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The Hidden Dangers of Vegetable Oils

There’s a popular kitchen staple that could be raising your risk for heart disease, cancer and obesity – we’re talking about vegetable oils here. We’ll be diving into the debate around the health and safety of a number of these oil varieties  here’s what you need to know.

It can feel near impossible to find processed and packaged foods without vegetable oils lurking within  from chips to spreads, bread and margarine. Your Friday-night takeaway from your favourite restaurant is likely also harbouring these unhealthy oils. But it wasn't always like this. Commercial, industrial vegetable oils are actually a recent addition to our pantries – it wasn’t until the early 20th century that we developed these cheap, accessible alternatives to butter, lard and olive oil. But they came at a greater cost to our health. These vegetable oils are a distant creation to the ingredients they’re derived from – soy bean oil, for instance, is made by extracting the oil from the beans, then refining the product further into a substance that has been found to create metabolic and neurological changes in some alarming studies. Then we’ve got canola oil, which wasn’t even in existence until late last century – this crop was created in Canada in 1974 for the sole purpose of making oil more efficiently than traditional rapeseed crops.

The issue with a number of vegetable oils is their heat sensitivity, potential to release dangerous chemicals and trans-fat content - and with people consuming an average of over 30 kilos of veggie oils each year, we’re starting to see the consequences. Let’s dive into the issues these oils pose to your health – plus a few healthier alternatives to vegetable oils.

Omega 6 content

A number of vegetable oils have an imbalanced omega 3 ratio as they tend to be particularly high in omega 6, and while this essential fatty acid isn’t necessarily bad for you, in fact, it’s essential, hence the name, as our bodies can’t produce these fats on their own, but problems arise when we take in a suboptimal ratio of omegas. It’s only been in the last century that we’ve seen drastic changes to our omega 3 and 6 ratio intake – and the industrialisation of vegetable oil plays a major role in this trend. The ratio has gone from around 1:1 to a whopping 20:1 of omega 6 to omega 3, but studies have shown that this kind of imbalance can result in chronic inflammation and a range of diseases that come with this inflammation, from heart disease and arthritis to cancer. More concerningly, studies have directly linked excessive omega 6 intake to chronic inflammation, indicating a potential health crisis is on our hands when considering the mass use of vegetable oils. Though, it’s worth noting other studies suggest the results are inconclusive, with some research finding that one omega 6 acid known as linoleic acid did not drive inflammation – so, while the implications are still up for debate, what we do know is that getting a good omega 6 to 3 ratio is still important for optimal health. Take a look at the varieties you’ll want to avoid when it comes to omega 6 content:

  • Soybean oil
  • Sunflower oil
  • Sesame oil
  • Peanut oil
  • Corn oil
  • Rice bran oil

Trans fats

Many vegetable oils are high in trans fats – this is because they’ve been hydrogenated, a process that hardens the oils, as you’d find in margarine, and this is one of the reasons margarine can be a trans-fat haven, despite the war on fat pushing people away from butter, it’s clear that the suggested alternatives were certainly not healthful choices.

The issue here is that trans fats have been linked with heart disease, cancer, diabetes and obesity in a number of studies, so it’s best to avoid hydrogenated vegetable oils – and you’ll find most of the commercial, highly-processed varieties are, in fact, hydrogenised.

Heat sensitivity and oxidisation

Many vegetable oils are sensitive to heat, often breaking down and oxidising when hitting those high cooking temperatures. This is because these oils are high in polyunsaturated fats which are notoriously unstable when it comes to heat, leading to a quick oxidisation process – when we consume the oxidised oil we put ourselves at risk for inflammation. But there’s another major issue with heating some of these oils – often they’ll release dangerous chemicals known as aldehydes. These have been associated with the development of dementia, along with heart disease and cancer. In fact, research has shown that veggie oils used to fry fish and chips contained hundreds of times as much of these toxins than the World Health Organisation’s daily limit. Yikes. To put that into perspective, heating olive oil or butter – both of which can also be sensitive to high heats – produced a drastically lower amount of these toxins, with coconut oil boasting the lowest aldehyde content when heated. Research has also shown that the consumption of oxidised oils can cause our own cells to be more vulnerable to oxidisation – thereby putting us as greater risk for the development of disease. This is because these fats aren’t just used for energy, they’re also stored in our cell membranes – something to think about when choosing and oil! But don’t worry, we’ll show you a few safe alternatives.

Alternatives to vegetable oils

It’s worth noting that not all oils are bad – some plant-based oils are safe and even pose exceptional health benefits. Let’s get into a few of the best oil and fat options to add to your plate.

  • Extra virgin olive oil: This stuff is loaded with antioxidants and healthy fats for heart, brain and gut function. Just be sure not to deep-fry with this stuff – it can be oxidised and you’ll lose some of those health-boosting nutrients. Light heating is fine, but it’s delicious to simply add a cold tablespoon to your salads or soups.
  • Coconut oil: This stuff is great for cooking as it has a higher smoke point that other oils, meaning you’re at a lower risk of consuming toxins. It’s also a good source of healthy fats and minerals.
  • Ghee: This is another ideal cooking fat as it has a high smoke point. It’s also rich in omega 3 – with an impressive ratio of 1.5:1 – and is loaded with vitamin A and vitamin D, both of which are fat soluble, so you’ll be killing two birds with one stone.
  • Avocado oil: This oil has a high smoke point, making it another great option for cooking. It’s also rich in oleic acid, which has been found to reduce our risk for inflammation, along with an antioxidant known as lutein – this stuff is known for its protective properties for our eye health.

Ideally, opt for minimally-processed oils and steer clear of those hydrogenated vegetable oils!

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