Diet quality can significantly affect an individual’s risk of developing rheumatoid arthritis (RA), according to results of 2 studies presented at the 2015 annual meeting of the American College of Rheumatology.
Lead researcher Bing Lu, MD, DrPH, assistant professor of medicine at Brigham and Women’s Hospital and Harvard Medical Center, and colleagues conducted an initial study that revealed a Western diet—high in red meat, high-fat dairy, and sweets—can increase risk of RA when compared to a prudent diet consisting of mostly fruit, vegetables, whole grains, poultry, and fish.
“Overall dietary pattern analysis examines the cumulative effects of multiple nutrients and foods, and may be more predictive of disease risk than individual foods or nutrients,” Dr Lu stated in a press release.
“The single-nutrient approach may be inadequate for taking into account complicated interactions among nutrients, and high levels of intercorrelation makes it difficult to examine their separate effects. Therefore, we proposed a prospective study examining the overall effect of dietary patterns to furnish novel information about diet and etiology of RA.”
Dr Lu’s team followed 93,859 women without RA and between the ages of 25 and 42 from the Nurses’ Health Study II. The women completed dietary questionnaires every 4 years between 1991 and 2011. Researchers analyzed dietary patterns from the questionnaires, which revealed the divide between Western and prudent diets.
By the end of the study, 347 women had developed RA at an average age of 49 years. The researchers found that women on a prudent diet had decreased risk of developing RA after considering age, smoking status, body mass index (BMI), calories consumed per day, alcohol consumption, and level of physical activity.
Dr Lu noted that BMI disrupted these results, which suggests that BMI may have an additional effect on RA risk. “Therefore, adherence to a healthy diet may be a way to prevent this debilitating disease, especially for high-risk populations,” said Dr Lu.
The researchers conducted a second study to determine how the US Office of Disease Prevention and Health Promotion Dietary Guidelines for Americans, which provide advice about consuming fewer calories, affect RA risk. They used data from the previous study and found that participants who adhered to the guidelines had a 33% reduced risk of developing RA.
Of the 347 individuals who developed RA, 215 had seropositive RA and 132 had seronegative RA. The researchers noted that the association between developing RA and following the dietary guidelines was stronger among individuals with seronegative RA than those with seropositive.
“As we found with the first study, it is clear that a healthy diet may prevent RA development, and our team is interested in conducting further studies to look at why diet is associated with this risk,” Dr Lu concluded.