Monday, May 01, 2006

And the Healthiest Oil is…


With so many choices for cooking oil at the grocery store, and so many reports in health news, I've often been perplexed when trying to decide which oil I should buy.

Based on a couple hours of research, I found that a mix of oils (especially olive oil, a monounsaturated fat and canola oil, a polyunsaturated fat) -- used in moderation -- is best. And if you think that's a complicated statement, you're right. But it's appropriate for the subject. If I learned anything in the time I spent researching this issue, it's that nutritional matters are deeply complex and greatly confusing.


Coconut oil?
I started my quest by googling the phrase "healthiest oil." Try it, and you'll find that the first few pages are packed with content singing the praises of coconut oil. Surprised? I was. First of all, coconut oil is a saturated fat. Second of all, where was olive oil? I was pretty sure that olive oil would be the healthiest, but it was nowhere to be seen.


After digging into some of the coconut oil articles, I found most of them were published at new age or alternative medicine websites. You won't find the American Heart Association, the Food and Drug Administration or many mainstream doctors encouraging coconut oil (though I learned that coconut oil is used to feed newborns and in I.V. drips).

Another thing I noticed is that some of the most persuasive writing on coconut oil, at a website called Mercola.com (as in Dr. Joseph Mercola), led straight to a page where you could buy coconut oil. And though I was able to corroborate a lot of the writing at Mercola.com with other websites, I was skeptical -- any time an article is connected to a shopping cart, a caution light starts flashing in my head. For a sanity check, I went to WebMD.

At WebMD, I did find an article sorting out
the facts on coconut oil. And there are some benefits there. But as I widened my search to more mainstream news sources, most of the content supported olive oil and canola oil as healthiest.

The health benefits of fat
Before getting into which oil is best, let's look at why you need fat in the first place.

Here's what Cindy Moore, MS, RD, director of nutrition therapy for the Cleveland Clinic Foundation, and spokeswoman for the American Dietetic Association
told WebMD:


"Fats and oils provide a concentrated source of energy for the body. Fats are used to store energy in the body, insulate body tissues, and transport fat-soluble vitamins -- A, E, D, and K -- through the blood. They also enhance the taste, aroma, and texture of food, and contribute to a feeling of satiety, or fullness." (1)

Over at Mercola.com, Dr. Mary Enig and Sally Fallon point out that fats also "provide the building blocks for cell membranes and a variety of hormones and hormonelike substances." (2)


Types of fat
There are three basic types of fat: saturated, monounsaturated and polyunsaturated. For a technical explanation of the differences between these,
visit Dr. Mary Enic and Sally Fallon here-- be warned, you need to brush up on your chemistry if you expect this to make sense.

If you're not ready for a chemistry exercise, all you need to know is that saturated fat can raise your bad (LDL) cholesterol level (which puts you at greater risk for heart disease) while monounsaturated and polyunsaturated can lower bad cholesterol. For a laymen's breakdown on different fats,
visit the American Diabetes Association here.

Saturated fat may also cause cancer. For example, a
2003 study linked saturated fats to breast cancer.

That narrows the search for healthiest oil down to monounsaturated and polyunsaturated, but in those categories there a lot of choices (in fact, many oils contain both polyunsaturated, monounsaturated and saturated fat). For example, there's canola, corn, flaxseed, olive, peanut, safflower, sesame seed, soybean, sunflower, vegetable, and others. So, which to choose? Whether it's because these oils are widely available, or that most research has focused on them because they're so popular, the two that came up most in my research were canola oil and olive oil.

Olive Oil
Every day, it seems that another study reveals more benefits of olive oil. It lowers blood pressure, reduces the risk of heart disease and helps prevent cancer. But it's not the fat, its plant compounds that deserve the credit.

According to
a recent article at MSNBC.MSN.com, "Research now shows that many of olive oil’s health benefits may actually come from the more than 30 plant compounds it contains. These compounds’ antioxidant and anti-inflammatory effects promote heart health and protect against cancer." (5)

In a study of 22,000 Greeks, cited by WebMD, "those who followed a Mediterranean diet, which is rich in olive oil, lowered their risk of death from heart disease by 33 percent and their cancer rate by 24 percent compared with volunteers who ate other foods." (
1)

The power of olive oil seems to come from what it does and does not cause the body to make. According to the MSNBC piece, olive oil increases enzymes that block cancer and decreases the production of bile, which promotes colon cancer. (
5)

While reports on olive oil are usually glowing, there was a report in 2000 suggesting olive oil had some negative affects. The small study,
which you can find at WebMD, showed that olive oil constricts arteries enough to restrict blood flow by 34 percent after meals.

That's the same amount as a Big Mac and fries.

Some doctors believe that constriction of this amount can cause damage to arterioles. By contrast, canola oil only restricted arteries by 11 percent.

But don't drop your olive oil in the trash just yet. Instead, try picking up a carrot, and maybe some broccoli. In the study, "when olive oil is combined with foods rich in antioxidants, such as vegetables, the vessel-constricting effect disappears."

Canola Oil
While the health benefits of olive oil are numerous, it is missing compounds called essential fatty acids. What makes them essential is the fact that your body needs them, but can not make them. According to WebMD, these essential compounds are needed for cell structure and making hormones. (
1) And while monounsaturated fats like olive oil do not contain them, polyunsaturated fats like canola oil are a great source of essential fatty acids.

