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Quaiqu Ananse
22nd October 2011, 07:52 PM
Trans fats have a bad rap, but not all of them are harmful to your health. Learn the facts about this highly publicized fat so you can be a smart shopper

Just when you thought you understood trans fats (and to understand them is to avoid them like the plague, right?), new information surfaces showing that not all of these fats are bad. (Search: Good fats vs bad fats)

A recent review published in Advances in Nutrition suggests we reboot our thinking and labeling processes for trans fats, based on the fact that there are two different types of trans fats—synthetic, or industrial, trans fats and natural, or ruminant, trans fats—and the latter variety has shown to be harmless or potentially beneficial.

What’s the Difference?
The more ubiquitous and talked-about family of trans fats is referred to as industrial or synthetic trans fats. These are man-made and also known as partially hydrogenated oil. These are manufactured by bubbling hydrogen through fat at a high temperature in the absence of oxygen, thus preventing the fats from going rancid when they absorb oxygen and decomposing, which is what happens with unsaturated fats found in avocados and olive oil. The process also changes the molecular structure of the fat, turning the oil into a semisolid substance with about the same consistency as butter or shortening. Synthetic trans fats were initially introduced to minimize the amount of saturated fats we used. They also contain properties that preserve foods, prolong shelf life, and help with texture, so you’ll find them most often in cookies, cakes, shortenings, crackers, and dry food.

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It’s this family of trans fats that has been linked to increasing the risk of a number of chronic diseases, according to Spencer Proctor, one of the review authors and director of the Metabolic and Cardiovascular Diseases Laboratory at the University of Alberta in Canada. Synthetic trans fats have been shown to raise our bad cholesterol, lower our “good” cholesterol, increase inflammation, and possibly increase triglycerides. “All of these affect our heart and increase the risk of heart disease,” says Vandana Sheth, RD, CDE, spokesperson for the American Dietetic Association. They are also known to trigger inflammation and overactivity of the immune system, which may contribute to stroke, diabetes, and other chronic conditions in addition to cardiovascular issues.

Scientists are still unclear as to why trans fats raise our LDL levels, but one theory is that the addition of hydrogen to oil during the hydrogenation process might make it difficult for us to digest.

According to the USDA’s dietary guidelines, we should limit our synthetic trans fat consumption as much as possible. The American Heart Association has a more specific guideline. It suggests that trans fats should make up less than 1% of your total calories. So for a 2,000-calorie diet, you should consume no more than 2 g of trans fats daily.

The health risks were portrayed as so dire that a number of measures regulating its use have been taken. Cities, including Philadelphia and New York, banned its use in restaurants. California issued a partial statewide trans fat ban, and Kraft Foods reduced or eliminated trans fats in 650 products. “[Synthetic trans fat] is the family we’ve tried to remove from the food chain, and we’re doing quite a good job,” Proctor says.

Why Natural Trans Fats Aren’t as Bad
While the dangers of artificial and industrial trans fats are clear, the other family of trans fats, known as natural or ruminant trans fats, have been shown to have a neutral or potentially beneficial effect on our health. While researchers have known for some time that the two families of trans fats were different, they’ve come to better understand in the past few years the impact of vaccenic acid and conjugated linoleic acid (CLA)—the most prevalent natural trans fats.

Unlike synthetic trans fats, this other family of trans fats is found in nature, hence the name natural, or ruminant, trans fats, Specifically, they are produced in the rumen of cows and are made by the bacteria found in the animal. It’s contained in many dairy and beef products.

Research conducted over the past 2 years using animal model and cell culture studies have indicated that CLA, unlike its synthetic counterpart, might actually reduce the risk factors of heart disease, diabetes, inflammation, and obesity. In 2010, a study published in the American Journal of Clinical Nutrition examined CLA in overweight children for 7 months and found it had some potentially positive benefits on weight. In another 2010 study at the University of Alberta, a 3-week animal-model trial focusing on vaccenic acid showed that the substance lowered inflammation levels, which has important implications because inflammation is a leading risk factor of heart disease. Additional preclinical trials have also indicated that some natural trans fats lower lipid and cholesterol levels in the body, according to Proctor.

The recent review is the first of its kind to address key issues of benefit toward heart disease risk and cholesterol, and contains a broad spectrum of work, including epidemiological, preclinical, and clinical studies. Overall, scientists believe that natural trans fats have at least a neutral and not detrimental health effect, and are working on exploring the potential benefits with human clinical trials.

How to Be a Trans Fat–Savvy Shopper
So the place where we’re falling short, according to Proctor, is with labeling and informing consumers. Because labels don’t differentiate between the two trans fats, consumers might be misled when they see trans fat on the label of, for example, yogurt, which contains ruminant trans fats. (Video: Decode Food Labels)

Instead of relying on the nutrition label, start taking your cues from the ingredient list, suggests Sheth. “If a product’s ingredients include partially hydrogenated fat or oil, that’s a clue that the product has [synthetic] trans fats,” she says.

This is a good practice to enact for all foods—especially foods that boast having “0 trans fats.” By law, food items can have up to 0.5 g of trans fat per serving and can still use the term 0 trans fat, according to Sheth. “And it can really add up.” Again, to make sure you’re not overindulging in industrial trans fats, let the product’s ingredient list be your guide and steer clear of items with partially hydrogenated fat or oil.





Source: http://fitbie.msn.com/eat-right/truth-about-trans-fats?gt1=50002

Pope Bitterz D'Alomo
22nd October 2011, 08:27 PM
These days it's all about giving everything a bad name then come back later and say you didn't mean to.