Tuesday, May 31, 2011

Your Vegetable Oil is Killing You

So you’re going Paleo. You’ve stopped dumping sugar into your morning coffee, and you’re tossing your old stash of Halloween candies. You’ve purged your pantry of all grains and legumes, and you’ve made peace with the fact that your family’s pizza night is now a thing of the past. Good on ya.

But are you still cooking with vegetable oil?

"Vegetable oil" certainly sounds healthy, doesn't it? After all, the stuff comes from vegetables, and we all know that vegetables are good for you! These oils are probably made by just taking a bunch of garden-fresh veggies like kale and cabbage and squeezing ‘em really, really hard until they release a stream of golden ooze, right?

Not quite. Sure, a small number of oils are produced via extraction and minimal processing from plant sources, like avocado oil, coconut oil or olive oil. But that’s not what we’re talking about here -- we’re talking about the vast majority of vegetable oils found on supermarket shelves (and in just about all processed food products), which are made from seeds, grains and legumes. Stuff like:
  • Canola (rapeseed) oil
  • Corn oil
  • Soybean oil
  • Rice bran oil
  • Sunflower oil
  • Safflower oil
  • Peanut oil
  • Cottonseed oil
These oils are easy to work with in the kitchen -- most of 'em don't add funky flavors or odors to your food, and they generally have high smoke points (meaning they can be heated to higher temperatures before smoking and discoloring). Plus, they’re cheap!

But you should avoid 'em like the plague. Why?

Vegetable oils are Omega-6-heavy polyunsaturated fats (a.k.a. PUFAs – polyunsaturated fatty acids) that put you at risk for heart problems, obesity, systemic inflammation, and other super-fun health disasters.

PUFAs oxidize like crazy. Unlike stable, oxidation-resistant saturated fats like animal fat and coconut oil, PUFAs are highly unstable and reactive to oxidation. Oxidation occurs when an unstable free radical of oxygen takes an electron from another molecule – thus “oxidizing” that molecule and rendering it unstable.

PUFA oils are so unstable that even when stored at room temp, they become rancid to some degree. And when you heat the oil, the oxidation and free radical formation accelerate. You can’t smell or taste those delicious free radicals, but once you ingest ‘em, they’ll wreak havoc on your body. As Mark Sisson puts it:
The free radicals make their way through the body pillaging at every turn. Their damage takes a toll on everything from cell membranes, to DNA/RNA strands, to blood vessels (which can then lead to plaque accumulation). The harm adds up over time in the organs and systems of the body and can cause significant impact, including premature aging and skin disease, liver damage, immune dysfunction, and even cancer.
Plus: Vegetable oils are HEAVILY processed and repeatedly soaked with hexane.

Some fun hexane facts:

So throw away that sticky bottle of vegetable oil that’s been sitting in your pantry for months. It’s chock-full of very bad things.

Instead, for high temperature cooking, use saturated fats like coconut oil and ghee, both of which remain extremely stable under heat. (And don't be afraid of the word "saturated." Most people assume it means that the fat is SUPER-DUPER artery clogging, when in fact, it just means that it has no double-bonds between the individual carbon atoms of the fatty acid chain. In other words, the chain of carbon atoms is fully "saturated" with hydrogen atoms, making it more chemically stable. The fact that it's "saturated" doesn't make it bad.)

True, coconut oil and ghee aren't as dirt cheap as canola oil. But if I were you, I’d pay a little extra not to ingest body-wrecking stuff that’s treated with chemicals used to make roofing glue and to poison the good people who made your iPhone.