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

Turkey: No Ransom Paid for Release of Hostages Held by IS Militants

President Erdogan hails release of hostages as diplomatic success but declines to be drawn on whether their release freed Ankara's hand to take more active stance against insurgents More

Audio Sierra Leone Ebola Lockdown May Be Extended

Lockdown, which started Friday, aims to allow health workers to locate hidden Ebola patients, educate others on how to avoid the deadly disease More

US Pivot to Asia Demands Delicate Balancing Act

As the tumult in the Middle East distracts Obama, shifting American focus eastward appears threatened More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Natural Gas Export Plan Divides Maryland Towni
X
Deborah Block
September 21, 2014 2:12 PM
A U.S. power company that has been importing natural gas now wants to export it. If approved, its plant in Lusby, Maryland, would likely be the first terminal on the United States East Coast to export liquefied natural gas from American pipelines. While some residents welcome the move because it will create jobs, others oppose it, saying the expansion could be a safety and environmental hazard. VOA’s Deborah Block examines the controversy.
Video

Video Natural Gas Export Plan Divides Maryland Town

A U.S. power company that has been importing natural gas now wants to export it. If approved, its plant in Lusby, Maryland, would likely be the first terminal on the United States East Coast to export liquefied natural gas from American pipelines. While some residents welcome the move because it will create jobs, others oppose it, saying the expansion could be a safety and environmental hazard. VOA’s Deborah Block examines the controversy.
Video

Video Fears Ebola Outbreak ‘Beyond Our Capability to Contain’

Each day brings with it new warnings about the deadly Ebola outbreak already blamed for killing more than 2,600 people across West Africa. And while countries and international organizations like the United Nations are starting to come through on promises of help for those most affected, the unprecedented speed with which the virus has spread is raising questions about the international response. VOA's Jeff Seldin has more from Washington.
Video

Video Difficult Tactical Battle Ahead Against IS Militants in Syria

The U.S. president has ordered the military to intensify its fight against the Islamic State, including in Syria. But how does the military conduct air strikes in a country that is not a U.S. ally? VOA correspondent Carla Babb reports from the Pentagon.
Video

Video Iran, World Powers Seek Progress in Nuclear Talks

Iran and the five permanent members of the U.N. Security Council plus Germany, known as the P5 + 1, have started a new round of talks on Iran's nuclear program. VOA State Department correspondent Pam Dockins reports that as the negotiations take place in New York, a U.S. envoy is questioning Iran's commitment to peaceful nuclear activity.
Video

Video Alibaba Shares Soar in First Day of Trading

China's biggest online retailer hit the market Friday -- with its share price soaring on the New York Stock Exchange. The shares were priced at $68, but trading stalled at the opening, as sellers held onto their shares, waiting for buyers to bid up the price. More on the world's biggest initial public offering from VOA’s Bernard Shusman in New York.
Video

Video Obama Goes to UN With Islamic State, Ebola on Agenda

President Obama goes to the United Nations General Assembly to rally nations to support a coalition against Islamic State militants in Iraq and Syria. He also will look for nations to back his plan to fight the Ebola virus in West Africa. As VOA White House correspondent Luis Ramirez reports, Obama’s efforts reflect new moves by the U.S. administration to take a leading role in addressing world crises.
Video

Video Migrants Caught in No-Man's Land Called Calais

The deaths of hundreds of migrants in the Mediterranean this week has only recast the spotlight on the perils of reaching Europe. And for those forunate enough to reach a place like Calais, France, only find that their problems aren't over. Lisa Bryant has the story.
Video

Video Westgate Siege Anniversary Brings Back Painful Memories

One year after it happened, the survivors of the terror attack on Nairobi's Westgate Shopping Mall still cannot shake the images of that tragic incident. For VOA, Mohammed Yusuf tells the story of victims still waiting for the answer to the question 'how could this happen?'
Video

Video Militant Assault in Syria Displaces Thousands of Kurds

A major assault by Islamic State militants on Kurds in Syria has sent a wave of new refugees to the Turkish border, where they were stopped by Turkish border security. Turkey is already hosting about 700,000 Syrian refugees who fled the civil war between the government and the opposition. But the government in Ankara has a history of strained relations with Turkey's Kurdish minority. Zlatica Hoke reports Turkey is asking for international help.
Video

Video Whaling Summit Votes to Uphold Ban on Japan Whale Hunt

The International Whaling Commission, meeting in Slovenia, has voted to uphold a court ruling banning Japan from hunting whales in the Antarctic Ocean. Conservationists hailed the ruling as a victory, but Tokyo says it will submit revised plans for a whale hunt in 2015. Henry Ridgwell reports from London.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid