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Are Beans Bad for People with Rheumatoid Arthritis (RA)?


Rheumatoid arthritis (RA) is a debilitating autoimmune condition that develops when the body's immune system, which normally protects the body from invading microbes, does not recognize its own cells and attacks them as if they were hostile intruders, causing swelling and pain in the joints. In her New York Times bestselling book, The Paleo Approach, scientist Sarah Ballantyne presents her Paleo Autoimmune Protocol, or Paleo AIP, a relatively strict diet plan supposed to help people with autoimmune conditions, such as rheumatoid arthritis, to put their condition into remission. Like other Paleo-based dietary regimens, this diet requires avoidance of beans and other legumes because of the anti-nutrients they contain.

Below, we take a look at why Paleo folks believe that legumes such as beans might be bad for people with autoimmune conditions such as rheumatoid arthritis, but also explain why the notion that beans are bad for arthritis sufferers is not accepted by every expert.

Arthritis and Anti-Nutrients in Beans

Saponins are anti-nutrients that are found in a wide range of plants, ranging from nightshade vegetables such as tomatoes and potatoes to legumes such as beans and lentils. The purpose of saponins is to defend plants against attacks by insects by dissolving their cell membranes, but proponents of the Paleolithic diet maintain that some saponins, particularly those found in dry beans and nightshade vegetables, may be noxious not only to insects but also to people because of the potential of saponins to damage the gut wall due to their soap-like properties. This may be particularly problematic for autoimmune patients many of whom are believed to suffer from, or have an increased risk of developing, a condition called "leaky gut". The concept of leaky gut is somewhat controversial, but its existence is widely recognized in the Paleo community.

In people with a leaky gut, the intestinal barrier is damaged and substances that would normally stay in the gut can escape into the bloodstream. This in turn can agitate the immune system and cause chronic inflammation, something you definitely don't want if you suffer from an inflammatory autoimmune disease such as rheumatoid arthritis.

Along with saponins, beans also contain lectins, another class of anti-nutrients that can act as powerful natural insecticides. While some lectins appear to be completely harmless to humans, others have properties that make them problematic. Agglutinins, which are abundant in beans (particularly raw beans), are an example of a problematic group of lectins. If ingested in large enough amounts, they can be extremely toxic, but some experts believe even the tiny amounts of lectins found in cooked beans may cause problems in genetically susceptible people, setting the stage for the same leaky gut and autoimmune responses as saponins.

The Other Side of the Story

While the theory linking bean anti-nutrients and autoimmune diseases such as rheumatoid arthritis seems plausible, actual research in this area is still in its infancy. And, almost everything we currently know about the activities of saponins and lectins is based on laboratory studies, not on studies involving actual human beings.

It is also important to keep in mind that the lectin content of beans varies depending on cultivar, location and processing methods used after harvesting, which is relevant since the harmful effects of lectins are believed to be dose-dependent. Plus, cooking destroys bean lectins as long as you cook your beans long enough and at a high enough temperature (though some proponents of the leaky gut theory will argue that certain individuals might react even to the residual amounts of lectins that may be present in cooked beans).

What's more, research shows that beans have anti-inflammatory properties in vitro. One study found that hull extracts of the common bean were able to inhibit the pro-inflammatory mediators COX 1 and COX 2, an effect that was attributed to their antioxidant properties. Among the tested four bean varieties (black, pink, pinto and Great Northern), this effect was most pronounced in black bean hulls which exerted even stronger COX-inhibiting effects than aspirin. In addition, another laboratory study found that protein hydrolysates derived from beans were capable of suppressing the NF-κB pathway, which is a considered a prototypical pro-inflammatory signaling pathway, largely based on the role the NF-κB protein complex plays in the expression of pro-inflammatory genes such as cytokines, chemokines and adhesion molecules (2, 3).

Finally, some studies have actually found an inverse association between rheumatoid arthritis and bean-rich eating plans such as the Mediterranean diet. For example, a single-center, randomized, parallel study published in the March 2003 issue of the Annals of the Rheumatic Diseases found that adherence to a Mediterranean-style diet improved arthritis symptoms, reduced inflammation and improved vitality in people with well-controlled, yet active rheumatoid arthritis. By comparison, no relief was reported by controls who followed a typical Western diet. Also a study published in the September 2007 issue of the same journal found that a switch to a Mediterranean-style diet characterized by a high intake of fruit, vegetables, legumes and monounsaturated fat (in relation to saturated fat) reduced pain and morning stiffness arthritis patients.

Closing Thoughts

So, the bottom line is, although there are arguments both for and against the inclusion of beans in anti-arthritis diets, there is not enough hard evidence one way or another. Of course, if you suffer from rheumatoid arthritis, you can always experiment with a bean-free diet to see if it makes you feel better (just make sure you get enough protein from other foods if you stop eating beans). And, for those who want to keep eating beans, make sure you always prepare and cook them properly, which means pre-soaking them and cooking them thoroughly in clean boiling water or in a pressure cooker.

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15. G. McKellar et al (2007). A pilot study of a Mediterranean-type diet intervention in female patients with rheumatoid arthritis living in areas of social deprivation in Glasgow. Annals of the Rheumatic Diseases, 66(9):1239-43.
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Book You May Like
Book on Arthritis and Diet This science-based all-in-one guide by registered dietitian Kim Arrey and practising rheumatologist Dr. Michael Starr explains how specific medications, nutritional supplements, foods, and lifestyle factors affect the pain and inflammation associated with rheumatoid arthritis. Packed with invaluable tips and tasty anti-inflammatory recipes and sample menus, this meticulously-researched guide and cookbook is a must-have for all RA-sufferers. To learn more, or to order a copy from your local Amazon store, click here.