News / Health

Dietary Fiber May Prevent Asthma

A new study finds that soluble fiber, which comes from fruits and vegetables, may reduce inflammation in the lungs.
A new study finds that soluble fiber, which comes from fruits and vegetables, may reduce inflammation in the lungs.

Related Articles

Jessica Berman
Certain types of dietary fiber may be protective against asthma, a lung disease that until recently was largely unknown in the developing world.  Experts note the incidence of asthma is increasing in less developed countries, as people there shift their eating habits away from high-fiber foods in favor of processed ones.

We get two types of dietary fiber from food - insoluble and soluble. Insoluble fiber, from foods like whole grains, cucumbers and broccoli, includes so-called roughage, which helps cleanse the bowel.

A new study by researchers in Switzerland suggests that soluble fiber, which comes from fruits and vegetables, and is broken down by microbes in the intestines, may reduce inflammation in the lungs. 

Benjamin Marsland, an immunologist at the University of Lausanne, says that until recently, asthma was virtually unknown in nations where people eat a lot of soluble fiber.

“In some countries, Burkina Faso, for example, dietary fiber intake is very high and there is no development of allergies whereas in westernized countries we have an intake of dietary fiber is low and the allergies have been increasing,” Marsland said.

Gut bacteria break down soluble fiber, which includes pectin from apples, berries and citrus, into short chain fatty acids. Marsland says the fatty acids interact with spongy tissue inside the bones, where protective immune cells are produced, and help quiet immune system overactivity. An overzealous immune reaction can lead to inflammation.

To see whether dietary fiber could influence disease development outside the digestive tract, such as asthma, Marsland and colleagues studied two groups of rodents.  One group of mice had been fed a diet high in soluble fiber for two weeks while the other group was fed a diet low in pectin.

Both groups were then exposed to dust mites, a leading cause of asthma, a condition marked by lung inflammation, narrowing of the airways and wheezing.

Marsland says the mice that ate less soluble fiber had strong allergic reactions to the dust, including the presence of inflammatory compounds in the lungs and constricted airways similar to what’s seen in people.

The mice that consumed food rich in pectin, according to Marsland, had lower levels of the immune cells that are usually elevated in allergic asthma.

“So the mechanism through which diet is helping the lung is the dietary fiber changes the bacteria in our intestinal tract which changes the metabolites in our circulation and this is influencing how our immune cells develop,” he said.

Researchers confirmed their findings by injecting the mice with another short chain fatty acid.  Again, there were fewer inflammatory markers among rodents given the compound.

An article describing a link between soluble fiber and asthma is published in the journal Nature Medicine.

You May Like

At International AIDS Conference One Goal, Many Paths

The 12,000 delegates attending 20th International AIDS Conference in Melbourne have vastly different visions about how to eradicate disease More

Disasters May Doom Malaysia’s Flag Carrier

Even before loss of two jets loaded with passengers on international flights, company had been operating in red for three years, accumulating deficit of $1.3 billion More

Afghan Presidential Vote Audit Continues Despite Glitches

Process has been marred by walkouts by representatives of two competing candidates, Abdullah Abdullah and Ashraf Ghani More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Nature of Space Exploration Enters New Agei
X
Elizabeth Lee
July 20, 2014 2:36 AM
Forty-five years ago this month, the first humans walked on the moon. It was during an era of the space race between the United States and the Soviet Union. World politics have changed since then and -- as Elizabeth Lee reports -- so has the nature of space exploration.
Video

Video Nature of Space Exploration Enters New Age

Forty-five years ago this month, the first humans walked on the moon. It was during an era of the space race between the United States and the Soviet Union. World politics have changed since then and -- as Elizabeth Lee reports -- so has the nature of space exploration.
Video

Video Chicago’s Argonne Lab Developing Battery of the Future

In 2012, the U.S. Department of Energy’s Office of Science awarded a $120 million grant to a new technology center focused on battery development - headquartered at Argonne National Laboratory in suburban Chicago, Illinois. As VOA’s Kane Farabaugh reports, there scientists are making the next technological breakthroughs in energy storage.
Video

Video In NW Pakistan, Army Offensive Causes Massive Number of Displaced

Pakistan’s army offensive in North Waziristan has resulted in the large-scale displacement of the local population. VOA's Ayaz Gul reports from northwest Pakistan where authorities say around 80 percent of the estimated 1 million internally displaced persons [IDPs] have settled in Bannu district, while much of the remaining 20 percent are scattered in nearby cities.
Video

Video Kurdish Peshmerga Force Secures Kirkuk, Its Oil

The Kurdistan regional government has sent its Peshmerga troops into the adjacent province of Kirkuk to drive out insurgents, and to secure the area's rich oil fields. By doing this, the regional government has added a fourth province to the three it officially controls. The oil also provides revenue that could make an independent Kurdistan economically strong. VOA’s Jeffrey Young went out with the Peshmerga and filed this report.
Video

Video Malaysia Reeling: Second Air Disaster in Four Months

Malaysia is reeling from the second air disaster in four months involving the country’s flag carrier. Flight 340 vanished in March and despite an extensive search, no debris has been found. And on Thursday, Flight 17, likely hit by a surface-to-air missile, came apart over eastern Ukraine. The two incidents together have left more than 500 people dead. VOA Correspondent Steve Herman reports from Kuala Lumpur.
Video

Video Diplomatic Crisis Grows Over MH17 Plane Crash

The Malaysia Airlines crash in eastern Ukraine is drawing reaction from leaders around the world. With suspicions growing that a surface-to-air missile shot down the aircraft, there are increasing tensions in the international community over who is to blame. Henry Ridgwell reports for VOA from London.
Video

Video Undocumented Immigrants Face Perilous Journey to US, No Guarantees

Every day, hundreds of undocumented immigrants from Central America attempt the arduous journey through Mexico and turn themselves over to U.S. border patrol -- with the hope that they will not be turned away. But the dangers they face along the way are many, and as Ramon Taylor reports from the Rio Grande Valley in Texas, their fate rests on more than just the reception they get at the US border.
Video

Video Scientists Create Blackest Material Ever

Of all the black things in the universe only the infamous "black holes" are so black that not even a tiny amount of light can bounce back. But scientists have managed to create material almost as black, and it has enormous potential use. VOA’s George Putic has more.
Video

Video Fog Collector Transforming Maasai Water Harvesting in Kenya

The Maasai people of Kenya are known for their cattle-herding, nomadic lifestyle. But it's an existence that depends on access to adequate water for their herds and flocks. Lenny Ruvaga reports for VOA, on a "fog collector."

AppleAndroid