News / Health

Eating More 'Good' Fats Lowers Risk of Heart Disease

Reducing saturated fat in diet alone isn't enough, study says

People who eat more polyunsaturated fats have been found to have a lower risk of heart disease.
People who eat more polyunsaturated fats have been found to have a lower risk of heart disease.


Art Chimes

For years, doctors have been telling patients to cut down on saturated fats — the kinds of fats in meats and milk, for example. Reducing fat in the diet, especially saturated fat, was believed to be an important strategy to reduce heart disease.

Now, a new study says reducing fats isn't enough. We have to focus on the kinds of fats we eat.  

Previous studies found that people who ate a lot of saturated fats were more likely to have a lot of the kinds of cholesterol that can clog arteries and lead to heart attacks. But there was little direct evidence to show that cutting saturated fats actually lowered the risk of heart disease.

"And we wanted to look at whether replacing saturated fat with polyunsaturated fat, with a healthy fat rather than, for example, with carbohydrates or protein or other things, was beneficial," says Dr. Dariush Mozaffarian of the Harvard School of Public Health. He thought the answer might lie in the numerous studies over the years that looked at diet and heart disease.

"And so, we wanted to do a systematic review of all the literature, find all of the appropriate studies and pool them to see if together, there's a benefit for replacing saturated fat specifically with polyunsaturated fat."

So Mozaffarian and his colleagues studied the studies, eight of them, in which some participants ate less saturated fat and more polyunsaturated fats, the kind of fats that are in fish, nuts, and vegetable oils. They were compared with a control group that had more saturated fat in their diets.

This kind of research is called a meta-analysis. Often combining the results of several similar studies can produce conclusions that the individual studies don't support. Sometimes that's partly because combining studies increases the number of people participating in the research. In this case, the combined studies included more than 13,000 people.

Reducing saturated fats may reduce cholesterol, but low fat diets alone don't seem to do much to actually reduce clogged arteries and heart attacks.

"There's actually, in the last several years, been convincing evidence that replacing saturated fat in one's diet with carbohydrates has very little effect on heart disease. And so if that's not going to produce benefit, what sorts of replacements [for saturated fats] might?"

Mozaffarian's study found that people who replaced saturated fat with polyunsaturated fat had about a 20 percent lower risk of heart attack or other heart disease.

It's still not exactly clear how the polyunsaturated fats confer this benefit. But the researcher says their effect on cholesterol may be part of the answer.

"So for example, dietary fats also actually, in many cases, improve HDL cholesterol, the good cholesterol, compared to carbohydrates, and they actually lower triglycerides, a type of blood lipid which is associated with harm."

But Mozaffarian said dietary fats may also affect blood pressure and inflammation of the blood vessels; they may even have an impact on the heart's electrical function.

Whatever the mechanism, the study does suggest some guidance for people who want to lower their risk of heart disease.

"They can't just look at a product that says 'low grams of saturated fat' or 'low saturated fat' and assume that it's healthy," he said. "If you're taking out the saturated fat, what are you replacing it with?"

And it doesn't mean we have to spend a lot of time parsing the nutritional labeling that is now on packaged foods in many countries.

"If someone says I should eat fruits, vegetables, whole grains, fish, nuts, and avoid processed foods, sugary beverages, and foods with trans fats or high in salt, that's actually much simpler, I think, than chasing all of these numbers."

Professor Dariush Mozaffarian of Harvard School of Public Health. His study was published this week in the journal PLoS Medicine.

You May Like

Video Russia’s Syrian Escalation Tests Obama’s Crisis Response

Critics once again question whether president has been slow to act on Syrian conflict, thus creating opening for powers like Russia More

Ancient African DNA Shows Mass Migration Back Into Africa

First genetic analysis of ancient human remains in Africa suggests massive migration from north around time of Egyptian empire More

NASA: Pluto Has Blue Sky

New photos also reveal the presence of water ice More

This forum has been closed.
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Hungary Criticized for Handling of Refugeesi
Henry Ridgwell
October 08, 2015 8:02 PM
Amnesty International has accused Hungary of breaking multiple international and European human rights laws in its handling of the refugee crisis. As Henry Ridgwell reports, thousands of migrants and refugees continue to travel through the Balkans to Hungary every day.

