Seed Oils: the good, the bad and the myths

A recent study published in the scientific journal Gut has been making waves across the country with alarming headlines linking seed oils to colon cancer. But what exactly are seed oils? And how much are they causing us harm? We'll take a look at them from a home cook perspective to give you the full answers.

What are seed oils?

Seed oils, as the name suggests, are oils made from seeds including sunflower, corn, canola, soybean, grapeseed and sesame oils, as opposed to oils made from fruits like olive oil, avocado oil or coconut oil.

Seeds oils are made by extracting the natural oils found in seeds by using a combination of high temperatures, extreme pressure or chemical solvents. They are often then further refined in order to make them shelf stable and more suitable for cooking.

Seed oils were popularised in the 1950's when they became incredibly cheap to produce and were marketed as healthier than animal fats like butter or lard - although many of the claims supporting this argument have been disputed. Since the 50's, the presence of industrial seed oils in our foods has sky rocketed, intensified by the accelerating market of ultra-processed foods.

Do seed oils have any health benefits?

Seed oils are high in omega-6s which are essential fatty acids our body needs from food. They are important for the maintenance of hair, skin and bone health, as well as for our metabolism and reproductive health. Less processed seed oils, such as cold-pressed oils, also retain beneficial vitamins and nutrients, although these oils often have a shorter shelf life.

What's the problem with seed oils?

The biggest issue with refined seed oils is that they play an imbalanced role in our diets. Our bodies rely on a balance between omega-6s and omega-3s, which is another essential fatty acid found in foods such as oily fish like salmon or mackerel, walnuts, olive oil, avocado oil and flaxseed. Omega-3s play a crucial role in fighting inflammation in the body as well as improving skin, hair, eye, cardiovascular and brain health.

Studies suggest that an overconsumption of omega-6s found in seed oils can lead to chronic inflammation and a suppressed immune system, especially when they aren't balanced out with those anti-inflammatory omega-3s. Ideally, we should be consuming more omega-3s than omega-6s, but due to the overwhelming presence of seed oils in the diets of average Americans, the scale is tipped majorly towards omega-6s which could be contributing to chronic health problems.

Try these recipes with foods rich in omega-3s!

Do seed oils cause cancer?

The study does not conclude that seed oils cause colon cancer, but they do indicate that diets over-rich in omega-3s, likely due to seed oils in ultra-processed foods, could be contributing to reduced immune responses to tumors, causing them to mutate and grow faster.

Ultimately, reducing your consumption of ultra-processed and 'fast' foods such as store-bought cookies, potato chips, fried foods, and frozen meals, and instead prioritising whole foods including vegetables, fruits, whole grains, and whole food proteins, will likely reduce your overall intake of seed oils and the harmful side effects of too much omega-6. Balancing your diet with foods rich in omega-3s is another great way to keep those omega-6s in check!

One of the biggest problems with ultra-processed food is that they contain unknown amounts of refined oils, processed sugars and additives – all of which contribute to inflammation in the body. These things also make them incredibly addictive, so we eat more than we actually need. Cooking at home is one of the best ways to be more mindful of what we are consuming and how it impacts our health!

What cooking oil should I use at home?

In moderation, seed oils are not bad for you and can be used in your home cooking. You don't need to throw out all your bottles of oil - choosing the best cooking oil really depends on what you are cooking!

For frying foods at high temperatures, seed oils like canola oil work really well as they have a high smoke point and neutral flavors. But fried foods should be eaten in moderation, which will in turn reduce the amount of seed oils you are consuming.

Other seed oils like sesame oil are very versatile but have a strong flavor that works beautifully in stir fries, sauces and marinades. You don't need much of it, so choose a cold-pressed version to get the most health benefits.

If you want to reduce seed oils in your food, try using olive oil, avocado oil, and coconut oil for shallow frying or baking. You can also use animal fats such as ghee or butter, although butter has a low smoking point and shouldn't be used for high heat cooking.

At the end of the day, eating home cooked food will always be healthier than eating ultra-processed foods. So why not start today?