Seed Oils: so bad?

Seed oils have been getting a bad rap lately, and many people are avoiding them at all costs. But how can it be that seeds are considered a very healthy food, but seed oils are bad for our health? Let’s do a deeper dive into this question.

Seed oils are generally poly-unsaturated fatty acids, or PUFAs. We need a moment of biochemistry to understand what that means.

An unsaturated fat is one that contains some double bonds between the carbon atoms along its backbone. These bonds are not linked up to as many hydrogen atoms as they could be, so the molecule is not  “saturated” with hydrogen atoms. These double bonds make the fat reactive: it can interact with other chemicals it encounters.

A mono-unsaturated fat has just one such double bond, and a polyunsaturated fat (PUFA) has several of them. The more double bonds, the more reactive the oil is, and the more carefully it should be handled and used.

These oils should be stored away from light and heat, in dark bottles in the fridge. Many of these, such as flax and hemp seed oils, should not be heated. Olive and avocado oils, which are fruit flesh oils, can be used in cooking.

Most natural, minimally processed PUFAs are high in omega 3 and omega 6 fats, both of which make the oils very fluid and are healthy for us.

A saturated fat, in contrast, has a hydrogen atom occupying every

possible bond, so it doesn’t have the capacity to react with other

chemicals: it is a stable molecule. This saturated structure also makes

it more solid. The more stable a molecule is, the more it can

withstand heating, so you might think that saturated fats would be

the best to cook with. Indeed, butter, ghee, lard and beef tallow are all making a comeback in health food stores. However, saturated fats come with their own health challenges. Studies have shown that diets higher in saturated fats are associated with increased cardio-vascular disease and some cancers. This was the main push against consuming red meats in the past: the saturated fat in meat seems to have pro-inflammatory effects.

And just as we store toxins in our fat cells, animals do too, so if you do eat animal fats, choose organic.

Over 100 studies have shown that consumption of several plant sourced oils is associated with better health than saturated fats. These include canola, olive, and soybean oils. None of these oils is made up of just one type of fat: they all contain different proportions of fats, saturated and unsaturated, which are greatly affected by processing methods.

But the production and processing of oils in the industrialised world differs considerably from how it was done in our great-grandparents’ days.

Oils used to be extracted just by crushing the seeds and catching the oil, but nowadays only extra-virgin, cold-pressed oils are extracted that way. Such oils retain their healthy structure and antioxidant content.

After that first extraction, the remaining plant matter used to be returned to the land as compost, but these days hexane solvents and heat are used to pull more oil out of it. Then the hexane has to be removed from

the oil before it is consumed, because high levels of this contaminant are associated with health problems. In addition, the chemical changes triggered by heat have permanent adverse effects on the oil molecules and damage the oil’s natural antioxidants.

Oils are then bleached and deodorised using even more chemicals. The deodorising process changes some of the omega 3 fats in the oils to trans fats: the kinds of fats that have been banned in many countries because of their adverse effects on health.

Processed oils are often packaged in clear plastic bottles, to show

off their light colour to customers, but this leaves the oils exposed to damaging sunlight. Another case of the product’s appearance being put before the consumers’ health.

Health trials have mainly been conducted on industrially processed seed oils, and yet those oils still did better than animal fats when it comes to heart health.

This whole confusing situation has led to the emergence of “gourmet” seed oils, such as the extra virgin cold pressed canola oil that has been

catching on, found at some specialty shops and farmers’ markets.

Canola is a member of the brassica (broccoli) family. It is a crop suited to northern climates like Canada and the UK. Canola seeds produce a naturally deep golden oil with a distinctive flavour. Unfortunately most canola is not organic, and producers believe the consumer expects a light coloured, clear oil with no flavour. Therefore most canola is heavily treated to bleach and deodorise it.

If we could guarantee our seed oils: canola, sesame, sunflower and the like, are organic, first-pressed, unbleached and untreated with chemical solvents, these would be healthy choices. But most seed oils on the market are heavily chemically treated, and these are also the ones commonly found in all processed foods, and used in restaurants.

We would argue that whatever form of fat you choose to use, look for organic sources, in their most natural, least processed form. It is so often not the substance that is the problem, but rather what we have done to it! If you use animal fats, including butter, try to use organic ones to avoid the hormones and antibiotics used in raising non-organically farmed animals. And don’t believe everything you read on social media about seed oils!