WASHINGTON–A plant-based diet may alleviate painful symptoms associated with rheumatoid arthritis (RA), according to a new review published in the journal Frontiers in Nutrition.

RA is an autoimmune disorder characterized by inflammation that causes pain and swelling. While genetic factors are important, studies show that lifestyle factors, including diet, play a role. Researchers with the Physicians Committee for Responsible Medicine reviewed clinical trials and observational studies and found strong and consistent evidence that a plant-based dietary pattern can reduce inflammation and improve symptoms associated with RA.

The study authors highlight four ways a plant-based diet may be effective:

1. Plant-based diets reduce inflammation. A 2015 study found that participants randomized to a two-month plant-based dietary intervention experienced reductions in inflammatory scores, when compared to those eating diets higher in fat and animal products. Other studies have found that diets high in fat and processed meat are associated with inflammatory markers, including C-reactive protein (CRP). Plant-based diets and high-fiber diets have been associated with lower CRP levels.

2. Plant-based diets reduce RA pain and swelling. A randomized clinical trial that looked at the effects of a low-fat vegan diet on people with moderate-to-severe RA found that after just four weeks on the diet, participants experienced significant improvements in morning stiffness, RA pain, joint tenderness, and joint swelling. The review authors suggest that plant-based diets are typically low in fat and high in fiber, which can reduce inflammation and decrease pain and swelling.

3. Plant-based diets are associated with a lower BMI. Studies show that excess body weight increases the risk for developing RA and decreases the likelihood of remission if RA is already present. A 2018 analysis found that RA patients who lost more than 5 kilograms of body weight were three times more likely to experience improvements than those who lost less than 5 kilograms. Plant-based diets have consistently proven to be effective for weight loss.

4. Plant-based diets promote healthy gut bacteria. Some studies suggest that the microbiome may play a key role in RA and inflammation. The authors note that high-fiber plant-based diets can alter the composition of gut bacteria and increase bacterial diversity, which is often lacking in RA patients.

“A plant-based diet comprised of fruits, vegetables, grains, and legumes may be tremendously helpful for those with rheumatoid arthritis,” says study co-author Hana Kahleova, MD, PhD, director of clinical research for the Physicians Committee. “This study offers hope that with a simple menu change, joint pain, swelling, and other painful symptoms may improve or even disappear.”

While more research is needed, the review adds to the evidence that diets rich in fruits, vegetables, whole grains, and legumes may be beneficial for autoimmune conditions. Other studies have found that a plant-based diet may be protective against hypothyroidism, hyperthyroidism, and multiple sclerosis.

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根据发表在《营养前沿》杂志上的一项新评论，以植物为基础的饮食可以减轻与类风湿关节炎（RA）相关的疼痛症状。

RA是一种自身免疫性疾病，其特征在于引起疼痛和肿胀的炎症。尽管遗传因素很重要，但研究表明，生活方式因素（包括饮食）起着一定作用。内科医师负责医学委员会的研究人员回顾了临床试验和观察性研究，发现有力且一致的证据表明，以植物为基础的饮食模式可以减少炎症并改善与RA相关的症状。

研究作者强调了植物性饮食可能有效的四种方式：

1.植物性饮食可减轻炎症。一项2015年的研究发现，与饮食中脂肪和动物产品含量较高的参与者相比，随机接受基于植物的两个月饮食干预的参与者的炎症评分降低。其他研究发现，高脂肪和加工肉的饮食与包括C反应蛋白（CRP）在内的炎症标记有关。植物性饮食和高纤维饮食与较低的CRP水平有关。

2.植物性饮食可减轻RA疼痛和肿胀。一项针对低脂纯素饮食对中度至重度RA患者的影响的随机临床试验发现，饮食仅4周后，参与者的早晨僵硬，RA疼痛，关节压痛和关节肿胀。该评价的作者认为，植物性饮食通常脂肪含量低而纤维含量高，可以减少炎症并减轻疼痛和肿胀。

3.植物性饮食与较低的BMI有关。研究表明，过重的体重会增加患RA的风险，并降低已经存在RA的症状缓解的可能性。 2018年的一项分析发现，体重减轻超过5公斤的RA患者经历改善的可能性是体重减轻少于5公斤的RA患者的三倍。植物性饮食一直被证明对减肥有效。

4.植物性饮食可促进健康的肠道细菌。一些研究表明，微生物组可能在RA和炎症中起关键作用。作者指出，高纤维植物性饮食可以改变肠道细菌的组成并增加细菌多样性，这在RA患者中通常是缺乏的。