Greater Dietary BCAA Intake Linked to Increased Risk of Rheumatoid Arthritis

Mohadeseh Soleimani Damaneh, MSc

Credit: Mohadeseh Soleimani on LinkedIn

Findings from a recent study are providing clinicians with valuable insight into diet’s potential influence on the risk of developing rheumatoid arthritis (RA), suggesting increased dietary branched-chain amino acid (BCAA) intake may be positively associated with RA risk.¹

Individual analyses of valine, leucine, and isoleucine intake revealed all 3 BCAAs were linked to a greater risk of RA, although there was no significant association between total and individual dietary BCAA intake and disease activity parameters, including disease activity score 28 (DAS-28), erythrocyte sedimentation rate (ESR), pain visual analog scale (VAS), morning stiffness, and the number of tender and swollen joints.¹

“The connection between branched-chain amino acids (BCAAs) and chronic diseases has recently received increasing attention,” Mohadeseh Soleimani Damaneh, MSc, of Iran University of Medical Sciences, and colleagues wrote.¹ “It has been reported that elevated plasma BCAA levels may be related to increased inflammation and oxidative stress levels, which are associated with the pathogenesis of different health conditions including RA.”

A growing body of research suggests diet and lifestyle play a sizeable role in influencing the risk and progression of various inflammatory illnesses, including RA. While some nutrients are known to combat inflammation, others have adverse effects on the development and progression of RA through the gut microbiota and body composition. The Mediterranean diet, vitamin D, and probiotics have all been suggested to confer protective benefits, but the role of BCAAs in RA development has not been thoroughly explored.²

To further investigate the association between dietary BCAAs and the risk and severity of RA, investigators conducted an age and gender-matched case-control study including consecutive patients with RA from a single rheumatology clinic and healthy controls. Adult patients 18-80 years of age who met the American College of Rheumatology criteria for a clinical diagnosis of RA by a rheumatologist were included in the study (n = 95).¹

For each case, investigators enrolled matched healthy controls from the companions of patients attending other departments within the same clinic in a 2:1 ratio. The inclusion criteria for patients in the control group were adults 18-80 years of age without joint or connective tissue disorders (n = 190).¹

Investigators assessed participants’ dietary BCAA intake using a 168-item semi-quantitative food frequency questionnaire. Individuals were asked to specify their frequency of consumption for each dietary component during face-to-face interviews conducted by an experienced dietician, listing them as daily, weekly, monthly, or yearly.¹

Daily intake of BCAAs was calculated for each participant by totaling their intake of leucine, isoleucine, and valine based on their usual consumption of foods containing these amino acids. Investigators also assessed disease severity using DAS-28, ESR, VAS, morning stiffness, and tender and swollen joints.¹

The mean age of the RA patients was 48.86 ± 9.41 years, and the mean age of the healthy controls was 47.46 ± 9.30 years. Female participants constituted 77.89% of the participants in both groups.¹

The total intake of BCAA was 16.86% total protein/day for the case group and 14.47% total protein/day for the control group. Investigators noted the percentage of total BCAAs, isoleucine, leucine, and valine intake was significantly higher in the RA group than in the control group (P <.001).¹

Upon analysis, greater BCAA intake, expressed as a percentage of total protein per day, was significantly associated with an increased risk of RA for total BCAAs (Odds ratio [OR], 2.14; 95% CI, 1.53-3.00; P <.001), leucine (OR, 2.40; 95% CI, 1.70-3.38; P <.001), isoleucine (OR, 2.04; 95% CI, 1.46-2.85; P <.001), and valine (OR, 1.87; 95% CI, 1.35-2.59; P <.001). Of note, these associations remained significant even after adjusting for potential confounders (P <.001).¹

Investigators did not observe any significant differences between ESR (P trend = .36), DAS28 (P trend = .84), VAS (P trend = .92), duration of early morning stiffness (P trend = .13), and the number of tender and swollen joints (P trend = .87 and P trend = .28, respectively) across tertiles of total BCAA intake.¹

“These findings suggest that a diet high in BCAAs may play a role in the development of RA. However, further studies are needed to investigate the potential roles of dietary BCAAs in RA and to confirm these findings,” investigators concluded.¹

References:

1. ^{Soleimani Damaneh M, Aryaeian N, Khajoenia S, et al. The association between dietary intake of branched-chain amino acids and odds and severity of rheumatoid arthritis. Sci Rep 14, 6309 (2024). https://doi.org/10.1038/s41598-024-56610-4}
2. ^{Shekhar KV, Pathak MM, Pisulkar G. Diet and Lifestyle Impact on Rheumatoid Arthritis: A Comprehensive Review. Cureus. 2023;15(11):e48625. doi:10.7759/cureus.48625}