While some trans fatty acids (trans fats) occur naturally, most trans fats are the result of hydrogenation, a process that occurs during the production of commercial foods.
Once upon a time, only true diet detectives knew whether a particular food contained trans fat, a phantom fat added to thousands of foods that has the most damaging effects on the heart and blood vessels. They were the people who knew that the code phrases "partially hydrogenated vegetable oil" and "vegetable shortening" meant that trans fat lurked in the food.
As of January 1, 2006, trans fat must be listed on food labels along with other bad fats (saturated fats) and good ones (unsaturated fats).
The addition is a victory for Harvard School of Public Health researchers who helped sound the alarm about trans fat in the early 1990s and who advocated that it be explicitly listed on food labels. After much equivocation by the FDA and intense lobbying against adding trans fat to food labels by parts of the food industry, the FDA finally approved the addition.
This small, one-line change is sparking a major makeover of the American food supply. The FDA once estimated that approximately 95% of prepared cookies, 100% of crackers, and 80% of frozen breakfast products contained trans fat. Now that trans fat must be listed on food labels, some companies are scrambling to remove them from their products. Many others have already succeeded in going trans fat free. The shift follows the growing realization that trans fats are even worse for the heart and blood vessels than saturated fats.
Why is This Important to You?
Trans fats are a type of mostly man-made fat that the food industry loves, but our hearts and blood vessels don't. In the late 19th century, chemists discovered that they could turn liquid vegetable oil into a solid or semi-solid by adding hydrogen atoms to the fat backbone. They did this by bubbling hydrogen gas through vegetable oil in the presence of a nickel catalyst. This was far more than a chemical curiosity. Partially hydrogenated oils don't spoil as easily as nonhydrogenated fats. They can also withstand repeated heating without breaking down.
These characteristics were attractive to food makers. Over time, partially hydrogenated oils became a mainstay in margarines, commercially baked goods, and snack foods. When saturated fat was fingered as a contributor to high cholesterol, companies such as McDonalds and Dunkin Donuts switched from beef tallow to partially hydrogenated vegetable oil for frying French fries and donuts.
Today we know that eating trans fats increases levels of low-density lipoprotein (LDL, "bad" cholesterol), especially the small, dense LDL particles that are most damaging to arteries. LDL particles travel in the blood to specific sites where they attach with a type of lock and key mechanism, where they then unload their contents. Trans fats reduce LDL particle size, thereby reducing the particles surface area resulting in the loss of the receptor “key.” The particle can no longer attach to the specific sites and with nowhere to unload their contents they build up in our arteries.
It lowers levels of high-density lipoprotein (HDL) particles, which scour blood vessels for bad cholesterol and truck it to the liver for disposal. It increases the tendency of blood platelets to clump and form potentially artery-blocking clots. It also fires inflammation, an over-activity of the immune system that has been implicated in heart disease, stroke, diabetes, and other chronic conditions.
Now that the once-ubiquitous but invisible trans fats are listed in bold print on food labels, it's easier to spot them in packaged foods.
**Keep in mind, though, that according to the FDA, a product claiming to have zero trans fat can actually contain up to a half gram. (Canada set a different standard of zero as under 0.2 grams.) Some companies reduce the serving size on the ingredient label so they can claim that their product is “Trans Fat Free.” So you may still want to scan the ingredient list for "partially hydrogenated vegetable oil", "vegetable shortening" or “hydrogenated”’ and look for an alternative product without those words, especially if it's something you eat regularly. If you eat 2-3 servings you could be consuming up to 1.5 grams of trans fat, even though the label says “zero trans fat.”
It's harder to avoid trans fat in restaurants, since they are not required to provide nutrition information about the food they serve. One strategy is to avoid deep-fried foods, since many restaurants continue to use partially hydrogenated oils in their fryers. You may be able to help change this behavior by asking your server, the chef, or manager if the establishment uses trans-free oils.
Ounce for ounce, trans fats are far worse than saturated fats when it comes to heart disease. The Nurses' Health Study found that replacing only 30 calories (7 grams) of carbohydrates every day with 30 calories (4 grams) of trans fats nearly doubled the risk for heart disease. Saturated fats increased risk as well, but not nearly as much.
Action Plan
1. Look through your refrigerator and pantry at home. Scan the labels for the word ‘hydrogenated’ or “vegetable shortening.”
2. Make a list of these foods. When you grocery shop, be sure to find replacements for these foods that do not contain these words.
3. Stay vigilant. Continue to read labels, choosing foods that do not have the words ‘hydrogenated’ on the label.
4. Know where to shop. Trader Joes, PCC Markets and Whole Foods all have standards set for the foods that they stock. Trans fats are all but absent from these foods, making it easier to find both name and store brand foods to meet your needs.
If you find that most of the foods in your house contain these ingredients, don’t despair. If you can afford to, you can donate these foods to a food bank, take your list to the grocery store and replace them all at once. If not, simply start to replace them as you shop over the next few months.
This is how you really know how much trans fat is in your food.
Total fat minus saturated fat minus polyunsaturated fat minus monounsaturated fat = trans fat?
Example: Pringles Cheddar Cheese Chips
Total Fat: 9g
Saturated Fat: 3g
9g-3g = 6g (trans fat)
Example: Smart Balance Butter
Total Fat: 9g
Sat Fat: 2.5
Polyunsaturated Fat: 3.5
Monounsaturated Fat: 3g
9g - 2.5g - 3.5g - 3g = 0g (trans fat)
Under FDA guidelines, foods labeled "zero trans fat" can still have up to 0.49 g trans fat per serving
You should publish that mathematical equation
Posted by: SilverGST | June 10, 2011 at 08:35 AM