Which oils and fats are healthy and why?

Judging from all the fat-free and low-fat foods available, you might consider fat a dietary evil. However, the body needs a certain amount of fatty acids to function properly. Choosing the right type of dietary fat can mean the difference between health and disease.

 

The first question to ask: Is the fat solid or liquid?

 

“Limit solid fats such as butter, margarine, shortening or lard because they’re high in saturated fat and trans fat,” said Janet Hackert, nutrition specialist for University of Missouri Extension. “Saturated fat and trans fat are used by the body to make bad cholesterol.”

 

Polyunsaturated fats, which are liquid at room temperature, help to lower LDL, or “bad,” cholesterol in the body. They also include omega-6 and omega-3 fats that your body requires, but can’t produce on its own.

 

Vegetable oils such as soybean, canola and sunflower are often high in polyunsaturated fat, Hackert said. Corn and safflower oils are also good, inexpensive choices.

 

Flaxseed oil is the highest in polyunsaturated fat, at 75 percent. It’s also high in omega-3 fatty acids. However, flaxseed oil is unstable under certain conditions.

 

“Because it’s highly perishable, keep it refrigerated, and because it doesn’t handle the heat of cooking well it’s best used for adding its nutty flavor to salads and such,” Hackert said.

 

There are a few exceptions to the “liquid oils are better” rule.

 

“Coconut, palm and palm kernel oil are very high in saturated fat, ranging from 52 to 92 percent,” Hackert said.

 

Monounsaturated fat is a healthy choice too. Of the most common vegetable oils, olive oil has the highest level of monounsaturated fat. It also has a relatively high phenol content. Phenols are powerful antioxidants that remove body-damaging free radicals.

 

Olive oil’s processing method is an important consideration. According to Jeffrey B. Blumberg, director of the Antioxidants Research Laboratory at Tufts University, the methods of extraction and processing affect the phenolic content of olive oil. Blumberg advises that cold-pressed olive oil generally has the least loss of these important nutrients, Hackert said.

 

Fats and oils do carry a hefty calorie load, Hackert says. Every tablespoon of fat or oil contains about 90 calories. She recommends that you use them sparingly.