The thought that fats are bad needs to GTFO of everyone's heads. Fats are not only essential to our survival, but key to our performance and long-term health. In fact, our brains are made of nearly 60% fat , and guess what our cell membranes (that wrap every single cell in our body) are made of? You guessed it: fat. So when people talk about low fat diets, it makes us want to cry — they systematically deprive you of what your body needs to function at its best.
So let's get the lowdown on fats, discover what omega 3s and 6s are, and find out why Dr Cate Shanahan (a doctor with over two decades of clinical experience in genetic and biochemical research) calls vegetable oils 'liquid death'.
One of our heroes Dave Asprey  explains this incredibly well. There are three main types, and each behave differently within our bodies, largely due to two very important factors: the fat's tail and its stability.
Check the fat's tail
Fat molecules look kind of like mice: they have wide bodies with thin tails coming off them. As a general rule, the shorter the tail, the more rare and anti-inflammatory the fat itself.
Know the fat's stability
The stability of a fat largely depends on how many binding sites it has open. Fats with fewer open binding sites are more stable – they’re less likely to let a free radical oxidize them by stealing an electron. Oxidized fats speed up aging and create inflammation, which is a bad, bad thing.
Here are the three types of fat, from most stable to least:
In saturated fats, all the binding sites are filled ("saturated”). You'll see on the diagram below, it’s like a big dinner table, and each “H” is like a person in a chair. Every seat at the table is taken, so a free radical can’t get in anywhere to grab an electron and oxidize the fat.
Monounsaturated fats are relatively stable, but they’re not quite as stable as saturated fats. “Mono”, meaning one, indicates that there is one place for a free radical to enter.
Polyunsaturated fats are the least stable fats. Poly is Greek for “many,” and as the name suggests, they have multiple binding sites exposed, making them particularly open to oxidation, as it’s easy for the free radical to get in and mess with the fat.
It’s important to note that just because a fat is unstable doesn’t mean it’s bad for you (in fact, two types of the most important kinds of fats are unstable: omega 6 and omega 3). You should just handle less stable fats more carefully to make sure they don’t oxidize or spoil. That means avoiding ones that are heavily processed or exposed to high heat. Always buy oils in dark, thick glass bottles and keep them out of direct sunlight.
Omega 6 and omega 3 fats are key to survival. Because our bodies can’t produce them on their own, we have to get them from food. Omega 3s and omega 6s exist in a ratio to one another. There’s a cap on the total amount of the two that your body can use, so they compete for space. Omega 6s are inflammatory, while omega 3s are not. We need a TINY amount of omega 6s for survival, any more and they're incredibly bad for you, which is why we should optimise omega 3s and minimize omega 6s.
It's largely agreed that we should look for a ratio of 4:1 of omega 6s to 3s (and many anti-ageing experts would go further and recommend a ratio of 1:1). But on average we're consuming between 10:1 and 25:1, that's up to 25 times more omega 6 than we should! This. Is. Not. Okay. In fact, it's catastrophic.
Largely due to the oil in our foods. Vegetable oils (think sunflower, safflower, rapeseed oil...) are cheap to produce, and you'll find them inside processed foods like biscuits, ready meals, margarine, granola, even 'healthy' snack bars. Seriously, take a lot at some labels and you'll be surprised. When companies use these oils in packaged foods, they stabilise them to increase the shelf life through a process called hydrogenation. Hydrogenation takes already harmful fats and converts them into synthetic trans fat, making them toxic and even worse for you. You should avoid these oils, and any processed foods containing them.
As we know, omega 6 oils are unstable because they’re made of polyunsaturated fats (lots of seats open at the table). Cooking at high heats, microwaving, or frying oxidizes the fats. Oxidized omega 6s damages your DNA, inflames your heart and tissues, and raises your risk for several types of cancer (including breast cancer) and it interferes with brain metabolism [3, 4, 5, 6, 7].
Essentially it puts us in a state of chronic inflammation. And as Dr Terry Whals tells us , if we look at many of our western diseases (brain and heart diseases, certain cancers, auto-immune diseases, and neurodegenerative diseases like alzeimers and Huntington's) at a molecular and cellular level, they all look almost exactly the same. They all have inflammation, oxidisation and toxins present...not good. But, by becoming aware of our omega 3 and 6 balance, we can optimise our diet for longterm health.
There are three common types of omega 3 fatty acids:
Without a doubt, the most amazing and number one source of omega 3s is oily fish. Grass-fed beef and various nuts and seeds are also great, and the charts below will give you a good idea of some of the foods to optimise. We recommend supplementing your diet with a high quality omega 3 oil (be sure to check the levels of DHA and EPA).
Here are our top three cooking oils:
As a saturated fat, coconut oil is very stable and great for cooking at high heat. Its saturated fatty acids are mainly lauric acid and caprylic acid, which have virtually no bearing on your Omega 3-6 balance (and also to thank for its health benefits). You can get unflavoured coconut oil too, which is brilliant if you don't like the taste, or don't want it to affect the flavour of your dish.
Butter's been unfairly demonised because of it's saturated fat content, which we now know is rubbish (there's no link between bad cholesterol and saturated fat). In fact, real butter (NOT margarine) is high in Vitamin A, D and K2, as well as other healthy fatty acids CLA and butyrate. Make sure it's organic and grass-fed as it's more nutritious – the yellower the colour the better.
A staple of the Mediterranean diet, it has 75% of its fatty acids as Oleic acid (aka Omega 9, which has no effect on the omega 3-6 balance). Oleic acid is also great at reducing inflammation, and is well known for it's health benefits. Opt for an extra virgin olive oil as it's cold-pressed and unrefined (no additives or chemicals involves). Also choose dark packaging to help keep it stable – and unlike butter, the colour of the oil is no reflection on quality.
There's no denying that it would be more expensive for companies to use healthy fats, rather than cheap alternatives that are causing us long-term damage. But the the real question isn't 'why is healthy food so expensive?'. It's 'why is processed food so cheap?'
References and further reading