Rheumatoid arthritis (RA), has been described as "a debilitating and frequently crippling autoimmune disease with overwhelming personal, social, and economic effects". (Mahan et al, 2011). In contrast to osteoarthritis, RA not only affects the membranes lining the joints, but also attacks interstitial tissues, blood vessels, cartilage, bone, tendons and ligaments.
An unknown disease
RA was very much an unknown disease, until recently, when it was discovered that it is an autoimmune condition where the defence systems of the human body actually start breaking down structures in the body they are supposed to protect. We still don’t know what triggers this destructive sequence of events, but genetic research has indicated that there are certain genes that play a role. It is generally believed that some viral or bacterial infection may trigger the severe inflammatory responses of RA (Mahan et al, 2011).
According to Krause (Mahan et al, 2011) and Ajeganova and coauthors (2012), RA is often linked to comorbidities such as heart disease, angina pectoris, hypertension, hyperglycaemia and/or diabetes, and chronic pulmonary disease, because of its inflammatory characteristics. Obesity has been associated with “worse RA-disease outcomes and higher prevalence of comorbidities”.(Ajeganova et al, 2012). In addition many of the medications that are used to combat RA such as anti-inflammatories (NSAIDs or non-steroidal anti-inflammatory drugs), and salicylates (aspirin), can cause negative side-effects including high blood pressure or bleeding ulcers. Daily intakes of aspirin increase the excretion of vitamin C by the kidneys often warranting ascorbic acid supplementation.
The so-called ‘Disease-modifying anti-rheumatic drugs (DMARDs)’, which are also used to treat RA, include sulfasalazine, hydroxychloroquine and methotrexate. DMARDs can cause myelosuppression, and damage to the macula of the eye and the liver. Methotrexate also affects folic acid metabolism which can result in anaemia and an increase in homocysteine, a marker chemical for heart disease. In addition, long-term therapy with methotrexate can cause neutropenia, mouth ulcers, nausea and vomiting, all of which may affect food and nutrient intakes (Mahan et al, 2011).
This serious effect associated with RA, leads to loss of body cell mass due to loss or deterioration of muscle tissue, the viscera and the immune system. Muscle weakness and loss of muscle function can in turn increase the morbidity and mortality of RA. Increased breakdown of protein may require higher protein intakes. The importance of appropriate exercises, tailored to the capabilities of each RA patient, to maintain muscle mass and function cannot be overemphasised.
Why RA patients need their dieticians
The reasons why I always advise patients suffering from RA who ask me for a general diet to alleviate their condition, to consult a registered dietician, are as follows:
Each RA patient requires an individual diet prescription to be worked out according to their specific needs, while taking the severity and stage of their illness (remission or flare-up), types of medications, comorbidities (obesity, diabetes, hypertension, heart disease) and level of activity into account.
Low-fat diets which may cause chronic deficiencies of vitamins A and E can lead to worsening of RA, so that self-selected slimming diets can be particularly harmful to these patients. Your dietician will provide guidelines for weight loss which do not deplete your fat-soluble vitamins, either by changing the type of fat used in the diet or supplementing with omega fatty acids and if necessary with fat-soluble vitamins at a controlled level.
Researchers have recently evaluated the usefulness and safety of popular dietary interventions used by patients suffering from RA. According to a meta-analysis of eight studies, conducted by Smedslund and co-authors (2010) in Norway, dietary manipulations such as the vegetarian, Mediterranean, elemental and elimination diets did not alleviate RA symptoms or progression. However, the study did find that most patients lost weight on these self-selected diets. Weight loss in RA may be desirable for some patients who are overweight or obese, but weight loss in those patients who are already suffering from rheumatoid cachexia, may be highly detrimental. So before you try out one of these popular alternate diets, please discuss them and their consequences with your dietician.
It is evident that the dietary treatment of RA is more complex than is generally believed and that patients can benefit greatly by being under the guidance of a registered dietician. Unfortunately, many RA patients are not referred to a dietician by their clinicians and consequently start experimenting with alternate diets, supplements and therapies which can in some cases exacerbate their condition and hasten deterioration.
What about supplements?
