How Fiber Protects Your Heart

Medically Reviewed by James Beckerman, MD, FACC on July 22, 2015
3 min read

Lisa Cimperman has a family history of high cholesterol and heart disease, so she knew she had to watch what she ate. But a few years ago she decided to take things a step further, when a routine test revealed that her cholesterol had crept up to 210 -- borderline high for a woman in her 30s who is otherwise pretty healthy.

Cimperman, a clinical dietician at University Hospitals Case Medical Center, replaced nearly all of the lean meat in her diet with fiber-rich beans, chickpeas, lentils, and legumes.

A year later her cholesterol level had dropped 30 points.

Her experience is far from unique. Several studies have shown that fiber you get naturally from food, as part of an overall healthy diet, can help to protect your ticker. It lowers cholesterol, reduces the risk of stroke and type 2 diabetes, and helps with weight loss.

There are two types of it: soluble and insoluble, although most fiber-rich foods contain some of both.

Fiber is also considered either "dietary" or "functional." The dietary kind is the indigestible part of plants that we eat, like fruits, vegetables, whole grains, beans, and nuts. You get it naturally in whole foods. The functional kind is extracted or made in a lab -- it's the type of fiber you’ll find in supplements or fiber-enriched foods.

Still, experts say you don't need to overthink it. They say it’s best to aim for a balanced diet rich with plenty of fiber-laden foods.

“It’s the whole pattern that seems to have the effect,” says Rachel Johnson, PhD, a professor of nutrition at the University of Vermont. “It’s hard to tease out exact foods. Food is a complex thing.”

Most people associate fiber with a healthy digestive system, but research has shown it can do a lot more than just keep you regular. Scientists are still working to figure out how exactly it works in the body, though. Some of the ways it helps your heart include:

Lowers cholesterol. Soluble fiber can reduce both "bad" LDL and overall cholesterol, perhaps by binding with cholesterol particles in your digestive system and moving them out of the body before they’re absorbed.

Protects against strokes and diabetes. Replace refined grains with fiber-rich whole grains in your diet, and you might lower the risk of a stroke by up to 36% and the risk of type 2 diabetes by up to 30%, research shows. Both conditions are tied to an increased risk of getting heart disease.

Lowers blood pressure. In another small study, researchers put 233 volunteers on a high-fiber diet that includes lots of whole wheat and whole oats. They found that after 12 weeks, participants had a drop in blood pressure and pulse pressure.

Encourages a healthy weight. Fiber can also be a weight loss weapon, because it gives you a feeling of fullness that helps stave off hunger.

All those benefits can add up to not just better heart health, but a longer life. In a 2011 study, researchers followed nearly 300,000 participants over 9 years. They found that eating lots of fiber was even linked to a lower risk of early death among men and women.

Women under 50 years old should try to get about 25 grams of fiber a day, and men should shoot for 38 grams.

Most Americans struggle to get enough, though. On average we get just 15 grams a day.

“I think it’s tough. I really do,” says cardiologist Suzanne Steinbaum, DO, the director of women's heart health at the Heart and Vascular Institute at Lenox Hill Hospital. “But I think it’s a crucial part of a heart-healthy diet.”

Cimperman, for one, is convinced. She often talks up the benefits of fiber when working with heart patients -- but as part of an overall healthy diet.

“I think it’s important to keep in mind that fiber is important," she says. But “understanding the big picture helps."