Video Hungary Criticized for Handling of Refugees

Amnesty International has accused Hungary of breaking multiple international and European human rights laws in its handling of the refugee crisis. As Henry Ridgwell reports, thousands of migrants and refugees continue to travel through the Balkans to Hungary every day.

Video Iraqi-Kurdish Teachers Vow to Continue Protest

Sixteen people were injured when police used tear gas and rubber bullets to disperse teachers and other public employees who took to the streets in Iraq’s Kurdish north, demanding their salaries from the Kurdish Regional Government (KRG). VOA’s Dilshad Anwar, in Sulaimaniya, caught up with protesting teachers who say they have not been paid for three months. Parke Brewer narrates his report.

Video Syrian Village Community Faces Double Displacement in Lebanon

Driven by war from their village in southwestern Syria, a group of families found shelter in Lebanon, resettling en masse in a half-built university to form one of the biggest settlements of its kind in Lebanon. Three years later, however, they now face being kicked out and dispersed in a country where finding shelter as a refugee can be especially tough. John Owens has more for VOA from the city of Saida, also known as Sidon.

Video Bat Colony: Unusual Tourist Attraction in Texas

The action hero Batman might be everyone’s favorite but real bats hardly get that kind of adoration. Put more than a million of these creatures of the night together and it only evokes images of horror. Sarah Zaman visited the largest urban bat colony in North America to see just how well bat and human get along with each other.

Video Device Shows Promise of Stopping Motion Sickness

It’s a sickening feeling — the dizziness, nausea and vomiting that comes with motion sickness. But a device now being developed could stop motion sickness by suppressing certain signals in the brain. VOA’s Deborah Block reports.

Video Making a Mint

While apples, corn, and cranberries top the list of fall produce in the US, it’s also the time to harvest gum, candy, and toothpaste—or at least the oil that makes them minty fresh. Erika Celeste reports from South Bend, Indiana on the mint harvest.

Video Activists Decry Lagos Slum Demolition

Acting on a court order, authorities in Nigeria demolished a slum last month in the commercial capital, Lagos. But human rights activists say the order was illegal, and the community was razed to make way for a government housing project. Chris Stein has more from Lagos.

Video TPP Agreed, But Faces Stiff Opposition

President Barack Obama promoted the Trans-Pacific Partnership on Tuesday, one day after 12 Pacific Rim nations reached the free trade deal in Atlanta. The controversial pact that would involve about 40 percent of global trade still needs approval by lawmakers in respective countries. Zlatica Hoke reports Obama is facing strong opposition to the deal, including from members of his own party.

Video Ukranian Artist Portrays Putin in an Unusual Way

As Russian President Vladimir Putin was addressing the United Nations in New York last month, he was also being featured in an art exhibition in Washington. It’s not a flattering exhibit. It’s done by a Ukrainian artist in a unique medium. And its creator says it’s not only a work of art - it’s a political statement. VOA’s Tetiana Kharchenko has more.

Video Nano-tech Filter Cleans Dirty Water

Access to clean water is a problem for hundreds of millions of people around the world. Now, a scientist and chemical engineer in Tanzania (in East Africa) is working to change that by creating an innovative water filter that makes dirty water safe. VOA’s Deborah Block has the story.

Video Demand Rising for Organic Produce in Cambodia

In Cambodia, where rice has long been the main cash crop, farmers are being encouraged to turn to vegetables to satisfy the growing demand for locally produced organic farm products. Daniel de Carteret has more from Phnom Penh.

Video Botanists Grow Furniture, with Pruning Shears

For something a bit out of the ordinary to furnish your home, why not consider wooden chairs, crafted by nature, with a little help from some British botanists with an eye for design. VOA’s Jessica Berman reports.

VOA Blogs