3 August 2009   

Which oil should I cook with for better heart health? I get this question a lot. The short answer?  Whether it's corn, canola, olive, sunflower, or soy, they're all healthy. But some may give you more of a health boost than others.  

Why are most oils healthy?  All cooking oils are healthy because the fat in any liquid vegetable oil is going to be mostly "unsaturated". Unsaturated fats are liquid or soft at room temperature. Both polyunsaturated and monounsaturated fats are in this group.

Using unsaturated fats in place of more saturated fats can help you lower your total cholesterol and your LDL's. LDL's are the so-called "bad cholesterol" because they tend to stick to the sides of your blood vessels.  

Foods that are high in healthy unsaturated fats are:

  • Liquid vegetable oils
  • Avocadoes
  • Nuts and seeds
  • Olives
  • Soft tub or liquid margarines
  • Another health bonus of all vegetable oils is that they do not have any trans fats in them.  

    Firm fats can clog blood vessels.  The firmer a fat is at room temperature, the more saturated it is. Saturated fats can increase your blood cholesterol levels and clog your blood vessels.

       Foods that are high in saturated fat are:

  • Animal fats like bacon and lard
  • Butter
  • Whole milk and cheese
  • Stick margarine
  • Shortening
  • Vegetable oils are trans fat-free.  All vegetable oils are trans fat free.  Both saturated and trans fats appear when food producers make a solid fat from a liquid vegetable oil.  Think about corn oil margarine. It's made from liquid corn oil but it is firm and you can spread it on toast. The food manufacturer used a process called "partial hydrogenation" to make that liquid oil more solid. That's also how vegetable shortening, like Crisco, is made.

    But liquid vegetable oils don't go through this process of "partial hydrogenation" so they do not have any of the artery-clogging trans fats.  Many researchers think that trans fats may be just as bad for us as saturated fats - and maybe even worse!

    Omega 3 Fats.  Omega 3 fats are one of the polyunsaturated fats. We cannot make omega 3 fats in our bodies so we have to eat them in foods. Research shows that omega 3 fatty acids may lower your chances of getting heart disease, high blood pressure, and some cancers. They might also help with arthritis. Unfortunately, the typical American diet is low in this type of fat.

    Fish, walnuts, wheat germ, soybeans and some oils are high in omega 3 fats. Some vegetable oils are higher in omega 3 fats than others. Since we Americans often do not get enough of these healthy fats, it makes sense to choose a vegetable oil that's high in omega 3's.

     Oils highest in omega 3 fats:

  • Flaxseed oil
  • Canola oil
  • Walnut oil
  • Soybean oil
  •  Flaxseed and walnut oils can be very expensive.  But canola and soybean oils are inexpensive and just as healthy.

    Isn't olive oil one of the healthiest?  Liquid oils and other plant fats contain varying amounts of both polyunsaturated and monounsaturated fats. Both are considered "unsaturated". Some oils are higher in monounsaturated fats than others are. Olive, canola, and peanut oils are the highest. 

    Early research seemed to show that monounsaturated fats were healthier than polyunsaturated fats.  Recent research shows that either type is healthy and can help lower cholesterol. But if you want the best of both worlds, canola and soybean oils are the best choices because they're unsaturated and high in omega 3 fats. But olive oil is still very healthy.

    Taste and texture matter.   The taste of the oils should play a role in your buying and cooking decisions. Many people like to use olive oil in salad dressings and for sautéing vegetables because it has a tasty, distinctive flavor. It also makes an excellent alternative to butter - just put a little olive oil in a small dish and dip your bread. Canola and other vegetable oils have a blander flavor than olive oil. Their bland flavor makes them perfect for baking or any other time you don't want a strong flavor.

    And if you make pies and biscuits, you know that the more saturated fats like shortening make the flakiest piecrusts and biscuits. So sometimes, you just need to use the harder fats. And that's o.k. If you don't eat them too often and keep your portions small, you don't have to give up the foods you like.

    Will eating healthier fats help me lose weight?   It's important to know that all fats and oils have the same amount of calories. They add flavor to your meals and can help you to feel fuller so you may find you eat less. But be careful not to overdo them - or you may find your weight increasing.

    Beth Kitchin PhD RD
    Assistant Professor
    UAB Department of Nutrition Sciences