Seed oils are a highly contentious issue in the nutrition world right now. Some ‘experts’ tell you they’re perfectly healthy, whilst others will tell you they’re harmful and the cause of many chronic diseases. Is this a worry for you? I’m still weighing up the arguments, but here are some of my thoughts so far…
Seed oils were not part of the human diet at all until the early 1900s, when the highly toxic cottonseed oil (a byproduct of the cotton industry) was found to be edible after undergoing several industrial processes.
Industrial seed oils include canola (rapeseed), corn, cottonseed, soybean, sunflower, safflower, grapeseed, rice bran, peanut, sesame and flaxseed oil.
Unlike olives and avocados, these seeds do not easily give up their oils, hence the industrial processing required to make them. Sometimes you’ll see ‘cold-pressed’ on the labels - this means they’ve been treated a bit kinder, but it’s not a very efficient process - a lot of oil gets left behind in the seeds.
Seed oils contain high levels of omega-6 fatty acids and little, if any, omega-3 fatty acids. This affects the ratio of omega 6 to 3 in the body when significant quantities are consumed. The optimal ratio is thought to be around 1:1 (based on ancestral type diets) but currently, where seeds oils and ultra-processed foods make up large quantities of our diets, that ratio is more like 10:1 or higher (in favour of omega-6). Omega-6 is generally inflammatory, whilst omega-3 is generally anti-inflammatory.
Seeds oils become oxidised at high temperatures, meaning they produce ‘free-radicals’ that can cause harm to our cells and tissues.
Seed oils are very low in nutrients. They contain no fat soluble vitamins such as A, D and K2 which are essential for our health. In contrast, the more traditional fats - butter, lard, tallow, coconut oil - do contain these essential nutrients.
When you dig into the definition of ultra-processed foods, seed oils actually don’t meet the criteria as they are considered a standard ingredient most people would have in their kitchen cupboards. However, here is a quote from Ultra-Processed People by Chris van Tulleken on how seed oils are created…
“So, manufacturers refine the oil by heating, use phosphoric acid to remove any gums and waxes, neutralise it with caustic soda, bleach it with a bentonite clay, and finally deodorise it using high-pressure steam”
With that in mind, would you consider these oils to be ultra-processed? Or a safe and even healthy kitchen ingredient?
Bear in mind also that these seed oils are incredibly cheap to make, are hugely profitable for the food industry and make up a large portion of the ingredients in foods that are considered to be ultra-processed. The science is now overwhelmingly clear that ultra-processed foods are harmful to health. So much so, that they’re now saying UPFs are the number one cause of disease and early death, even above smoking, worldwide.
Want to dive into this subject a bit further? Understand what’s really going on with ultra-processed foods and why we can’t stop eating them? I’m running a little workshop in Belper, at Eartharmony, on Monday 31st March, 6-8pm. Tickets are just £20 each. You’ll come away feeling informed, empowered and energised! Tickets available here.
Hope to see you there!
Lucy x
