Partially hydrogenated oils do not exist in nature. Partially hydrogenated fats and oils are processed versions of naturally occurring fats and oils.
Hydrogenated fat is solid or semi-solid at room temperatures. It is found in hard and semi-soft margarine and in vegetable shortenings. These fats are found in almost every processed food in the supermarket.
Hydrogenated fats are found in a vast range of products. Here are some commercial foods that are notoriously high in hydrogenated fats:
Without paying attention to what you buy, it is almost impossible to avoid consuming these fats.
Hydrogenated fats are saturated-like fats made from plant oils and fats that have been heated and pressure-processed. Hydrogenated fats are created when an oil that is largely unsaturated, such as corn oil, has hydrogen added to it, causing fat to become more solid at room temperature.
During hydrogenation, the unsaturated fat becomes more saturated – "artificially saturated."
Processed foods made with hydrogenated oils pose another (even worse) health hazard: trans fatty acids. These are chemically altered (processed) fats. You can find them in most packaged foods listed on the label as 'partially hydrogenated' or 'hydrogenated oil'. Our bodies have a more difficult time with processed foods and would prefer foods in their natural state.
The more solid and hydrogenated the fat, the more trans fatty acids there are in the product.
Why does the food industry use hydrogenated or partially hydrogenated fats in food products? Plain and simple reason: hydrogenation extends the supermarket shelf life of products. Cookies and chips, for example, take a lot longer to go rancid.
In nature, most dietary fats and oils exist in a structural form which is called the "cis" form. When these natural cis form fats are processed by bubbling hydrogen gas through them at high temperatures, they become partially hydrogenated which changes their structure to the "trans" form. The natural cis fat has a bend and the processed trans fat is a straight molecule.
This difference in cis and trans shapes is of major significance. When eaten, fats and oils are incorporated into cell membranes altering the composition of these delicate structures. When they interact with normal fat metabolism, trans fats interfere with important, normal functions by inhibiting enzymes which are necessary for the body's normal metabolism of fats and they keep doing it for a long time.
When you eat normal cis fats, the body metabolizes half of them in 18 days. When you eat trans fats the body requires 51 days to metabolize half of them. This means that half of the trans fats you eat today will still be inhibiting essential enzyme systems in your body 51 days from now.
A study of 80,000 women in the famous Harvard School of Public Health Nurses' study proved that the kind of fats a person eats is more important than the amount. In this study, women who consumed the most trans fats had a 53% greater chance of suffering a heart attack.
If the label contains the words "hydrogenated" or "partially hydrogenated", do not buy or eat it. It's really that simple. Terms like "vegetable oil" or "cholesterol free" tell you nothing about the amount of trans fat in the food. Healthy foods are far more likely to be found in... health food stores!
Look for newer labels, such as on some margarines, that proudly say "saturated-fat free" or "contains no trans fatty acids."
The principle of supply and demand suggests that if you demand less hydrogenated fat and more truthful labeling, food packagers will produce it.
Avoid deep-fried foods, especially those at fast-food restaurants. If you must indulge, come right out and ask if the fries are immersed in oils containing hydrogenated or trans fats. Don't settle for claims that the food is cooked in "100% vegetable oil." That label lie camouflages a lot of hydrogenated fat. Remember: The goal of fast-food chains is to create a taste that makes you want more. Besides being more economical, hydrogenated oils give food a fatty taste that makes you want to eat more.
Be suspicious of doughnuts from doughnut shops, since they don't come with nutrition labels. Inquire about the oil the donuts were fried in. You can bet donuts will continue to be high in saturated fats and trans fats unless consumers complain.
If you use margarine instead of butter, choose one that boasts low levels of trans or hydrogenated fats. In general, whipped or tub margarines tend to be lower in saturated and trans fats than sticks. Some products contain a blend of butter and vegetable oil to provide the consistency of margarine but with no trans fats.
The Swank diet includes strict avoidance of fried food and trans-fatty acids.