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Dietary recommendations for a diet based on healthy plant consumption have an inverse association between incident gout compared to those with unhealthy plant foods, according to recent findings presented at the American College of Rheumatology 2023 Convergence.¹

These findings align with current recommendations related to dietary habits, suggesting individuals should increase their plant food consumption and decrease their intake of unhealthy plant foods to lower their own risk of gout.

The expansion of plant-based diet popularity among many individuals is known by many to be connected to these diets’ strong results in improvement of cardiometabolic conditions and to environmental concerns.

Prior research on such diets and gout was viewed as limited due to its categorization of plant-based dietary habits into a simplistic "vegetarian" or "meat-containing" label, without considering the nuanced qualities of different kinds of plant-based foods.

To address this, a research team led by Sharan Rai of the Harvard TH Chan School of Public Health looked into the links between adherence to a plant-based diet—covering both healthy and unhealthy food variations—and 18 individual food group components, with the occurrence of incident gout.

Rai and colleagues assessed data derived from 123,014 subjects who had been enrolled in the Health Professionals Follow-up Study and Nurses’ Health Study, with each of these individuals having been initially free of gout. The team crafted an overall plant-based diet index (PDI), with both healthy (hPDI) and unhealthy (uPDI) versions.

The hPDI and uPDI versions were both designed by the investigators to prioritize either nutritious or less nutritious plant-based food products, respectively. The indices were made up of 18 food groups, and they were evaluated through a semi-quantitative food frequency questionnaire and a scoring system of 18 (lowest) - 90 (highest).

Biennial questionnaires were also given to subjects to self-report incidents of newly-diagnosed gout, and incident gout cases by confirming them through a supplementary questionnaire based on the preliminary American College of Rheumatology survey criteria for gout.

The investigators implemented Cox proportional hazards regression models to look into multivariable-adjusted links between all three PDIs and the occurrence of cases of gout.

Overall, the research team reported that their data indicated an inverse association between the hPDI and incident gout (pooled HR per 10-unit increase 0.89 [0.83, 0.95]). They added that the uPDI showed a positive association with gout (pooled HR per 10-unit increase 1.09 [1.02, 1.16]).

Comparable associations were also identified by the investigators over strata defined by overweight, status of hypertension, intake of dairy products, intake of fiber, and menopausal status, and there was no statistically significant data indicating effect modification.

That said, the team’s noted inverse association between gout and hPDI was found to have persisted among subjects that had notably lower levels of physical activity. These lower levels were notable as they were below the median level of physical activity, though significance was lost among those with noted higher physical activity levels.

The investigators found that the overall PDI, emphasizing consumption of all plant foods, indicated no link with gout risk. Interestingly, increases in intake of certain food products such as whole grain foods and tea/coffee were shown to be independently correlated with diminished risk of gout.

Conversely, there were specific unhealthy plant-based food products such as fruit juice and sugar-sweetened beverages that were found to have been positively associated with cases of gout.

References

1. ^{Rai S, Hu F, Wang M, Choi H, Sun Q. Plant-based Diet Quality and the Risk of Gout: Results from Two Prospective Cohort Studies of US Men and Women [abstract]. Arthritis Rheumatol. 2023; 75 (suppl 9). https://acrabstracts.org/abstract/plant-based-diet-quality-and-the-risk-of-gout-results-from-two-prospective-cohort-studies-of-us-men-and-women/. Accessed November 20, 2023.}