil is commonly used for high-heat cooking because of its relatively high smoke point and neutral flavour. It contains a mix of monounsaturated and polyunsaturated fats and is often chosen for frying and roasting where flavour neutrality is preferred.

While it performs well from a cooking perspective, it does not have the same level of public health research behind it as olive oil. Nutritionally, it sits closer to everyday neutral oils such as canola than to saturated-fat-heavy options like coconut oil, making it a practical but not standout choice.

Peanut oil

Peanut oil is commonly used in stir-frying and deep frying because of its relatively high smoke point and mild, slightly nutty flavour. It contains a mix of monounsaturated and polyunsaturated fats and is often chosen for Asian-style cooking where heat tolerance and neutral flavour are useful.

From a nutrition perspective, peanut oil does not offer the same antioxidant profile as extra virgin olive oil and is usually more expensive than everyday neutral oils such as canola. It can work well for specific cooking applications, but it is not essential as a household staple.

People with peanut allergies should avoid peanut oil unless the product is clearly labelled as highly refined and allergen-free, and even then, caution is recommended, particularly when cooking for others.

Coconut oil

Despite its popularity, Henderson says it should not be treated as an everyday cooking oil. “It is rich in saturated fat and is best used occasionally rather than daily.”

Vegetable oil blends

These vary widely in composition and quality. Some are suitable for cooking, but the generic label can make it difficult to assess nutritional value.

How long oils last in your cupboard

Most cooking oils should be used within six to 12 months once opened, depending on storage conditions and oil type.

Sekula says oils should be stored away from heat, light and air, ideally in a pantry or cupboard rather than on the bench. Signs of rancidity include stale, bitter or paint-like smells or flavours.

Best oils for cold use only

Extra virgin olive oil is well suited to dressings and finishing, while toasted sesame oil is best used sparingly for flavour rather than high-heat cooking, Henderson says. Nut and seed oils also work well cold but tend to be more expensive.

The one rule worth remembering

“There is no single perfect oil,” Sekula says. “Use oils high in mono and polyunsaturated fats most often, match the oil to how you’re cooking and use it sparingly.”

For most Kiwi kitchens, olive oil and canola oil together cover almost every everyday cooking need without blowing the grocery budget.

Herald contributor Nikki Birrell has worked in food and travel publishing for nearly 20 years. From managing your kitchen to cutting costs, she’s shared some helpful advice recently, including how to prep your barbecue for summer grilling, gourmet hacks for elevating budget ingredients and what toppings to choose for different crackers.