Why are trans fats bad? Among other things, they cause heart disease, obesity and diabetes.

If you ask why are trans fats bad, the answer that you get depends on who you ask.

Some mainstream health authorities, including the Singapore Health Promotion Board, have only a few words to say - that trans fats raise the level of blood cholesterol.

They seem reluctant to list out all the possible reasons as to why are trans fats bad.

If you do some research on the Internet, however, you will uncover a long list of health problems associated with trans fats - heart disease, cancer, obesity, diabetes, infertility, miscarriage, and so on.

And the list of trans fat dangers keep getting longer as more research is conducted.

Previously, scientists did not even know what are trans fats and so they did not study the subject.

Many of the early research on saturated fats, for example, involved people who ate both saturated fats and trans fats. But when these people got sick, saturated fats were blamed.

Why are trans fats bad - cholesterol

To say that trans fats raise blood cholesterol is actually to tell only a small part of the story. In reality, it is much worse. As far as most scientists are concerned, there are two types of cholesterol:

high density lipoprotein (HDL) or "good" cholesterol
low density lipoprotein (LDL) or "bad" cholesterol.

Trans fats raise the "bad" cholesterol and, at the same time, lower the "good" cholesterol. So where cholesterol is concerned, there are TWO reasons as to why are trans fats bad. In contrast, saturated fats raise both types of cholesterol - the "bad" as well as the "good".

As discussed the articles about why cholesterol is not harmful and how is cholesterol healthy - high cholesterol in itself may not cause heart disease, although it may indicate the presence of heart disease (because both high cholesterol and heart disease may be caused by other factors.)

However, trans fats can directly cause heart disease in other ways:

Trans fats (as well as polyunsaturated fats that have turned rancid) damage artery walls, causing abnormal plaque build-up that eventually blocks the flow of blood.
Trans fats promote inflammation which, again, can damage artery walls and result in abnormal plaque build up. Inflammation, in turn, can cause artery walls to rupture. This could result in massive blood clots that obstruct the flow of blood, causing either a heart attack or a stroke. It could also result in massive loss of blood through internal bleeding, leading to death.
Trans fats inhibit the body’s use of omega-3 fatty acids and the production of long-chain omega-3 fatty acids – EPA and DHA, the types found to protect against heart disease. Again in contrast, saturated fats help the body to produce and use Omega 3.

Why are trans fats bad - Harvard studies

In an update on Trans Fatty Acids and Coronary Heart Disease, published in the New England Journal of Medicine (April 2006), Harvard researchers Waltre Willet and others wrote: The increase in risk of coronary heart disease caused by trans fat is higher than predicted by effects on blood lipids alone.

Back in 1994, Harvard researcher Walter Willett estimated that trans fats were responsible for at least 30,000 premature deaths from heart disease in the US each year.

In the 2006 update, that estimate has been revised upwards - to between 72,000 and 228,000 deaths that can be prevented by eliminating trans fats.

Why are trans fats bad - obesity

The latest research into why are trans fats bad tells us that not all calories are equal. And not all fats are equal either.

In May 2006, researchers at Wake Forest University reported that calories from trans fats made laboratory monkeys fatter than calories from other forms of fat. And this was in spite of efforts by the researchers to prevent the monkeys from gaining weight, by placing them on a low calorie diet.

The researchers also found that calories from trans fats made the monkeys much fatter around the tummy. In other words, trans fats re-distributed body fat, moving fat from other parts of the body to the abdomen area, thereby creating the “pear-shape” figure that has been strongly associated with heart disease, diabetes and other illnesses.

Lawrence Rudel, Ph.D., who headed the research, declared that the dangers of trans fats are worse than anticipated.

Other scientists are now saying that we need to re-think the whole idea that weight gain depends on calorie intake – because the latest study shows that even low calorie diets can produce weight gain if those calories come from trans fats.

Why are trans fats bad - Wake Forest University stury

The original aim of this study was to investigate the effects of trans fats on arterosclerosis, not on weight gain. Researchers fed 51 male vervet monkeys a western-style diet, which had 35 percent of their diet coming from fats. Half the monkeys got a lot of trans fat, totaling 8 percent of their total calorie intake. The other monkeys were fed unsaturated fats such as olive oil.

Both types of diets were calorie-controlled, as the researchers did not want the monkeys to put on weight. This was to ensure that whatever dangers of trans fats found during the research were due to trans fat intake, and not due to other factors such as weight gain.

So in theory, the monkeys should not have gained weight. But they did. Over six years -- equivalent to a 20-year span for humans -- the monkeys who ate unsaturated fats increased their body weight only marginally, by 1.8 percent. Monkeys that were given trans fats, however, put on 7.2 percent more weight.

Why are trans fats bad - diabetes

In the study cited above, a 7.2 percent weight gain may not seem much. But it is significant for two reasons:

The monkeys were not supposed to gain any weight in the first place as they were on calorie-restricted diets.
Even a 5 percent weight gain is enough to increase a person's risk of diseases like diabetes.

Said Dr Kylie Kavanagh, who reported the findings at the annual meeting of the American Diabetes Association in Washington: "In the world of diabetes, everybody knows that just 5 percent weight gain or weight loss makes an enormous difference. This little difference was biologically quite significant."

The monkeys that ate trans fats also had higher blood glucose levels and were more insulin resistant than the rest. In other words, the monkeys were showing early signs of Type II diabetes or adult-onset diabetes.

Why are trans fats bad - beer bellies

More significant than the 7.2 percent weight gain was the fact that the monkeys developed “beer bellies”, putting on much more weight around the tummy. Added Dr Kylie Kavanagh: “The trans-fat eaters also had about 33 percent more flab around their bellies. You can see white gobs of fat in these guys.”

The research at Wake Forest University School of Medicine on the dangers of trans fats has been named one of the top breakthroughs of 2006. The January 2007 issue of Discover magazine ranked it No. 14 among the most important scientific breakthroughs of the previous year.

Visit my other website, stop-trans-fats.com to discover even more reasons as to why are trans fats bad.