Fat is an important part of our natural diet that has gotten a bad rap in recent years. In this Deep Dive, we will look at the different types of fat and guide you to a healthy fat consumption. For this, oils and fats are both considered fats. The only real difference between the two is whether their melting point is higher or lower than (the rather arbitrary) room temperature.
The biggest villain in our “fat is bad” fantasy novel. Most of the saturated fats we eat come from animals, although some vegetable and nut oils (like coconut oil) are also high in saturated fats. There is no real evidence that saturated fats cause heart disease. Saturated fats are very stable, meaning they are unlikely to oxidize. This makes them great for cooking and less likely to cause inflammation in your body. Recent evidence suggests that if you replace unstable seed oils with stable saturated fats, you even decrease your risk of heart disease.
It is good to note that any natural fat is always a mixture of saturated and unsaturated fats, even animal or coconut fat. When we talk about a saturated fat, we generally mean a fat that is predominantly saturated.
Chemically, unsaturated fats are fatty acid chains where one or more links do not have the maximum possible number of hydrogen atoms around them. If one link is incomplete, it is called a monounsaturated fat. If it is multiple links, it is called a polyunsaturated fat. Polyunsaturated fats are especially susceptible to oxidative damage. This leads to a process called rancidification, which occurs naturally in all unsaturated fats but is slowed down by the presence of antioxidants. Rancid fats can be toxic, inflammatory and carcinogenic.
Most unsaturated fats in their natural form are protected from oxidation by the skin of the animal or plant as wel as naturally present antioxidants. However, in highly processed oils like rapeseed oil and sunflower oil most of these antioxidants are removed during processing. The processing also puts stress on the fatty acids, causing oxidative damage before the oil even gets to your home. Then, when you heat the oil during cooking, it oxidizes even further. Monounsaturated fats like olive oil and most animal fats oxidize much slower than seed oils. Saturated fats like coconut oil and butter oxidize extremely slowly. The more a fat is oxidized, the higher the risk of it causing inflammation in your body.
Of course, the industry wasn’t taking all of this lying down. They needed a long shelf life, not fats that went rancid as soon as you looked at them. To prevent rancidity, the seed oil industry started to partially hydrogenate their fats, extending their shelf life and making them easier to process in factories. These chemically altered fats were sold as margarine and shortening (used in bakeries). However, hydrogenating fats introduces a new problem. The chemical process that adds hydrogen atoms changes the shape of some fatty acids from their natural form into a different form (called a trans fat). Although trans fats do occur naturally in dairy and beef, those specific trans fats have been shown to be harmless or even beneficial. The artificial trans fats that originate from industrial hydrogenation have been identified as a cause of inflammation and heart disease. Unfortunately, manufacturers are not yet required to list trans fat content on foods, but be wary of highly processed foods in general, especially baked goods and spreads.
Based on the above, you could conclude that you should replace all your fat with nicely saturated coconut oil. But unsaturated fats are important for your body for several reasons. First, fats from different sources contain different vitamins and other nutrients. And more importantly, there are two essential fatty acids your body can’t produce on its own: these are called omega-3 and omega-6 fat, and they are both polyunsaturated fats. It is important to get enough of both, but omega-3 is generally the more difficult to get enough of. The best natural sources of omega-3 are fatty fish such as mackerel, salmon, herring and tuna, as well as egg yolks.
At the risk of sounding like a broken record, our advice is to vary your fat intake. Don’t go on a quest to find the ultimate superfat, but alternate between fatty fish, animal fats, olive oil, coconut oil and butter. Just leave out the industrial seed oils and margarine, you’re better off without those.