At our recent Lifestyle Seminar we spoke about a number of ‘unobvious’ things that make our diet unhealthy. By unobvious I mean things that people wouldn’t necessarily deem as unhealthy.
It is interesting
that there are many people that think that seed oils, like sunflower oil for
example, are good for you. However, it is not surprising because we are
constantly bombarded with health claims of these oils because of their
low saturated fat content and high in polyunsaturated fat content. Of course
most people don’t question whether this is true or not. You certainly wouldn’t
look at a sunflower and think of it as unhealthy or question how healthy vegetables are.
So, how exactly are seed oils, like sunflower and vegetable oils made?
Firstly the main
thing to remember is that to obtain oil from any such seed it has to be highly processed using industrial
techniques in large factories because there is no simple or natural way to extract these oils from seeds. Unlike olive oil which is cold pressed to retrieve its oil. In fact seed oils are a fairly new addition to our diet that only
appeared in the early 1900’s after the invention of industrial processing
techniques (factories).
Ok, so a bit of
processing won’t hurt you say. Really? Well let me tell you what kind if
processing we’re talking about.
We’re talking about heating the seeds at
unnaturally high temperatures so that they oxidise (go rancid) then, process
with a petroleum solvent to extract the oils, a chemical called hexane, (they get washed in this chemical for 70 minutes. This chemical is also used in the formulation of glues for shoes, leather and roofing!). Then acid is added to remove any nasty wax solids that were formed during initial processing. The oil is then bleached to improve the colour and finally the oil is deodorised to get rid of the terrible smell caused by the oxidation process (the
rancidity). To see how seed oil (Canola) is made see figure 1 below and watch this video. (However don’t be
fooled by the ‘health’ claim at the beginning! Canola oil is made from a hybrid
seed made from rapeseed. There is no such thing as a canola seed!).
Fig. 1 How Canola Oil is processed
Now we could stop
there and that should hopefully be enough to make you think twice before eating
this stuff. But there’s more.
Polyunsaturated Fats - PUFA's
Vegetable oil, (wrongly called vegetable oil because it doesn’t come from vegetables but from seeds), is highly unstable. This means that when it’s exposed to air, light or heat it starts to oxidise or go rancid. The seeds themselves have naturally built in antioxidants but these antioxidants are destroyed during the processing. So it is very likely that even before you buy the oil and bring it home form the store, it has already started to go rancid just by sitting on the shelves, especially since it is packaged in clear plastic bottles. To further the problem, when the oil is heated it continues to oxidise so that any antioxidants that were spared during the first process have definitely been destroyed by now. When we ingest the oil it continues to oxidise in our bodies. The instability causes free radicals to begin to destroy the cell membranes and cause cell mutations. This results in inflammation and has been linked with many diseases such as cancer, heart disease and endometriosis.
The main cause of
the instability in seed oils is PUFA’s, Poly Unsaturated Fatty Acids, also know
as Omega-6 fatty acids.
You may have
heard about these as being very good for you. The truth is they are good for you
but in small proportions. The body needs these in equal amounts to Omega-3
fatty acids (ratio of 1:1) which are also essential for good health. However,
in today’s Western diet we are having a ratio of about 16:1. Way too many of
these Omega-6 fatty acids have entered our diet and thrown things out of
balance.
Hydrogenation
To add to this very interesting process, when
making vegetable spreads, the oils further undergo a process called
hydrogenation, where a hydrogen atom is added to change the chemical structure of
the compound so that it can be solid in room temperature. If you’re not sure
whether your spread had undergone this process ask yourself the question, would
this substance normally be liquid or solid in room temperature? You’ll find
that nothing is solid in room temperature except for pure butter, which is high
in saturated fats that make it solid. You can safely say that any vegetable
spread that you have sitting in your fridge even olive oil spread has been
through this process.
Cold Pressed Seed Oils
There is an argument for cold pressed seed oils versus manufactured oils. The argument is that when cold pressed they do not go through the same highly chemical process that they do when manufactured. This means that they have not been exposed to high heat making them unstable. I am still researching this as it is a valid argument and so far I have not found any proponents to this apart from those promoting these products. A more objective view is needed but for me, thinking about this commonsensically, there is still the issue of the high polyunsaturated fat content which is still a no-no as it causes oxidation, which leads to cell damage in the body. For that reason 'I'm out' as the dragons say but I will still be researching it for you and update you on what I find.
Here’s a list of the types of oils that go through this type of processing:
• Rapeseed Oil (Canola Oil in US)
•
Corn Oil
•
Soybean Oil
•
Vegetable Oil
•
Peanut Oil (Peanuts are not nuts they’re
seeds)
•
Sunflower Oil
•
Safflower Oil
•
Cottonseed Oil
•
Grapeseed Oil
•
Margarine
•
Shortening
•
I Can’t Believe Its Not Butter
•
Any fake butter or vegetable oils products
These oils can also be found in foods such as:
•
Salad Dressings
•
Store Bought Condiments
•
Mayonnaise
•
Chips
•
Artificial Cheeses
•
Store bought nuts and snacks (usually coated
with oil)
•
Cookies
•
Crackers
•
Snack Foods
•
Sauces
Practically anything sold in the middle aisles
of the store!
Better choices:
- Olive oil – raw not heated
- Coconut oil – for cooking, spreading, baking
- Butter – naturally processed but very high in saturates. Be careful not to use it too much! Try using coconut oil instead
- Oily fish
- Nuts
- Avocados
Happy healthy eating!
P.S. The next Lifestyle Seminar will be taking place on Saturday 2nd November 2013. Please see website for details or sign up to our regular newsletter for updates.
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