Studies have shown that transfats can indeed be hazardous to human health, and many people have little to no idea how many common grocery and restaurant items contain high levels of them. The federal government now requires food producers to list the amount of transfats in their products, but the numbers alone mean little without additional education.
In the world of fats, there are several different subcategories based on saturation levels. Polyunsaturated fats are generally found in plant-based oils, and are generally considered healthy. Monounsaturated fats, such as olive oil, are also considered healthy in their natural state. Olive oil, for example, helps to lower the harmful LDL form of cholesterol. Many transfats begin as monounsaturated liquid fats, but become solid through a questionable process called hydrogenation. Hydrogen is actually bubbled through the oil until it becomes a solid fat product called margarine.
At the high end of the scale are animal fats considered saturated. Butter would be an example of a saturated fat product. While saturated fats are also considered to be hazardous in large amounts, they do not have the same effects as transfats, which actually raise the level of bad LDL cholesterol. This can raise a person's risk of heart disease significantly. They also have a negative effect on the body's blood sugar/insulin balance, which means diabetics who ingest high levels of transfats can suffer from insulin resistance.
Transfats were originally developed as an alternative to saturated fats such as animal lard or butter. Many saturated fats would turn rancid within a few days of purchase, and commercial food products made with real butter or lard would become stale quickly. Substances such as partially-hydrogenated vegetable shortening or margarine would extend the shelf life of commercial food products, as well as provide a cheaper alternative to butter or animal-based fats. They were often promoted as healthier than the artery-clogging saturated fats they replaced.
Not all of the dangers of transfats have been fully explored yet, but the studies released so far indicate that most should never have been approved for public consumption. According to a number of researchers, there is no acceptable level of this type of fat for the human body. There is simply no tangible health benefit associated with their consumption. In fact, some sources say thousands, if not millions, of human lives have been lost as a result of heart disease or diabetes aggravated by the accumulation of transfats.
In order to avoid these substances, consumers are urged to read labels before purchasing processed food products. The total amount of transfats per serving is now required to be listed on the label, but a number of food companies use alternative names to minimize the public's objections. One should look for ingredients such as partially-hydrogenated vegetable oil, margarine, or vegetable shortening. The closer to the top of the ingredients list those ingredients are, the more likely it is that they are found in large quantities in the food.
The safest bet to avoid transfats while shopping is to use the perimeter method. Concentrate on the natural or unprocessed foods generally found around the perimeter of a grocery store and limit excursions into the middle aisles filled with processed foods.