Are seed oils good or bad for our health? 

Seed oils are made by extracting oil from the seeds of various plants, such as:

• Sunflower
• Rapeseed (also known as canola oil)
• Sesame
• Grape
• Flax
• Soybean
• Safflower

These oils are versatile and many are budget-friendly choices in the kitchen. Most have a neutral flavour and a high smoke point, which means they can handle high cooking temperatures – like when you’re frying or roasting – without breaking down or producing unpleasant flavours or potentially harmful compounds. This makes them a safer and more reliable option for everyday cooking.

A particular benefit of seed oils is that they are high in unsaturated fat – the type we should eat more of – and low in saturated fat, which we should eat less of. This makes them a healthier alternative to animal fats like butter and ghee.

Importantly, seed oils provide essential omega-6 fats, which our bodies can’t make so we need them from our diet. These fats support healthy skin, and help build and maintain our cells.

Seed oils and inflammation

You may have seen claims that seed oils cause inflammation. This is mainly because they contain an omega-6 fat called linoleic acid, which can be converted in small amounts into another fat called arachidonic acid – a compound involved in the body’s inflammatory response.

Some people worry that eating too much omega-6 could compete with omega-3 fats, which support heart and brain health, and have anti-inflammatory properties. The concern is that both fats share some pathways in the body, so too much omega-6 may reduce the impact of omega-3s and promote inflammation.

But research doesn’t support this idea. In fact, studies show that people who eat more linoleic acid – the type found in seed oils – often have lower levels of inflammatory markers in the body. Instead of cutting back on omega-6, it’s more important to focus on getting enough omega-3s in your diet by eating oily fish (like salmon), green leafy vegetables (like brussels sprouts) and nuts (like walnuts).

What about cancer risk?

When it comes to cancer, there’s no strong evidence to show that seed oils increase risk. What matters most is your overall diet – we recommend you eat a diet rich in fruit, vegetables, wholegrains, pulses, nuts, seeds and lean proteins like fish and chicken to support your long-term health and reduce cancer risk.

Seed oils in processed foods

Seed oils can be found in ultra-processed products like:

• shop-bought salad dressings
• mayonnaise
• cakes
• biscuits
• crisps
• sweet and savoury pastries

These foods are typically high in salt and sugar, and low in fibre, vitamins and minerals – not ideal for our health.

In fast food restaurants, oils may be reheated multiple times at very high temperatures, which can produce potentially harmful compounds. Most of us don’t cook like that at home.

But it’s important to remember – seed oils themselves aren’t the problem. The real issue is the overall quality of the processed foods that contain them. It’s these foods that are linked to a higher risk of obesity, heart disease, type 2 diabetes and some cancers.

That’s why one of our Cancer Prevention Recommendations is to limit fast food and processed foods that are high in saturated fat, salt and sugar.

So, should I avoid seed oils?

Not at all – and there’s no need to fear them. Seed oils can be part of a healthy, balanced diet. They’re low in saturated fat, provide essential omega-6 fats and offer useful nutrients like vitamins E and K, which support immune health and normal blood clotting.

As with all fats, it’s about using them wisely. They’re high in calories, so stick to small amounts – a teaspoon or a light spray is often all you need. Seed oils are versatile in the kitchen, perfect for roasting, stir-fries, baking, homemade salad dressings or as a healthier alternative to butter or ghee.