Are Beans Bad for Psoriasis Sufferers?
In her New York Times bestselling book, The Paleo Approach, Sarah Ballantyne (aka The Paleo Mom) presents a comprehensive Paleo-based diet and lifestyle plan supposed to help people with autoimmune diseases, such as psoriasis, to uncover food allergies and sensitivities, correct nutrient deficiencies and heal their gut. Known as the Paleo Autoimmune Protocol, or Paleo AIP, this diet plan requires avoidance of beans and other legumes because of the anti-nutrients they contain.
In this article, we take a look at the theory that explains why legumes like beans might be bad for people with autoimmune conditions such as psoriasis, but also explain why it may be too early to draw any conclusions about the effects of beans in people with psoriasis.
How Anti-Nutrients in Beans Could Promote Psoriasis
Saponins are complex compounds that occur naturally in a wide range of plants, including tomatoes, potatoes and legumes such as beans. In plants, saponins—which derive their name from their ability to create soap-like foams when mixed with water—ward off attacks by insects and microbes by dissolving their cell membranes. But many leading proponents of the Paleolithic diet, including Loren Cordain, the author of The Paleo Diet, believe that some saponins, particularly those found in beans, may be harmful not only to insects and microbes but also to people because of the potential of these soap-like compounds to create tiny holes in the gut lining, resulting in what Paleo folks call a "leaky gut". Along with other people with autoimmune diseases, people with psoriasis are believed to be particularly susceptible to developing a leaky gut.
The problem with a leaky gut is that it allows various undigested proteins and microbes to enter the bloodstream through the holes in the gut lining, which in turn stimulates the immune system and promotes chronic low level inflammation, something you definitely don't want if you suffer from an inflammatory autoimmune disease such as psoriasis.
To make matters worse, beans also contain lectins, another class of anti-nutrients that are thought to help prevent plants from being eaten by predators. While some lectins may be harmless to humans, others have properties that make them problematic. Agglutinins, which are abundant in beans, are an example of a problematic group of lectins. If ingested in large enough amounts, they can be highly toxic, but even small amounts might act as gut irritants in genetically susceptible people, setting the stage for the same leaky gut and autoimmune responses as saponins.
What You Should Know Before Drawing Any Conclusions
While the theory explaining how bean anti-nutrients might promote autoimmunity seems compelling, actual research in this area is still in the early stages. And, almost everything we currently know about the gut-irritating activities of saponins and lectins is based on test tube studies and animal studies, not on human studies.
It is also important to keep in mind that some beans contain more lectins and saponins than others, which is relevant since the harmful effects of lectins and saponins are believed to be dose-dependent. Plus, cooking destroys lectins as long as you cook them long enough and at a high enough temperature (though some Paleo folks might argue here that sensitive individuals might react even to the residual amounts of lectins that may be found in cooked beans).
Furthermore, according to a study that appeared in the June 2004 edition of the Journal of Agricultural and Food Chemistry, beans contain high levels of antioxidants, and some beans, such as red beans and pinto beans, were found to have even more in vitro antioxidant capacity than cultivated blueberries, artichoke hearts, blackberries and Red Delicious apples (which, as an aside, are among the healthiest apple varieties as measured by antioxidant capacity). Antioxidants have been researched for their ability to provide benefits for people with psoriasis, and although the results have been mixed, there is some evidence suggesting that antioxidants might offer some benefits for psoriasis sufferers.
Finally, some studies have actually found an inverse association between legume-rich eating plans such as the Mediterranean diet and autoimmunity. For example, an Italian study published in the January 2015 issue of the Journal of Translational Medicine found a link between adherence to the Mediterranean diet and a reduced risk of severe psoriasis flare-ups. And, not only that, but the PASI score and CRP levels, which were used to assess the severity of psoriasis in this study, were negatively correlated with the consumption of legumes, along with vegetables, fruit, extra-virgin olive oil, fish and nuts. And that is certainly an interesting observation, even though correlation does not necessarily mean causation.
So, the bottom line is, don't be too fast to jump on the Paleo bandwagon and think that beans are definitely bad for people with psoriasis. At this point, there is simply not enough scientific evidence to support the theory, and the same seems to hold true for any claims made about the potential health benefits of beans for psoriasis sufferers. Of course, if you suffer from psoriasis, you can always experiment with a bean-free diet to see if it reduces the severity of your flare-ups—just make sure you get enough protein from other foods in case you stop eating beans. And, for those who want to keep eating beans, make sure you always prepare and cook them properly, which means soaking them before cooking and then cooking them in clean boiling water or in a pressure cooker.
For More on Diet & Psoriasis
Make it a habit to visit HealWithFood.org's online Guide to Healing Psoriasis on a regular basis. Updated once a week, the sidebar on the home page of the guide contains tons of links to interesting nutrition-related articles hand-picked for psoriasis sufferers. It also contains a weekly smoothie recipe featuring ingredients with psoriasis-fighting potential, as well as a book tip. 
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Book You May Like
In her New York Times bestselling book, The Paleo Approach, Sarah Ballantyne draws upon cutting-edge research and her own battle with an autoimmune disease to provide you with a comprehensive Paleo-based diet and lifestyle plan for regulating the immune system and healing damaged tissues. Known as the Paleo Autoimmune Protocol, Ballantyne's groundbreaking plan emphasizes nutrient-dense foods and removes foods that promote inflammation and leaky gut syndrome. Also foods that stimulate the immune system are restricted on the AIP. In addition to explaining how eating certain foods and avoiding others can help put your condition into remission, this 400-plus page tome provides expert tips on how to "go Paleo" easily and economically. To learn more, or to order a copy, click here.
