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.
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.
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
4. Cook and bake with butter, coconut oil, olive oil and other heat stable fats. Frankly, these taste a whole lot better than veggie oils anyway, so making this trade should be easy. 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!).
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.
what about sunflower oil?
I don’t personally use it. It’s about 65% polyunsaturated fat, mostly omega-6. Probably okay sparingly, but if you’re trying to reduce your omega-6 load it’s really not a good pick.
Most research on coconut oils and other oils high in saturated fats shows that it isn’t good for your health – it leads to heart disease. Oils such as olive, canola, avocado are much better. I know lots of fitness blogs these days disagree and recommend butter, coconut oil, etc, but they are reading the science wrong. See the sources for these articles:
http://en.wikipedia.org/wiki/Saturated_fat
http://www.mayoclinic.com/health/fat/NU00262
I’m sorry–and I don’t mean to sound rude–but did you read the Wikipedia page you posted? To quote:
“However, high intake of saturated dairy fat does not appear to increase the risk of cardiovascular disease[12] and Pacific island populations who obtain 30-60% of their total caloric intake from fully saturated coconut fat have almost non-existent rates of cardiovascular disease.[13]”
“A study published in 2001 found higher levels of monounsaturated fatty acids (especially oleic acid) in the erythrocyte membranes of postmenopausal women who developed breast cancer.[14] However, another study showed a direct relation between very high consumption of omega-6 polyunsaturated fats and breast cancer in postmenopausal women.[15]”
“An association between serum levels of fatty acids and disease does not in itself establish causality.[29][30]”
“No randomized clinical trials of low-fat diets or low-saturated fat diets of sufficient duration have been carried out. The influence of varying saturated fatty acid intakes against a background of different individual lifestyles and genetic backgrounds should be the focus in future studies.[28]”
And the Mayo Clinic link does not supply any actual sources for the recommendations it advocates.
Not that I consider Wikipedia or the Mayo Clinic website very reputable sources.
Sorry, I linked to the wrong article … what I meant to refer to were the sources at the bottom of this article (sources 19-28):
http://en.wikipedia.org/wiki/Vegetable_fats_and_oils
This article from the Harvard School of Public Medicine also has some sources for reading:
http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-full-story/index.html
I’m not citing Wikipedia as a source, but the sources at the bottom of the article.
As for Pacific islander populations, this is a good example of pseudo-science around claims like yours. The Pacific islanders in the studies ate lots of coconut oil, but their diets are also mostly plant based and they’re also very active (much more so than people in the U.S.) … so you can’t make a good comparison. You can’t point to coconut oil and say this is the reason they had lower levels of cholesterol.
The Harvard article fails completely at demonstrating saturated fats are unhealthy. It provides absolutely NO resources in the “saturated fat is bad” section. In fact the only reasoning they seem to have is that our bodies can produce saturated fat. That’s hardly an infallible argument. The Harvard link also fails to compare polyunsatured fat intake to saturated fat intake in any of its resources. It only compares higher unsaturated fat intake with high carbohydrate intake. In the Wikipedia link, the sources you mention (19-28) prove nothing. In fact, resource 19 demonstrates that saturated fatty acids raise HDL (good) cholesterol far more than LDL (bad) cholesterol! Most of the other resources involved studies on non-human primates, hamsters and mice–not humans. And the seven countries study? That study is heavily flawed. It did not examine a random selection of countries (only those Keys hand-picked) nor did it look at total mortality, longevity or any other factors other than fat intake.
Here’s a GREAT article that talks a bit about why we even have this discussion in America. http://www.coconutoil.com/oiling_america.htm
Here’s an article to toss into the debate. It is from a major medical journal, and amazingly (gasp) has NOT had any media pick up on it! I wonder why? Here’s the link… happy reading.
http://www.ajcn.org/cgi/content/abstract/ajcn.2009.27725v1
Great find! Thanks for sharing. Too bad the media is so skewed it never picks up on studies like this.
I agree with the need to decrease O-6s, but some of your science is not completely balanced.
What about the damage to endothelial cells and the decrease in nitric oxide release in the arteries with any type of fat including coconut oil, mufas, pufas and other saturated fats? Also, nowhere is it stated that PUFA are the only oils which have shown consistently to increase HDL.
I agree with Dr. Esselystyn that no concentrated oils good for vascular health.
There is definitely more than one side to this story. Heart disease, cancer and other conditions are multifaceted issues, and usually science and research is only looking at one part of a very large picture. I believe this is why different studies appear contradictory. There are numerous studies that show health benefits of coconut oil and other saturated fats, but in the end they still only show on side of the picture. Usually a person’s individual metabolic health is what determines how their body reacts to different foods and nutrients (one man’s medicine is another man’s poison so to speak).