|Nutrition Is Key To Combatting Your Autoimmune Disease|
|Wednesday, 25 January 2012 11:07|
Every day, your immune system protects you by attacking invaders such as bacteria and viruses. But when something goes awry with the body's immune system, immune cells may attack and damage tissues they were designed to protect, resulting in an autoimmune disease. Either the immune system mistakenly identifies healthy tissue as an invader and attacks it, or the immune system is unable to regulate its response.
About 8 percent of the U.S. population (three-quarters of this group are women ) are afflicted by one or more autoimmune diseases, according to the U.S. Centers for Disease Control and Prevention.
Autoimmune diseases may affect any part of the body. In type 1 diabetes, the immune system destroys the insulin-producing cells of the pancreas. In rheumatoid arthritis, it damages the membranes that line the joints, and in Crohn's disease, the immune system appears to overreact to normal intestinal bacteria and mount an overzealous attack. White blood cells then make their way into the lining of the intestines where they cause chronic inflammation.
Other commonly recognized autoimmune diseases include multiple sclerosis, celiac disease, ulcerative colitis and lupus. There are more than 80 known autoimmune diseases. Exactly what brings on an autoimmune disease remains a mystery, but scientists have found genetic links. However, genetics alone do not seal your fate--it's a combination of factors including environmental impacts, such as infections, toxins, drugs or diet.
LET THE SUNSHINE IN
Vitamin D, known as the sunshine vitamin because ultraviolet rays from the sun trigger its synthesis in the skin, may be one of those environmental factors that impacts autoimmune diseases. Scientists suspected that a lack of vitamin D plays a role in the development of autoimmune diseases when population studies showed that Crohn's disease, multiple sclerosis and other autoimmune diseases are more common in the northern U.S. and Europe than in southern areas where there's more sunlight. People who were born and lived the first 10 years of their lives in the south have a lower risk of developing multiple sclerosis throughout their lifetimes.
More evidence for vitamin D's role arose when researchers discovered that immune cells have vitamin D receptors that allow the vitamin to enter the cell, which suggests that vitamin D has a place there. Scientists also learned that patients with type 1 diabetes, Crohn's disease and lupus have lower blood levels of vitamin D than healthy individuals.
Additionally, in a 2008 issue of Arthritis Research and Therapy, Hungarian researchers reported that patients with early signs of, and at high risk for, rheumatoid arthritis and other autoimmune connective tissue diseases were more likely to convert to the full-blown disease if they had low blood levels of vitamin D.
Which came first: low levels of vitamin D or autoimmune disease? Scientists are still figuring this out, but Margherita T. Cantorna, Ph.D., professor of immunology and nutrition at Pennsylvania State University, suggests that vitamin D levels modify other risk factors that lead to autoimmune diseases. "If you don't have other risk factors (genetic and environmental) you won't get autoimmunity, even if vitamin D is very low," Cantorna says.
If you're at risk for developing autoimmune diseases because they run in your family, adequate vitamin D levels may slow or prevent the development of the disease, Cantorna adds. More research is necessary before scientists can definitively say that vitamin D supplements will affect autoimmune diseases in humans, though it may lessen the symptoms of multiple autoimmune diseases, she explains. It's wise to discuss vitamin D supplements with your physician if you are at risk for, or already have, an autoimmune disease.
Gluten, a protein in wheat, rye and barley, is an environmental trigger for the development of celiac disease, an autoimmune disease typically characterized by chronic diarrhea. For celiac disease to develop, an individual must consume gluten, be genetically susceptible to the disease, and have an unusually permeable intestinal wall that allows undigested food particles and other large molecules to pass into the bloodstream.
The only treatment for celiac disease is complete avoidance of gluten. When gluten is removed from the diet, the symptoms of the disease typically disappear until gluten is again consumed. Avoiding gluten is not the way to prevent the development of celiac disease, however, says registered dietitian Shelley Case, author of "Gluten-Free Diet, A Comprehensive Resource Guide." Research has revealed several factors related to the development of the disease. First, the baby has to have a genetic predisposition to the disease. Breastfeeding, the timing of first introduction of gluten, and the amount of gluten consumed early in life appear to play a role.
If your baby is at high risk for developing celiac disease due to a genetic predisposition, breastfeed for as long as possible, and introduce small amounts of gluten-containing cereals (about 1-2 teaspoons daily) between four and six months of age while still breastfeeding, she suggests.
Other dietary measures that decrease inflammation and promote healthy immune balance might also be advantageous for people with, or at risk for, developing autoimmune diseases, says Britt Burton-Freeman, Ph.D., director of the Center for Nutrition Research, Institute for Food Safety and Health, and associate research nutritionist at the University of California-Davis.
Shunning the typical American diet, which is high in calories, overly processed grains and saturated and trans fats, and instead eating a diet rich in fruits, vegetables, herbs, spices, fish and nuts, promotes healthy immune balance, she explains. These foods are rich in antioxidants, anti-inflammatory compounds and omega-3 fatty acids.
In a study published in a 2011 issue of the British Journal of Nutrition, Burton-Freeman showed that when overweight men and women consumed strawberries--a fruit rich in anti-inflammatory compounds--with a large, typical American breakfast, their inflammatory response was significantly lower than when they ate the same breakfast without the strawberries.
In another study conducted by Burton-Freeman's team, consuming tomato paste blocked inflammation from a high-fat meal in healthy, normal-weight men and women. According to findings announced at the Berry Health Benefits Symposium at Westlake Village, CA on June 28, 2011, whole, freeze-dried blueberry powder--high in anti-inflammatory compounds--reduced physical disability in mice with a form of multiple sclerosis.
THE BOTTOM LINE
The same diet recommended for the prevention of heart disease, stroke, diabetes, and other chronic illness--one rich in plants and low in animal fats and highly-processed foods--is the same one recommended to reduce the risk of autoimmune disease and manage an existing one. Look to foods that help prevent oxidation and inflammation.
Source: Tribune Media Services (2012), "Nutrition a key element in fighting autoimmune diseases"; Chicago Tribune