THE TRUTH ABOUT SEED OILS

What the science is currently saying

Few topics in the world of nutrition spark as much heated debate as seed oils. Found in everything from salad dressings to chocolate, they are very much a staple in our modern diet and a magnet for controversy within the wellness community. 

As someone who has spent more time than they care to admit sifting through the fierce world of online nutrition debates, I’ve heard it all. From claims that seed oils are the root cause of chronic inflammation and weight gain, to advice like rubbing canola oil on your belly to help lose that same weight and regulate your digestive system….(whoever would have thought the key to your digestive system was on the outside of it this whole time!) With all of these conflicting sources of information, no wonder it can get confusing and overwhelming out there. In this post, we’ll take a look at what the science actually says, cut through the misinformation, and figure out how we can make smarter, simpler choices to be the healthiest version of ourselves without overcomplication. As with everything in life, work harder not smarter! 

First of all, what are seed oils?

Seed oils are the cooking oils derived from seeds, the most common ones you will come across in NZ are: 

• Canola or rapeseed oil
• Soybean oil
• Sunflower oil
• Rice Bran oils

Oil can be extracted from seeds using either mechanical or chemical methods. Have you ever heard the term “cold-pressed”? That’s an example of mechanical extraction.

Put simply: mechanical extraction involves physically pressing or squeezing the seeds to release the oil. It’s a clean, straightforward process and doesn’t involve any chemicals. However, the downside for the producer is that it doesn’t remove all the oil—some is left behind in the seed material, making it the less effective method of extracting the oil.

The alternative? Chemical extraction. With this method, the seeds are cleaned and then ground and crushed to increase their surface area. The seeds are then exposed to a solvent, usually hexane, which dissolves the remaining oil. This oil-solvent mixture is then heated so the solvent can be separated and recovered through distillation, leaving behind the extracted oil. 

Why the Controversy?

There are two main concerns that are often brought up on the topic of seed oils. The first and most common one you may hear is that the Omega 6 content of seed oils causes inflammation in our bodies. Lets take a closer look at that. Omega 6 is an essential fatty acid, meaning our bodies cannot make their own and must be sourced from our diet. Its job is to maintain cell member structure and brain function. Many people claim that Omega 6 can cause inflation in the body and there may be some truth to that in the form of omega 3 -6 ratio but we are talking about seed oils and their omega 6.  The most common and abundant omega 6 found in seeds oils is called Linoleic acid. Linoleic acid helps play an important role in the production of other fats that in turn work to bring down inflammation. As a result, a diet high in linoleic acid is proven to lower inflammation and reduce LDL cholesterol (the bad kind). We have found that replacing saturated fat in your diet with a seed oils can massively lower your risk of coronary artery disease and even type 2 diabetes.  Sounds great, right? Well remember that too much of a good thing is still too much, so I wouldn’t recommend cooking in a excess oil and deep frying every Mars bar you see. 

The other main concern relates to that gas we mentioned before, Hexane. Hexane is objectively bad for us, and even though hexane evaporates quickly, prolonged exposure can cause harm and unlike everything else, nobody is debating that. But the toxicity is dose dependent, and it is for this reason that all chemically extracted seed oils must go through several methods of vigorous testing. Although some trace levels can be left over, it isn’t enough to damage our health, and if you had any concern then feel free to stick to cold pressed oils. 

The Bottom Line

Seed oils, especially those high in linoleic acid have gotten a bad rap, but a lot of the fear comes from misunderstanding or outdated info. The truth is, when used in moderation, they are actually good for your health. They support brain function, reduce inflammation and lower your risk of things like heart disease and type 2 diabetes.

As for the chemical concerns like hexane, the amounts detected in final product are negligible and the products are heavily regulated. Though as mentioned above, if you’re still not comfortable, there’s always the option of cold-pressed oils.

So, while we navigate our way through this cost-of-living crisis, it’s important not to make things harder for ourselves by vilifying food that’s just as healthy as olive oil, and often half the price!

What Does the Science Say – a summary

• Omega-6 isn’t inherently harmful — it’s about balance with omega-3.
• Large population studies show heart-health benefits when replacing saturated fat with seed oils.