Here are some simple answers to tricky questions about fats.

Our relationship with fat continues to baffle us. We love it, then we hate it. It comforts us, then frightens us. Unlike sugar, which we've come to universally vilify, fat makes us sway with indecision.

Guard Against Heart Disease

"Research has proven that the omega-3 EFAs in fish oil lower blood pressure, lower triglycerides (high levels of which are a risk for heart attacks). And slow atherosclerosis (the growth of harmful plaque)."

Decker Weiss, ND, is the first naturopathic physician to complete a residency program in the Columbia Hospital System, the Arizona Heart Hospital, and the prestigious Arizona Heart Institute. He is also the first naturopathic physician to be on staff at a conventional hospital, the Arizona Heart Hospital, where he has served for seven years.

Meanwhile, conflicting claims abound. Saturated fat clogs our arteries, but coconut oil lowers cholesterol. Canola oil is high in healthful monounsaturated fats, but it's toxic. Flax is loaded with omega-3 fats, but they're the wrong kind. Which are real-life facts, and which are big, fat lies? Some answers to the most frequently asked fat questions follow.

I know saturated fats are supposed to be bad for me, but what's the difference between monounsaturated and polyunsaturated fats, and which are more healthful?

In chemical terms, monounsaturated fats contain one double bond in their structures, while polyunsaturated fats contain two or more double bonds, making them more "bendy" and prone to damage. Which are more healthful? That depends. Both have similar effects on cholesterol levels, but studies suggest that monounsaturated fats lower the risk for breast cancer, while polyunsaturated fats appear to increase risk.

Additionally, some foods that are high in monounsaturated fats have additional benefits. Olive oil is rich in compounds that have antioxidant properties and anti-inflammatory effects, and many studies have found that almonds are extremely effective at lowering LDL cholesterol while raising HDL levels. Peanuts raise HDL levels, especially in people with diabetes; they're also rich in resveratrol, which fights inflammation and has heart-protective effects. Other foods rich in monounsaturated fats include avocados, macadamia nuts, and canola oil.

I've heard that canola oil is harmful; is that just an urban myth? 

Yes and no. The idea that canola oil contains high levels of toxins comes from the fact that it used to be produced from the rapeseed plant, a weed that's used to make mechanical oils; rapeseed is naturally high in erucic acid, a compound used as a lubricant in industrial processes that's toxic to humans in high quantities (hence the toxicity rumor). The rapeseed was then crossbred to develop a canola plant that does not contain erucic acid. Canola is named for Canadian oil, the main supplier of the product, since "rape plant" clearly has some marketing issues. The canola plant, not the rapeseed, is now used to make canola oil. All the other stuff about mustard gas and toxic fumes is urban myth.

However, many damning studies have cast suspicion on canola oil. It has been implicated in the formation of lesions in the arteries, and more recent studies noted that canola oil markedly shortened the survival rate of animals. Canola oil originally had a high polyunsaturated fat content. However, in the last few years canola oils have been developed that have a higher monounsaturated content. It's probably safer to stick with olive oil, which has a vast body of clinical research and historical use, for your monounsaturated fats.

Boost Your Total Health

"Omega-3 fatty acids are dangerously low in the American diet, leading to multiple health problems. Fish and flax oils are our most abundant sources of omega-3s and help to regulate inflammation, immunity, heart function, blood pressure, blood clotting, brain function, mood, and cancer risk. Even the FDA acknowledges the benefits of omega-3s. Barlean's Omega Swirl is an innovative new solution for the whole family due to its astoundingly delicious taste and smoothie texture."

Herb Joiner Bey, ND, is a seasoned clinician, educator, seminar leader, public speaker, medical editor, medical consultant, and author in therapeutic nutrition, Western botanical medicine, and classical homeopathy. He is the author of The Healing Power of Flax and several other books.

EFA, ALA, EPA, DHA, LA, GLA, AA-I'm confused by this alphabet soup of oils. What do all these letters mean? 

They all refer to types of polyunsaturated fats. Here's how it works: omega-3 and omega-6 fats are both referred to as essential fatty acids (EFAs); the body can't make them, so we have to get them from our diets. The three main omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is found mainly in flax and nuts, DHA and EPA are found mainly in fish. Omega-6 fatty acids include linoleic acid (LA), gamma-linolenic acid (GLA), arachidonic acid (AA), and others.

Can I eat flax instead of fish to get omega-3 fats? 

Yes and no. Flax, walnuts, and a few other foods contain omega-3s, but they're in the form of ALA; ALA must be converted into EPA, which is necessary for the production of certain hormones, and DHA, which is required for brain development, vision, and other functions. But the body generally uses ALA for energy, and conversion into EPA and DHA may be limited and inefficient for therapeutic purposes. Conversion efficiency depends on the individual, and varies widely; in most studies, conversion from ALA to EPA/DHA has ranged from 10 percent to 35 percent. What that means for you: if you're counting on flax and walnuts for your main source of omega-3 fats, take into account the fact that not all of it will be converted; a tablespoon of flaxseed oil is generally recommended.

In addition to flax and walnut, there are two exciting vegetarian EFA options you'll want to try — chia and salba seeds. Chia seed is an extremely rich source of omega-3s from ALA. Salba seed is another fantastic option for obtaining omega-3s from ALA as well as omega-6 fats. Each offers a multitude of benefits, including digestive health, and are versatile (e.g., can be used in recipes, sprinkled on food).

How many omega-3 fats should I eat every day? 

The vast body of research on omega-3 fats involves cardiovascular health; most studies suggest that omega-3s help prevent erratic heartbeats, lower blood pressure, improve blood vessel function, and lower triglyceride; at higher doses, omega-3 fats may also reduce chronic inflammation, which plays a role in the development of atherosclerosis. In addition, some research suggests that EPA and DHA from fish may help prevent prostate cancer. Most evidence supports dietary recommendations of 500 mg per day of EPA and DHA for cardiovascular disease prevention-about the equivalent of eating fish twice a week. A couple of points to remember: fish may contain mercury and other toxins, and improper processing and storage can damage the delicate oils, turning them rancid. If you take supplements, buy a high-quality version that's been stored properly and is tested to be free of contaminants.

What's all this about the balance between omega-3 and omega-6 fats? 

There's no question that omega-6 fats are necessary to health; however, the average American diet provides about 10 times more omega-6 oils, in the form of LA, than we need. That's because LA is found in processed foods and in common cooking oils, like cottonseed, safflower, corn, sunflower, and soybean oils. Many experts suggest that eating omega-6 fats in excess deprives us of the health benefits from omega-3 fats. Too many omega-6s relative to omega-3s can promote inflammation, and may increase the risk of dying from heart disease. One exception, GLA, an omega-6 fat found in evening primrose oil, may actually reduce inflammation.