Patients who are seriously ill with a debilitating disease such as RA, naturally tend to turn to vitamin, mineral and other supplements in an attempt to alleviate their pain, discomfort and immobility. The most important rule to remember, if a vitamin, mineral or omega fatty acid supplement is either required (e.g. vitamin C when you are taking aspirin or folic acid during methotrexate treatment), or has provide some relief (e.g. omega-3 supplements), is that taking double or treble the amount of such a supplement will not be beneficial and can in fact be harmful (e.g. excessive intakes of vitamin A can cause hypervitaminosis A with side-effects such as liver damage, and have been linked to increased mortality).
Once again it is vital for you to only use nutrient supplements under the guidance of your dietician or when prescribed by your physician as is the case with folate that is generally dispensed with methotrexate.
Omega-3 fatty acids have been found to counteract the inflammatory process in many diseases, including osteoarthritis and RA. Both omega-6 polyunsaturated fatty acids (PUFA), like arachidonic acid (AA), and omega-3 PUFA, like eicosapentaenoic acid (EPA), are potent lipid mediator signalling molecules called “eicosanoids” that regulate inflammation. On the one hand, the eicosanoids produced in the body from omega-6 PUFA are pro-inflammatory, while on the other hand, omega-3 PUFA produce anti-inflammatory eicosanoids.
Because western diets have changed in such a way that we now tend to eat much less omega-3 PUFA than our ancestors (less fatty fish) and much more omega-6 PUFA (plant oils like sunflower, olive, or canola oils, which are also used in margarine), the so-called omega-6 to omega-3 ratio which used to be 3:1, is now as high as 15:1 or more. Some researchers blame this imbalance in the omega-6:omega-3 ratio for the upsurge in inflammatory conditions, including RA, cardiovascular disease, inflammatory bowel disease, Alzheimer’s disease and even obesity, which is classified by many present-day scientists as an inflammatory condition.
Increasing the ratio of omega-3: omega-6 in western diets preferably by eating omega-3 rich foods (fatty fish) and omega-3 enriched foods (eggs, bread, etc), or by taking omega-3 supplements (salmon oil capsules), may well counteract the overwhelming increase in inflammatory conditions, including RA (Patterson et al, 2012), that western populations are having to endure. Some scientists also suggest that marine bioactives containing omega-3 PUFAs, carotenoids, vitamins, minerals and/or peptides, are an untapped source of novel anti-inflammatory products (D/Orazio et al, 2012).
Hopefully future research may produce protective supplements that can also be used in RA. Please keep in mind that patients with an iodine sensitivity, or those that are allergic to fish or seafood, should not take supplements made from marine sources unless they are guaranteed to be free of iodine and/or allergens.
Patients with RA need the guidance of a registered dietician every step of the way when it comes to their standard diets, diets during flare-ups, diets to lose weight or conversely prevent weight loss and muscle degradation, the use of supplements that has to be tailored to disease progress and intake of medications, and selection of sensible diet options. So visit the Association for Dietetics in SA's website and click on "Find a Dietician" to find a dietician in your area. Discuss how you can boost your dietary omega-3 intake and the use of omega-3 supplements with your dietician. Keep as active as possible, but always check with your physician if the exercise you intend doing, is appropriate and will not harm your joints.
- (Dr IV van Heerden, DietDoc, July 2012)
(Ajeganova S et al (2012). Obesity is associated with worse disease severity in rheumatoid arthritis as well as with co-morbidities - a long-term follow-up from disease onset. Arthritis Care Research, 2012 April 18, [Epub ahead of print]; D’Orazio N et al (2012). Marine Bioactives: Pharmacological properties and potential applications against inflammatory diseases. Marine Drugs, Vol 10(4):812-33; Mahan LK et al (2011). Krause’s Food & the Nutrition Care Process. Ed. 13. Elsevier, USA; Patterson E et al (2012). Health implications of high dietary omega-6 polyunsaturated fatty acids. J Nutr Metab [Epub ahead of print]; Smedlund G et al (2010). Effectiveness and safety of dietary interventions for rheumatoid arthritis: a systematic review of randomized controlled trials. J American Dietetic Association, Vol 110(5):727-35)
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