Polyunsaturated fats are divided into two main families: omega-3s and omega-6s. Each of these includes a fatty acid essential to health.

1. Omega-3 fatty acids include alpha-linoleic acid, found in plants, and DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), found in fish.

• What they do in your body: Omega-3s, especially those found in fish, may help decrease blood clotting, decrease abnormal heart rhythms, reduce triglycerides (a type of fat molecule in the blood), and promote normal blood pressure. Your body can convert a small amount of the plant omega-3s you eat into the type of omega-3s found in fish. There's also evidence that plant omega-3s lower the risk of heart disease in their own right. To reduce the risk of inflammatory diseases, some researchers suggest getting more omega-3 fats and fewer omega-6s. Scientists are studying whether omega 3 fatty acids may help lower cancer risk.
• Bottom line: These are the good guys, folks! Choose cooking and table fats that will increase your intake of omega-3s.

2. Omega-6 fatty acids include linoleic acid, the major omega-6 found in food.

• What they do in your body: Studies show that omega-6s can reduce both total cholesterol and "bad" cholesterol when they replace saturated fat in the diet. But too much may cause health problems. Omega-6s may slightly decrease "good" cholesterol levels, compared with monounsaturated fats. And they can spur the production of hormone-like substances called eicosanoids that can lead to inflammation and damaged blood vessels. Further, excessive omega-6s can interfere with your body's conversion of plant omega-3s to the more powerful type of omega-3s usually found in fish.
• Bottom line: These are better fats than the saturated or trans fats, and some are essential to the body. They can also lower heart disease risk when they replace saturated or trans fats in your diet. But eating excessive amounts is not a good idea.

Rating the Fats

I took a nutritional look at 22 types of fats and oils (listed in order from the lowest amount of saturated fat to the highest): canola oil, Eden Organic safflower oil, hazelnut oil, almond oil Take Control, Benecol spread, grapeseed oil, Land O' Lakes Fresh Buttery Taste Spread, Shedds Spread Country Crock, olive oil, soybean oil, Canola Harvest Premium Margarine, peanut oil, soybean margarine (hard), Smart Balance Omega Plus** Buttery Spread, Smart Balance Buttery Spread, Crisco shortening, chicken fat, lard, butter, palm kernel oil, and coconut oil.

After tallying the calories, fat, saturated fat, monounsaturated fats, polyunsaturated fats, trans fats, omega-3 fatty acids, omega-6 fatty acids, and Vitamin E for all these products, here's the story the numbers told:

The top five sources of beneficial monounsaturated fats are:

1.Olive oil
2. Hazelnut oil
3. Eden Organic Safflower Oil
4. Almond oil
5. Canola oil

The top sources of beneficial plant omega-3s are, by far:

1. Canola oil
2. Soybean oil
3. Smart Balance Omega Plus Buttery Spread

The three oils with the most omega-6s (which are essential but which we tend to get too much of) are:

1. Grapeseed oil
2. Soybean oil
3. Peanut oil

The 10 oils/cooking fats lowest in saturated fat, contributing 2 grams or less per tablespoon, are:

1. Canola oil
2. Eden Organic Safflower oil
3. Hazelnut oil
4. Almond oil
5. Take Control Spread
6. Benecol Spread
7. Grapeseed oil
8. Land O' Lakes Fresh Buttery Taste Spread
9. Shedds Spread Country Crock
10. Olive oil

Putting It All Together

The bottom line is that it makes nutritional sense to focus on fats that have the least amounts of saturated fat and trans fat but higher amounts of omega-3s and monounsaturated fats.

When you do this, you end up with:

• Canola oil for most of your cooking (because it contains the lowest amount of saturated fat, it's the fifth highest in monounsaturated fat, and it contains the most omega-3s)
• Olive oil when it works in the recipe (because it contains the most monounsaturated fat; very little saturated fat; and, while it doesn't contain a lot of omega-3s, neither does it have a lot of omega-6s).
• A "better" margarine (such as Smart Balance Spread, Land O' Lakes Buttery Spread, or Take Control) for certain situations when that works best. They contain less fat than butter and little to no trans fats, may contribute some monounsaturated fats ... and, oh yeah, they taste pretty good, too!

Published March 18, 2004

SOURCES: The National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults: Final Report, September 2002. Arteriosclerosis, Thrombosis and Vascular Biology, July 2001. Journal of the American College of Nutrition, 1999; vol 18(3). American Journal of Clinical Nutrition, June 2001. Nutrition and Cancer, 2001; vol 39(2). Cancer Epidemiology Biomarkers and Prevention, September 1997. Environmental Nutrition, June 2003. ESHA Research Food Processor II nutrition analysis software, 2003.

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