do beans cause gout

Do Beans Cause Gout?

A common question I hear is: “Do beans cause gout?” Several decades ago, apparently it was a common recommendation to avoid beans because of concerns over gout. However, we now have a much better understanding of the science, and guess what? Beans are NOT associated with an increased risk for gout. In fact, studies suggest that beans may even have a protective effect against gout.

Disclaimer: I am providing you with the most recent science I have found. However, please note that I am not a healthcare provider, and this is for informational purposes only. You should always seek the advice of a physician or other qualified healthcare provider with any questions regarding a medical condition or treatment.

Do beans cause gout

What is Gout?

Before we address whether beans cause gout, let’s clarify what exactly gout is. To explain gout, I referred to Mayo Clinic, Harvard Health, and several science articles I will reference later in this post.

Essentially, gout is a form of arthritis that can affect anyone, and the resulting acute inflammation in one or more joints – most often in the big toe – is very painful. The accumulation of urate crystals in the joint is the cause of the inflammation. Urate crystals can build up in the joint when uric acid levels in the blood are high. However, high concentrations of uric acid in the blood (i.e., hyperuricemia) do not always result in a gout attack. The body produces uric acid when it breaks down purines, substances found naturally in the body. Purines are also found in certain types of foods, including red meat, liver or other organ meats, and several types of seafood (e.g., anchovies, scallops). Sugary beverages and alcohol, especially beer, have also been found to result in higher levels of uric acid. Normally, uric acid passes through the body (i.e., leaves in the form of urine). But, if there is high production and/or the kidneys excrete too little, uric acid levels can build up, forming the urate crystals that cause pain and swelling.

There are several risk factors for gout – meaning factors that may make someone more likely to develop gout. These risk factors for gout include:

  • Diet. As previously mentioned, foods like red meat, certain seafood, sugary beverages (with high fructose levels), alcohol (especially beer), and others have been associated with an elevated risk for gout.
  • Weight. Being overweight can increase the risk of gout.
  • Gender. Males are at a higher risk for gout.

I want to focus on beans for this post. So, for more details about these and other risk factors, check out the gout article on Mayo Clinic, or the article by Harvard Health. But basically, here is the deal:

Years ago, the recommendation to prevent gout was to follow a purine-restricted diet. However, these diets are difficult to maintain and were not found to be very effective. Therefore, the current recommendation is to lose weight and reduce sugary beverage and alcohol intake, especially beer, and to reduce red meat and seafood intake for those who eat a lot of these foods. Yet, the older advice to restrict purines is still circulating, which begs the question: Do purine-rich vegetables, like beans, cause gout?

The Research on Beans and Gout

I want to share about four relevant studies that address the question: Do beans cause gout?

Study 1: Do Beans Cause Gout?

The first study I want to dive into is by Choi and colleagues (2004). The authors conducted a prospective study where they followed more than 47,000 men over 12 years. A prospective study means that researchers follow participants – who at study initiation do not have the outcome they are monitoring – over time and collect data about them to evaluate outcomes.

You can see the abstract of the paper below, or find the full paper here.

Beans do not cause gout - Choi et al 2004
Link to article: https://www.nejm.org/doi/full/10.1056/nejmoa035700

At the start of the study, the men had no history of gout, and the research team followed them over time to examine the relationship between purported dietary risk factors and the development of new cases of gout. What did the authors find? High levels of meat (in particular beef, pork, and lamb) and seafood consumption were associated with an increased risk of gout. But, total protein intake and the level of intake of purine-rich vegetables (including beans, lentils, and peas) was not associated with an increased risk for gout.

Interestingly, the results even suggested that protein from vegetable sources may have a protective effect against gout. The authors state, “Actually, our results regarding vegetable-protein intake suggest that protein from vegetable sources may have a protective effect.” You can see this in table 5 of the paper, where the group consuming the greatest amount of vegetable protein has a lower relative risk of gout than the group consuming the least amount of vegetable protein, and the effect was statistically significant. I have highlighted that below.

Beans and gout - Choi et al 2004 - relative risk
Source: https://www.nejm.org/doi/full/10.1056/nejmoa035700

What exactly is shown in this table? Let’s clarify some terminology first to make sure we are all on the same page. With relative risk (RR), having a relative risk of greater than 1 means there is an increased risk, whereas an RR of less than 1 represents a decreased risk. Having a relative risk of 0.73 means that the relative risk of the outcome – gout, in this case – is decreased by 27%. In other words, higher vegetable protein intake appears to reduce the risk of developing gout. The highlighted numbers you see next to the 0.73 in parentheses, (0.56-0.96), are the 95% confidence interval (CI). If a 95% CI includes the value of 1.00, then it is not considered to be a statistically significant finding. Now, this gets us into the space of “just because something is not statistically significant does not necessarily mean that it isn’t significant in real life,” but I’m not going to get (any further) into statistics here. The bottom line for now: the 0.73 (0.56-0.96) is a statistically significant finding, because the second number (0.96) is less than 1.00.

Summary of the Choi et al. 2004 paper: the level of intake of purine-rich vegetables (including beans, lentils, and peas) was not associated with an increased risk for gout, and vegetable protein may even be protective against gout.

Study 2: Do Beans Cause Gout?

Other research supports these findings that intake of vegetable protein does not cause gout. In the Shanghai Men’s Health Study conducted by Villegas and colleagues (2012), nearly 4,000 men aged 40 to 74 years were evaluated in a cross-sectional study. Cross-sectional studies analyze data from a population at a single point in time (as opposed to the aforementioned Choi et al. (2004) prospective study, which followed the participants over time). In this study, the research team investigated associations between high purine-content foods and protein intake with the prevalence of hyperuricemia (high levels of uric acid in the blood, which may lead to gout).

