Study shows healthy plant-based diets lower gout risk, unhealthy diets raise it

By Dr. Liji Thomas, MDReviewed by Benedette Cuffari, M.Sc.May 26 2024

A recent study published in JAMA explores the potential benefits of a plant-based diet on gout risk.

Study: Differences in plant-based diets affect gout risk. Image Credit: Ju Jae-Young / Shutterstock.com

How does diet affect gout?

Gout is an inflammatory condition affecting the joints that occurs in about 4% of Americans. This condition is often painful and can be disabling, in addition to increasing the risk of cardiometabolic disease, mortality, and poor mental health.

Certain food products, including alcohol, red meat, fish, and sugary drinks, have been shown to increase the risk of gout. Conversely, skim dairy products, coffee, certain vegetables, and ascorbic acid can reduce the risk of gout.

Healthy diet patterns, such as the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diet, have also been shown to reduce the risk of gout. However, less is known about the effects of plant-based diets on the incidence of gout.

About the study

The current study used data from Americans enrolled in the Health Professionals Follow-Up Study, which was conducted between 1986 and 2012, and the Nurses’ Health Study, which was conducted from 1984 to 2010. All study participants were gout-free at the beginning of the study.

The study aimed to measure mean exposure to an overall plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI). These indices were calculated based on 18 food groups determined using a food frequency questionnaire.

What did the study show?

The study included nearly 123,000 participants, with a mean age of 54 and 50.9 for men and women, respectively. Over the period of nearly 2.8 million person-years, new-onset gout was reported in 2,700 individuals.

The overall PDI did not correlate with gout incidence in either men or women. However, when hPDI was compared with uPDI, hPDI had a negative association with gout, whereas uPDI had a positive association.

The risk of gout increased by 17% in the hPDI cohort from the highest to the least quintile, while it was nearly 20% lower from the highest to the least quintile in the uPDI cohort.

The reduction with increased hPDI was even higher among women. When only men were evaluated, there was no significant association.

The risk in the uPDI cohort was especially raised in women, among whom gout risk increased by almost 33% in the uPDI quintile with the highest intake of unhealthy plant-based foods. This risk was not significant among men.

Whole grains reduced the risk of gout by 7% per serving, tea and coffee by 5% per serving, and dairy products by 15% per serving. Conversely, fruit juice and sugary drinks increased the risk of gout by 6%, whereas vegetable oils increased the risk of gout by 16% per serving. The inverse association between whole grains and gout risk was reported in the current study for the first time.

Healthy foods without an associated risk of gout included fruits, vegetables, nuts, and legumes. Unhealthy plant-based foods without increased gout risk included sweets, desserts, potatoes, and refined grains.

Animal fats and fish were associated with an increased risk of gout. However, the consumption of eggs, overall meat, and other animal products was not associated with an increased risk of gout.

Fish is purine-rich, which can increase serum uric acid levels and, as a result, increase an individual’s vulnerability to gout. The reduction of gout risk with sweets and desserts and the lack of an association with refined grains requires further exploration to understand the mechanisms responsible for this association.

Conclusions

The study findings provide additional validity to current dietary guidelines that recommend an increased consumption of healthy plant foods and a lower intake of unhealthy plant-based foods to reduce the risk of gout.

The benefits of including eggs and dairy in a vegetarian diet have been shown to reduce serum uric levels and, as a result, the risk of gout. These dietary patterns are more likely to be followed over the long term as compared to more rigorous or exclusive diets.

The hPDI shares features with the DASH and Mediterranean diets, such as an emphasis on consuming fruits, vegetables, whole grains, nuts, and legumes. This adds to the growing literature of candidate dietary patterns for gout prevention.”