High Fiber Diet is the Simplest Way to Protect against Food Allergy

According to recent study presented in the journal Cell Reports, a high fiber diet rich in vitamin A may modify gut bacteria in such a way that could prevent or reverse food allergies.

It is approximated that about 15 million individuals in the United States have food allergies, and this number is growing.

In accordance with the Centers for Disease Control and Prevention (CDC), between 1997-2007, the number of kids and adolescents in the U.S. with food allergies increased by about 18 %, though the causes for this are not clear.

8 food types account for about 90 % of all food allergies. These are egg, fish, milk, peanuts,  shellfish, soy, tree nuts and wheat.

Allergic reactions to food differ from one person to another, but they may involve diarrhea, hives, nausea or vomiting, stomach pain and tingling or itching in the mouth.

In more serious cases, an individual with a food allergy may experience swelling of the lips, tongue, and/or throat, difficulty breathing, problems in swallowing, pain in the chest, and a sudden fall in blood pressure.

Occurrence of severe symptoms – alone or together with milder ones – could be signs of anaphylaxis, a possibly life-threatening reaction that needs quick medical attention.

Of course, the most effective way to prevent an allergic reaction to food is to avoid taking the food that causes it, though this can be simpler said than done.

Now, a new research recommends there may be a easy way to prevent or reverse food allergies: a high-fiber diet, rich with vitamin A.

Fiber triggers short-chain fatty acid production to decrease food allergy

Co-senior author Laurence Macia and colleagues came to their conclusion after examining mice that were artificially bred to be allergic to peanuts.

The investigators given some of the mice a high fiber diet rich in vitamin A – found in many fruits and vegetables – while others were given a diet with average fiber, sugar, and calorie content (the controls).

They identified that the mice provided the high-fiber diet had less serious allergic reactions to peanuts than mice fed the control diet.

On closer analysis, the investigators identified that the high-fiber diet altered the gut bacteria of mice, which secured them against allergic reactions to peanuts.

Next, the investigators had taken some altered gut bacteria from mice given the high-fiber diet and transferred it to the guts of mice with a peanut allergy that were “germ-free” – that is, they had no gut microbes.

Although these germ-free mice were not provided a high-fiber diet, the team identified that the addition of the altered gut bacteria secured them against allergic reactions to peanuts.

The investigators describe that gut bacteria break-down dietary fiber into short-chain fatty acids.

In their research, the team discovered that enhanced levels of these fatty acids work with the body’s immune system, preventing dendritic cells – which manage food allergies – from triggering an allergic reaction. Vitamin A is also essential for dendritic cell regulation.

Their results were supported when the team gave the allergic mice water rich with short-chain fatty acids for 3 weeks, prior to subjecting them to peanuts. Their allergic response was decreased.

Overall, the investigators say their results suggest that a diet low in fiber could be driving food allergies, and that adopting a high-fiber diet – rich with vitamin A – could be approach to reduced food allergy risk.

Concluding this Co-senior author Prof. Charles Mackay said,

“It’s probably that in comparison to our ancestors, we’re eating unbelievable amounts of fat and sugar, and just not enough fiber.

These results may be showing us that we require that high-fiber consumption, not just to avoid food allergy, but probably other inflammatory problems as well.”