October 17, 2012

Everything you need to know about fats and oils!

I recently read a great book called Fats that Heal, Fats that Kill. It is simultaneously fascinating, informative, and a little scary - according to this well-researched book, degenerative diseases involving fats prematurely kill over two thirds of people in industrialized nations. TWO THIRDS!!! These include (but are not limited to) cardiovascular disease, cancer and diabetes. As it turns out, most oils in our grocery stores, restaurants and packaged foods are produced, packaged and shipped in ways that are extremely detrimental to our health. In other words, if you're like me and you're willing to make some changes in order to avoid dying a premature death, reading this book (or at least my summary of its important points) has a very good chance of helping you accomplish that goal!!

Rancidity (aka Oxidization)

Despite what I used to think, oils do not have an unlimited shelf life, unless they are so highly processed that they are unable to break down! If an oil smells or tastes "off" or anything but fresh, or no longer smells or tastes like the food it came from, it is probably rancid, and it is in your best interest to throw it out right away. It is a good idea to smell an oil when you first open it so that you will know as soon as it starts to go rancid.

Fats high in saturated fatty acids are somewhat of an exception here. They are solid at room temperature and very stable, so they don't normally go rancid (they are preferred for cooking because of this). Animal fats and tropical oils fall under this category, including butter, ghee, lard, tallow, suet, coconut oil, palm oil, palm kernel oil, and cocoa butter.

There are three things that can cause an oil to go rancid: light, oxygen, and heat. Light is the most destructive, followed by oxygen, and the addition of heat speeds up destruction from both light and oxygen.

Light. Light particles (photons) set off chain reactions in oil molecules, changing their structures so that they become "free radicals". These unnatural substances can no longer be used by our bodies, and our bodies have not developed efficient ways of dealing with them, so they are instead stored as toxins that can lead to a whole host of diseases including cancer and cardiovascular disease. Light also speeds up oxidization (reaction with oxygen leading to rancidity) by 1000 times!

When deciding which oils to buy, look for oils that are stored in dark glass bottles - the darker the better! Oils in clear bottles are most likely refined to the point where they can't break down. Keep the oils in a dark place in your kitchen, such as a dark cupboard or pantry.

Oxygen. Once a container of oil is opened, oxygen enters and the rate of oxidization accelerates. Each oxygen molecule inside the container can set off many free radical chain reactions without being used up, so it's best to buy oils in smaller amounts so that they get used up fairly quickly once they're opened. Keeping an oil in the fridge will extend its shelf life by quite a bit, and keeping it in the freezer will extend it even more.

Delicate oils, like flax and hemp oil, will last as little as 3 months sealed and 3 weeks after opening, if they are kept in the fridge. Keeping them in the freezer will extend this time to a couple of years. Less sensitive oils will last 9-12 months in the fridge once opened, and olive oil will keep up to 2 years in the fridge once opened. Olive oil tends to harden in the fridge after a while, but you can run the bottle under hot tap water for a minute to liquefy the oil when you're ready to use it.

Heat. Heating an oil significantly produces a number of altered molecules that are proven to be toxic. Trans fats are just one of the many toxic substances produced during heating, but they are the least of your worries!

As a general rule, saturated animal fats (solid at room temperature such as butter, ghee, lard, tallow, suet, etc.) should never be heated above 400°F; saturated tropical fats (solid at room temperature such as coconut oil, palm oil, palm kernel oil, cocoa butter, etc.), olive oil, sesame oil, and peanut oil should never be heated above 350°F; and all other oils should never be heated, period!

Frying with oils is especially damaging since it exposes them to light, oxygen and very high temperatures all at once, and the temperature is impossible to control. There is no such thing as "safe frying" when oils are involved, and this should certainly not be done if you are pursuing optimum health or recovering from a degenerative disease. If you insist on frying with oils, however, there are some things you can do to minimize the damage:

  • Follow the general rule in bold above when deciding which fat/oil to use and how high the heat should be.
  • Consider adding a bit of water to the pan - this will help keep the temperature down.
  • Adding sulfur-rich foods such as onions and garlic when frying with fats will reduce the damage done to the fats.
  • Don't barbecue something that is dripping oil; oil + fire = instant carcinogenic smoke which will rise up and coat your food! Also, keep an eye on the temperature when you're barbecueuing since barbecues can quickly reach very high temperatures.

One last note - try to limit your use of peanut and sesame oil, since they have a much higher ratio of omega-6 fatty acids to omega-3's, and this ratio is far from ideal!

Refined Oils

The purpose of refining an oil is to make it completely tasteless, odorless, shelf-stable and heat-stable. During this process, the oil is heated to temperatures as high as 518°F and is stripped of all its nutrients. Fatty acid molecules in the oil are twisted and broken to form unnatural molecular structures with dangerous or unknown effects on our health. As if that's not enough, the chemicals needed to refine oils leave residue behind, and even more chemicals may be added to prevent spoilage, foaming, or clouding. The finished product is nothing but empty calories and a whole lot of scary toxic junk!!

It's difficult sometimes to tell whether an oil is refined because manufacturers aren't required to state it on labels. In most cases, any oil in a clear container is likely refined since protecting it from light is no longer necessary. If the oil tastes nothing like the food it was pressed from (or tastes like nothing for that matter), that is a sure sign it is refined. Avoid anything that says "aroma free". Finally, if an oil is labeled "virgin" or "extra-virgin", you have nothing to worry about - it means it has been made by simple traditional processes, and is therefore pressed without added heat and unrefined. And if you're wondering whether a restaurant used refined oil to cook your food, the answer is probably yes. :(


The purpose of hydrogenation is to turn oils into cheap, spreadable, shelf-stable products. Margarine and shortening are examples of hydrogenated oils. Hydrogenated oils are often used in chocolate too, so that it stays solid in its package.

Hydrogenation involves reacting refined oils with hydrogen gas under high pressure, in the presence of a metal catalyst (usually nickel), for 6-8 hours. Temperatures during hydrogenation are between 248 and 410°F. Aluminum is often used alongside nickel, and in case you haven't heard, aluminum is linked to the development of Alzheimer's disease and osteoporosis. Hydrogenation results in a number of - you guessed it - unnatural altered molecules, with unknown or toxic effects on our bodies.

Just what does cold-pressed mean anyway??

Nothing! Not in North America, at least. There is no commonly accepted definition of "cold-pressed" in North America, nor is the use of this term regulated. It does not mean that the oil is raw - only that no heat was added during pressing. Temperatures during pressing are usually around 185-203°F due to friction regardless of whether the oil is "cold-pressed". What reason would there be to add heat anyway?

Aren't saturated fats bad for me?

It's time to dispel the myths that low-fat diets are healthy for us and saturated fats and cholesterol are bad for us once and for all. They are completely wrong and based on very faulty evidence. Fats that Heal, Fats that Kill supports this outlook and has several chapters' worth of information on the subject.

All of the primitive isolated people that Dr. Weston Price studied ate high-fat diets with liberal amounts of saturated fat. Nourishing Traditions, written by the current president of the Weston Price Foundation, also does an excellent job of explaining the studies that were used to come to the Canada Food Guide's absurd conclusions about fats, and covers in detail a vast number of additional studies showing that diets high in saturated fat and cholesterol are in fact very beneficial to our health and longevity. I won't even attempt to summarize the information in this book on saturated fats and cholesterol, since it does such an excellent job of explaining their benefits by outlining many studies in great detail and I wouldn't want to leave out any important points. I highly recommend this book to anyone interested in the benefits of saturated fats and cholesterol. Actually, it's the most sensible and down-to-earth book on nutrition I've ever owned, not to mention the fact that it's a cookbook with tons of delicious recipes!

Rather than cutting out saturated fat, focus on eating fats from healthy, happy animals who are eating their natural diets and living in the sunlight and fresh air (find out why in this post). Eat fresh, unrefined vegetable oils pressed from organic seeds/nuts/olives/coconuts and avoid hydrogenated fats such as margarine and shortening at all costs.

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