"[Canola oil] has what is considered to be an almost ideal balance of omega-6 to omega-3 fatty acids, two essential fatty acids that are vital in for health," reports WebMD. (
1)

One affect of omega 3s is reduced inflammation, according to MSNBC's Karen Collins, R.D. Reduced inflammation lowers risks for heart disease and cancer. (
5)

Another benefit of canola over olive oil is the fact that it's lower in saturated fat (both canola and olive oil contain some saturated fat).

For cooking, canola oil also has the edge over olive. According to Collins, "From a cook’s perspective, olive oil may not be the best choice for cooking at a high temperature. The sediment naturally found in extra virgin olive oil can make it more likely to burn or smoke. Canola and peanut oils have a higher smoke point." (
5)

Not everyone agrees with Collins on her cooking advice. For example, medical advice site Ask Dr. Sears suggests olive oil is best for cooking. While the site acknowledges that, "Cooking at high temperatures can damage oils," it points out that, "oils that are higher in saturated fats or monounsaturates are the most stable when heated. These include peanut oil and olive oil." (
5)

If you can't use olive oil to prepare your next stir fry, Ask Dr. Sears suggests a cooking technique called wet-sauté.

From Ask Dr. Sears: "Try the 'wet-sauté,' a technique that is practiced by gourmet chefs. Pour around one-fourth of a cup of water in the stirfry pan and heat just below boiling. Then add the food and cook it a bit before adding the oil. Wet-sauté shortens the time oil is in contact with a hot pan. Stir frequently to further reduce the time the oil is in contact with the hot metal." (
5)

I just tried this technique and found that I didn't even need to use oil. Besides, after doing this report, I'm questioning all the oil in my cupboards.

By the way, you may be questioning canola oil. What is it? The word "canola" is a mix of "Canada" and "oil." WebMD explains, "Canola is a form of rapeseed that was specially bred in Canada by traditional plant breeding techniques to change the chemical composition of rapeseed." (
1)

Since both canola and olive oil have unique properties, a mix of both is probably best.

K.C. Hayes, professor of biology at Brandeis University tells WebMD, "While we should do what we can to stay away from saturated fats and trans fatty acids, taking in a combination of monounsaturated and polyunsaturated fats keeps us nutritionally balanced.

Choosing the right Olive or Canola oil
Now that you know you should be using both olive and canola oil to promote good health, an important question arises: which olive or canola oil should I buy? If you've paid attention to the choices in supermarket lately, you know there are many varieties of both canola and olive oil

For olive oil, Karen Collin's MSNBC column explains, "All types of olive oil provide the monounsaturated fat linked with health benefits, but to get the highest levels of the protective plant compounds, choose 'extra virgin' or 'virgin' oil, the least processed forms." (
5)

When it comes to oil, it pays to buy organic as well. According to Ask Dr. Sears,

"It's definitely worthwhile to pay extra for organic oils. Many oils come from plants that are sprayed with pesticides, which are usually fat-soluble, and thus concentrate in the oil portion of the plant. One of the safest oils is extra virgin oil, which is not refined or deodorized, and may even be organically grown." (
6)

Another thing to look out for is how oil is refined. According to Ask Dr. Sears, heat processing and refinement with "potentially toxic substances" can "leave chemical residues behind." "If the label does not boast that the oil is "unrefined," you can assume that it has been through some kind of chemical process that makes it worse for your health," the site explains.

The problem with excessive heat used in refining, according to Ask Dr. Sears, is that it can "damage oils and alter the fatty acids, creating harmful substances, so the best oils are produced with minimal heat." Look for "omegaflow process" on a label. Basically, this means that high temps were not used in processing.

Once you've purchased the right oil, there's still more to know. First of all, oil has a short shelf life. According to WebMD, "levels of antioxidants in olive oil fell sharply after 12 months in storage -- even under the best of storage conditions." (
3)

Oil is also sensitive to light. WebMD, Karen Collins' MSNBC column and Ask Dr. Sears all warn consumers not to keep oil in cool, dark places. If possible, do not buy oil in glass or clear plastic bottles.

According to Ask Dr. Sears, "Clear glass or plastic bottles allow light to penetrate the oil and oxidize the fatty acids in a chemical process similar to metal rusting. If the oil comes in a clear bottle, wrap it with a dark covering. Keep the lid on tightly between uses, as contact with air will affect the quality of the oil." (
6)

Now, my only question is, when I find a bottle of organic, extra virgin, omegaflow processed, unrefined olive oil in a dark bottle, how much is it going to cost? With my current income, how sustainable will a diet based on such specific oils be? Also, I hope I can leave my obsession with oil at the door; I would hate to be the waiter that has to answer half of the questions I raised in this article.


Resources
(1) Time For An Oil Change? [WebMD]

(2) The Truth About Saturated Fat [Mercola.com]

(3) All About Olive Oil [WebMD]

(4) Say No to Olive Oil? [WebMD]

(5) Olive oil brings more than flavor to your diet [MSNBC]

(6) All About Oils [Ask Dr. Sears]

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.