You can see the abstract of the paper below, or find the full paper here.

Beans do not cause gout - Villegas et al 2010
Link to article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3150417/

Summary of the Villegas et al. 2012 paper: No association was found between consumption of purine-rich vegetables and the prevalence of hyperuricemia. In fact, there appeared to be an inverse association between plant protein and hyperuricemia, meaning plant protein may help protect against hyperuricemia. However, the inverse association was not statistically significant.

Study 3: Do Beans Cause Gout?

Li and colleagues (2018) conducted a meta-analysis and systematic review, examining 19 studies to assess the impacts of diet on risk of gout and hyperuricemia. Meta-analyses can be very powerful because they combine several studies and analyze the overall results, in effect becoming a “super study” with greater statistical power and broader implications.

Below is the abstract of the paper, or find the full paper here.

Beans do not cause gout - Li et al 2018
Link to article: https://pubmed.ncbi.nlm.nih.gov/30485934/

In the Li et al. 2018 study, foods that were associated with an increased risk of hyperuricemia and gout included red meat, seafood, fructose, and alcohol. In contrast, intake of dairy products and soy foods correlated with a reduced risk for hyperuricemia and gout. No association was found between high purine-vegetables (which include beans, peas, and lentils) and hyperuricemia. Additionally, high-purine vegetables demonstrated a negative association with gout, meaning they were associated with a decreased risk for gout. The authors claim, “Our work verified that purine-rich vegetables intake was not correlated with gout risk, and further, was associated with lowered risk of hyperuricemia.”

Summary of the Li et al. 2018 paper: Once again, no association was found between consumption of purine-rich vegetables (e.g., beans, lentils) and the prevalence of hyperuricemia. Instead, purine-rich vegetables may help protect people from the risk of hyperuricemia and gout.

Study 4: Do Beans Cause Gout?

Okay, one last research article for now. This study by Becerra-Tomás and colleagues (2020) focused on non-soy legumes. Oilseed legumes like soy are different from non-oilseed legumes like pulses (read more about the different types of legumes here), so it makes sense to separate them. In this cross-sectional study, the authors assessed the consumption of non-soy legumes (e.g., chickpeas, beans, lentils), serum uric acid levels (i.e., uric acid levels in the blood), and hyperuricemia.

In addition to the abstract shown below, you can find the full article here.

Beans do not cause gout - Becerra-Tomas et al 2020
Link to article: https://pubmed.ncbi.nlm.nih.gov/31385063/

Summary of the Becerra-Tomás et al. 2020 paper: I think I’ll just leave it in the words of the authors for this one. “In this study of elderly subjects with metabolic syndrome, we observed that despite being a purine-rich food, non-soy legumes were inversely associated with SUA [serum uric acid] levels and hyperuricemia prevalence.”

Why Do Beans Not Cause Gout?

Why do scientists think there is a difference in the effects between different purine-rich foods? For one, there is somewhat limited knowledge on the actual level of purines in foods, especially after cooking or processing, which complicates things. Additionally, the bioavailability (i.e., amount the body can actually absorb) of purines may vary between different foods. For example, purines in animal-based foods may be more bioavailable to be processed and broken down into uric acid than the purines in plant-based foods. Thus, the purines in beans and other pulses (e.g., chickpeas, cowpeas, dry peas, lentils) may not have the same impact on raising uric acid levels as say, red meat. Moreover, pulses contain other components – like dietary polyphenols – that could help reduce levels of uric acid.

Summary: Beans Are Not Associated with Gout

As you can see, the research and current science supports that beans are not associated with an increased risk for gout. In summary…

  • Beans are not associated with an increased risk for gout. In fact, studies suggest that beans may even have a protective effect against gout. As in, eating beans may have the exact opposite effect folks are concerned about and actually be helping prevent gout!
  • There are dietary risk factors for gout, but vegetable protein intake is not one of them. Choosing plant proteins like beans is a good choice. Dietary risk factors associated with an increased risk for gout include high red meat, seafood, and alcohol consumption. This article on WedMD shares some foods to avoid if gout is a concern, as well as some foods to eat. As you may have guessed by now, beans, peas, and lentils are on the list of foods to eat.

References for Do Beans Cause Gout?

  1. Mayo Clinic. Gout. https://www.mayoclinic.org/diseases-conditions/gout/symptoms-causes/syc-20372897
  2. Harvard Health. All About Gout. 2023. https://www.health.harvard.edu/newsletter_article/all-about-gout
  3. Choi, Hyon K., et al. “Purine-rich foods, dairy and protein intake, and the risk of gout in men.” New England Journal of Medicine 350.11 (2004): 1093-1103. (https://www.nejm.org/doi/full/10.1056/nejmoa035700)
  4. Villegas, Raquel, et al. “Purine-rich foods, protein intake, and the prevalence of hyperuricemia: the Shanghai Men’s Health Study.” Nutrition, Metabolism and Cardiovascular Diseases 22.5 (2012): 409-416. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3150417/)
  5. Li, Rongrong, Kang Yu, and Chunwei Li. “Dietary factors and risk of gout and hyperuricemia: a meta-analysis and systematic review.” Asia Pacific Journal of Clinical Nutrition 27.6 (2018): 1344-1356. (https://pubmed.ncbi.nlm.nih.gov/30485934/)
  6. Becerra-Tomás, Nerea, et al. “Cross-sectional association between non-soy legume consumption, serum uric acid and hyperuricemia: the PREDIMED-Plus study.” European journal of nutrition 59 (2020): 2195-2206. (https://pubmed.ncbi.nlm.nih.gov/31385063/)
  7. WedMD. Best (and Worst) Foods for Gout. 2023. https://www.webmd.com/arthritis/ss/slideshow-gout-diet

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