Fiber plays an important role in immune system function
By David Dunaief, M.D.
Autoimmune disease is an umbrella term that covers more than 80 different diseases (1). Among them are type 1 diabetes, lupus, rheumatoid arthritis (RA), psoriasis, multiple sclerosis, and inflammatory bowel disease. The common thread for all of them is that the body’s immune system is attacking organs, tissues and cells and causing chronic inflammation.
Unfortunately, autoimmune diseases tend to cluster (2). Once you have one, you are at high risk for acquiring others.
Typical medical protocols
Immunosuppressives are the “go-to” treatment for autoimmune issues. In RA, for example, a typical drug regimen includes TNF (tumor necrosis factor) alpha inhibitors, like Remicade (infliximab), and methotrexate. These therapies reduce underlying inflammation by suppressing the immune system and interfering with inflammatory factors. Disease-modifying anti-rheumatic drugs (DMARDs), a class that also includes Plaquenil (hydroxychloroquine), may slow or stop the progression of joint destruction and increase physical functioning.
There are several concerning factors with these treatments.
First, the side-effect profiles are substantial. They include risks for cancers, opportunistic infections and even death (3). Opportunistic infections include diseases like tuberculosis and invasive fungal infections.
It is no surprise that suppressing the immune system would increase the likelihood of infections. Nor is it surprising that cancer rates would increase, since the immune system helps fend off malignancies. One study showed that after 10 years of therapy, the risk of cancer increased by approximately fourfold with the use of immunosuppressives (4).
Second, these drugs were tested and approved using short-term clinical trials; however, many patients are prescribed these therapies for 20 or more years.
So, what other methods are available to treat autoimmune diseases?
Medical nutrition therapy
Medical nutrition therapy using bioactive compounds and supplementation are being studied. Medical nutrition therapy may have immunomodulatory (immune system regulation) effects on inflammatory factors and on gene expression.
Raising the level of beta-cryptoxanthin, a carotenoid bioactive food component, by a modest amount has a substantial impact in preventing RA. Several studies have also tested dietary interventions in RA treatment (5). Included were fasting followed by a vegetarian diet; a vegan diet; and a Mediterranean diet, among others. All mentioned here showed decreases in inflammatory markers, including c-reactive protein (CRP), and improvements in joint pain and other quality of life concerns.
What are the effects of fish oil?
Fish oil helps your immune system by reducing inflammation and improving your blood chemistry, affecting as many as 1,040 genes (6). In a randomized clinical study, 1.8 grams of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplementation had anti-inflammatory effects, suppressing cell signals and transcription factors (proteins involved with gene expression) that are pro-inflammatory.
In RA patients, fish oil helps suppress cartilage degradative enzymes, while also having an anti-inflammatory effect (7). A typical recommendation is to consume about 2 grams of EPA plus DHA to help regulate the immune system. Don’t take these high doses of fish oil without consulting your doctor, since fish oil can have blood-thinning effects.
Can probiotics help?
Approximately 70 percent of your immune system lives in your gut. Probiotics, by populating the gut with live beneficial microorganisms, have immune-modulating effects that decrease inflammation and thus are appropriate for autoimmune diseases. Lactobacillus salvirus and Bifidobacterium longum infantis are two strains that were shown to have positive effects (8, 9).
In a study with Crohn’s disease patients, L. casei and L. bulgaricus reduced the inflammatory factor TNF-alpha (10). To provide balance, I recommend probiotics with Lactobacillus to my patients, especially with autoimmune diseases that affect the intestines, like Crohn’s and ulcerative colitis.
Does fiber intake affect autoimmune disorders?
Fiber has been shown to modulate inflammation by reducing biomarkers, such as CRP. In two separate clinical trials, fiber either reduced or prevented high CRP in patients. In one randomized clinical trial, 30 grams, or about one ounce, of fiber daily from either dietary sources or supplements reduced CRP significantly compared to placebo (11).
In the second trial, which was observational, participants who consumed the highest amount of dietary fiber (greater than 19.5 grams) had reductions in a vast number of inflammatory factors, including CRP, interleukin-1 (IL-1), interleukin-6 (IL-6) and TNF-alpha (12).
Can diet substitute for medication?
Immune system regulation is complex and involves over 1,000 genes, as well as many biomarkers. Bioactive compounds found in high-nutrient foods and supplements can have a profound impact on your immune system’s regulation and may help reset the immune system. Even in severe cases, bioactive compounds in foods may work in tandem with medications to treat autoimmune diseases more effectively and help reduce dosing of some immunosuppressives, minimizing potential side-effects.
This is not hypothetical. I have seen these effects in my practice, where patients have been able to reduce — or even eliminate —immunosuppressives by altering their diets.
(1) niaid.nih.gov. (2) J Autoimmun. 2007;29(1):1. (3) epocrates.com. (4) J Rheumatol 1999;26(8):1705-1714. (5) Front Nutr. 2017; 4: 52. (6) Am J Clin Nutr. 2009 Aug;90(2):415-424. (7) Drugs. 2003;63(9):845-853. (8) Gut. 2003 Jul;52(7):975-980. (9) Antonie Van Leeuwenhoek 1999 Jul-Nov;76(1-4):279-292. (10) Gut. 2002;51(5):659. (11) Arch Intern Med. 2007;167(5):502-506. (12) Nutr Metab (Lond). 2010 May 13;7:42.
Dr. David Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com or consult your personal physician.