Skip to content

Weight Loss & Diet Plans

Font Size

Trans Fats: The Science and the Risks

This man-made fat was developed to protect us against butter. Turns out, it acts like butter inside our bodies.

What Do Trans Fats Do Inside the Body? continued...

"The science that shows that trans fats increase LDL cholesterol levels is outstanding and very strong. All evidence is pointing in the same direction," Lichtenstein tells WebMD.

In the Nurse's Health Study, women who consumed the greatest amount of trans fats in their diet had a 50% higher risk of heart attack compared to women who consumed the least.

Some researchers suspect that trans fats also increase blood levels of two other artery-clogging compounds -- a fat-protein particle called lipoprotein(a) and blood fats called triglycerides.

Equally worrisome, population studies indicate that trans fats may raise the risk of diabetes. Researchers at the Harvard School of Public Health in Boston suggest that replacing trans fats in the diet with polyunsaturated fats (such as vegetable oils, salmon, etc.) can reduce diabetes risk by as much as 40%.

How much trans fat is safe? No one really knows. Kava says the prestigious Institute of Medicine reported that there isn't enough research yet to recommend a safe amount of trans fats. "We know that like saturated fats, trans fats can raise bad cholesterol, but there is conflicting data about what it does to good cholesterol," she says. "I wish the data were stronger."

The FDA, while requiring manufacturers to put the amount of trans fats on nutrition labels, will not require a percent daily value (DV) for trans fat because there is not enough information at this time to establish a such a value, she says. Food labels do offer such information about saturated fats.

How Do Trans Fats Compare to Saturated Fats?

"Trans fats raise (bad) LDL cholesterol levels slightly less than do saturated fats," says Lichtenstein. "But saturated fats also raise levels of high density lipoprotein (HDL) or "good" cholesterol, and trans fatty acids don't." Trans fats may actually lower HDL. Thus, some researchers say trans fats are worse. Lichtenstein, however, figures the two fats probably cause equal harm in our diets because we eat far more saturated fat than trans fats.

The FDA estimates that Americans adults eat 5.8 grams of trans fats per day -- that's about 2.6% of our daily calories. By comparison, we eat four to five times more saturated fat per day. About 40% of our trans fat intake comes from cakes, cookies, crackers, pies, and bread, while 17% comes from margarine.

Who Should Be Concerned About Trans Fats?

Of course, everyone should try to limit their consumption of trans fats and saturated fats. However, "individuals who are told by their physicians that they have elevated LDL cholesterol should be most concerned," Lichtenstein says. "They should minimize their intake of both trans fats and saturated fats."

Kava adds: "The most important thing is looking at the number of calories and then serving size. Then check out saturated fat and trans fat on the label. It might help some people make smarter decisions."

Today on WebMD

measuring waist
4 tips for shedding yours.
apple cider vinegar
Does it have health benefits?
 
Chocolate truffle
For weight loss, some aren’t so bad after all.
woman holding red dress
24 simple, practical tips.
 
woman shopping fresh produce
Video
butter curl on knife
Quiz
 
eating out healthy
Article
Smiling woman, red hair
Article
 
thumbnail_woman_tossing_spinach
Video
lunchbox
Article
 
What Girls Need To Know About Eating Disorders
Article
teen squeezing into jeans
fitfor Teens
 

Special Sections