For years we've been told to avoid butter and instead use vegetable oils as our primary fat source. Mainstream science claims this will save our hearts. But industrial oils like soybean, corn and canola oil are hiding a dirty little secret: consuming them could very well increase your risk of cancer.
What Are Polyunsaturated Fats?
Saturated fats have no double bonds (like those in coconut oil) and monounsaturated fats (like those in olive oil) have one double bond. However, polyunsaturated fats (also known as PUFAs for short) are linked by multiple double bonds. This is what makes polyunsaturated oils highly unstable and fare more vulnerable to oxidation than other fats. Bruce Fife offers an excellent explanation of the different kinds of fats and how they affect our health is his book The Coconut Oil Miracle.
The Cancer Connection
Many experts now acknowledge that refined polyunsaturated oils are damaged fats and should be avoided. This leads to the assumption that cold-pressed organic oils are inherently acceptable because they are less refined. However, even gently processed polyunsaturated oils are unstable, and oxidation can still occur once these fats are in the body. And oxidation is linked to cancer and other degenerative diseases.
In addition to the dangers of oxidation, there are also bonafide concerns about the omega-6 content of polyunsaturated oils. A recent San Francisco study demonstrated that under laboratory conditions, omega-6 fatty acids could accelerate the growth of prostate tumor cells.
Other studies show that improving the omega-3 to omega-6 ratio can lower the risk of certain cancers. Experts vary in their specific ratio recommendations, but most suggest a ratio of between 1:1 and 1:4 at most. The average modern diet has an omega-3 to omega-6 ratio of 1:20 (or more!).
The blame for this imbalance can be squarely placed on the rapid increase of vegetable oils in our diets during the past century:
While some vegetable oils do contain small amounts of omega-3 fatty acids, for the most part they consist of omega-6. Eating more vegetable oils does nothing to correct the imbalance of omega 3 to omega 6 fatty acids in our diet.
To combat this effect, the typical recommendation is to increase omega-3 consumption. That's kind like bailing water out of a sinking ship with a baseball cap. This problem is far more effectively resolved by reducing omega-6 intake. Eliminating or drastically decreasing polyunsaturated oil consumption is the best way to do this.
How to Decrease Your Polyunsaturated Fat Intake
Here's how you can cut excess PUFAs from your diet:
1. Avoid commercial fried foods. With very few exceptions, these are cooked in polyunsaturated oils and contain highly damaged fats.
2. Avoid commercial salad dressings, mayonnaise and other fatty condiments. Unless otherwise noted, these are generally made with refined vegetable oils.
3. Avoid commercial baked goods. Riddled with bleached flour, refined sugar and chemical additives, these items should be avoided in general for obvious reasons. But their high PUFA content gives you yet another good reason for leaving these items on the shelf where they belong.
Find quality sources of healthy oils here.
5. Go easy on the nuts. While these may be hailed as a health food by many experts, in excess nuts can easily skew your omega-3 to omega-6 ratio and push your polyunsaturated fat intake over the limit. A few servings a week is more than enough, though I personally choose to eat them even more sparingly than that. Hazelnuts and macadamia nuts are the most forgiving since these contain the lowest PUFA content (and they also taste pretty darn good!).
A Historical Perspective on Vegetable Oils
Traditional cultures simply did not liberally use polyunsaturated oils in their diets. Keep in mind that these cultures often exhibited excellent health and did not suffer from modern diseases such as diabetes, cancer and heart disease. Weston A. Price noted in his book Nutrition and Physical Degeneration that industrial vegetable oils were one of the modern foods that brought health problems to traditional people when they started using these oils in their diets. We should take a hint from our ancestors and ditch the industrial fats.
Need help finding high quality, healthy oils? Check out my Resources page.
This post is part of Real Food Wednesday hosted by Kelly the Kitchen Kop.