Transvetten slecht voor het hart.*
Dat
transvetten slecht zijn voor het hart is al langer bekend. Uit een Amerikaanse
analyse van gegevens uit de grote Nurses'
Health Study (hierin doen bijna 100.000 vrouwen mee) blijkt dat bij 2 gram
transvet per dag de kans op hart- en vaatziektes drie keer groter is dan met 1
gram transvet per dag. Zelfs bij 1 gram transvet is die kans trouwens
nog duidelijk aanwezig. Transvetten zitten in allerlei kant en klare producten
en bijv. frieten. In een portie friet kan wel 5 gram transvet zitten.
Trans
Fats Boost Heart Disease Risk
Trans fats have jumped out of the deep
fryer into a public grilling once again, with new research suggesting even small
amounts can harm the heart.
An analysis of data from the large Nurses' Health Study shows that women who ate
the most trans fats were more than three times as likely to develop heart
disease as those who consumed the least. The findings, presented at the annual
meeting of the American Heart Association (AHA), support recommendations to
avoid trans fat as much as possible, says researcher Qi Sun, M.D., of the
Harvard School of Public Health.
AHA President Ray Gibbons, MD, went further. The professor of medicine at the
Mayo Clinic in Rochester, Minn., says he supports a ban.
"There was no threshold below which they were safe," Sun says. But
"We saw a linear relationship: The more trans fats you consume, the worse
it is for your heart," he tells WebMD.
The report will no doubt please New York Mayor Michael Bloomberg, who has called
for a ban on the fats in that city.
Once praised for making crunchy foods crunchier and creamy foods creamier, trans
fats are in fact one of the most dangerous forms of fat.
Engineered from liquid oils through a process known as hydrogenation, they lurk
in most processed foods — including cookies, baked goods, popcorn, margarines,
shortenings, crackers, doughnuts, chips, frozen waffles, and french fries. You
can't get away from them.
Doctors have known for years that these fats can be damaging to the heart, but
the new study is one of the first to quantify just how harmful they are, Sun
says.
Also, the study was unique in that the researchers used trans fatty acid levels
in red blood cells as a marker of participants' trans fat intake. Past studies
used food questionnaires or food diaries, which depend upon people's often poor
recall, he says.
The Nurses Health Study is one of the longest-running major women's health
investigations ever undertaken.
In this research, Sun and colleagues looked at the trans fat consumption of 166
study participants who developed heart disease between 1989 and 1995, and 327
women who did not. The women were divided into four groups depending on their
trans fat consumption.
Those in the highest quartile — who consumed an average of 2.0 grams of trans
fats per 1,000 calories a day — were at highest risk for heart disease. But
even those eating just 1.3 grams per 1,000 calories per day were at increased
risk.
That's not much, when you consider that a typical serving of french fries has
about 5 grams of trans fats, a Danish has more than 3 grams, and even microwave
popcorn has 1.1 grams, Sun points out.
Eliminating such fats from your diet is a bit easier than in the past as the FDA
now requires all manufacturers to list the amount of artery-clogging trans fats
present in packaged foods.
But knowing how many were in that burrito you had for lunch is another story.
"We still don't know that any level of trans fats is OK," Gibbons
tells WebMD. "This study buttresses arguments to get rid of them."
Gibbons notes that in 2004, Denmark enacted legislation to eliminate
industrially produced trans fats from the food supply.
"While it took a lot of effort in the first few months, everyone seems
happy with their food now. And they're a whole lot healthier," Gibbons says.
SOURCES: American Heart Association's Scientific Sessions 2006, Nov. 12-15,
2006, Chicago. Qi Sun, M.D., Harvard School of Public Health, Boston. Ray
Gibbons, M.D.,, AHA president; professor of medicine, Mayo Clinic, Rochester,
Minn. Mozaffarian, D. The New England Journal of Medicine, April 13, 2006; Vol.
354: pp. 1601-1613.
(Nov. 2006) (Opm. Meer over transvetten.)