Japan: Vegetable and Fruit Intake and Mortality in CKD Patients

Everyday consumption of vegetables and fruits may reduce all-cause mortality in patients with CKD (chronic kidney disease), and non-CKD patients, research published in the Journal of Renal Nutrition has claimed.

The Japanese hospital-based study showed that a lower fruit and vegetable intake frequency is notably associated with a higher death risk regardless of CKD status.

Patients with worsening chronic kidney disease are generally discouraged from consuming high amounts of fruits and vegetables, given the potential hyperkalemia risk. However, a lower fruit and vegetable intake is linked with higher mortality in the general population; in a Japanese hospital-based prospective cohort study comprising CKD and non-CKD participants, Minako Wakasugi and colleagues from Japan examined whether vegetable and fruit intake frequency is linked with mortality and whether CKD presence modifies this association.

Study Details

The study included 2,006 patients who visited the outpatient department of a general hospital between 2008 and 2016 (mean age of 69 years). Among these participants, 7% and 45% were hemodialysis and non-dialysis-dependent CKD patients. The vegetable and fruit intake frequency was found out by a self-report questionnaire using an ordinal scale: "sometimes," "never or rarely," and "every day".

Findings

• Fruit and vegetable intake frequency decreased with worsening CKD stage.
• Baseline serum potassium levels stratified by CKD stage were comparable across the three fruit and vegetable intake frequency groups.
• 561 participants died (47.1/1,000 person-years) during a median follow-up of 5.7 years.
• Adjusted hazard ratios relative to the "everyday" group were 1.25 and 1.60 for the "sometimes" and "never or rarely" groups, respectively, after adjustments for comorbidities, demographic factors, and CKD status.
• A similar, albeit non-significant, dose-dependent relationship was seen between fruit and vegetable intake frequency and all-cause mortality irrespective of CKD status when stratified, with no effect modification by CKD status.

"Participants who sometimes and never/rarely consumed fruits and vegetables had an increased mortality risk compared with participants who consumed vegetables and fruits every day after adjustment for comorbidities, demographic factors, and CKD status," the research team wrote.

"This association was similarly observed irrespective of CKD status, with no effect modification by CKD presence or absence, indicating that everyday consumption of fruits and vegetables may reduce all-cause mortality in CKD as well as non-CKD patients," they conclude.

Reference

Wakasugi M, Yokoseki A, Wada M, Momotsu T, Sato K, Kawashima H, Nakamura K, Onodera O, Narita I, Vegetable and fruit intake frequency and mortality in patients with and without CKD: A hospital-based cohort study, Journal of Renal Nutrition (2023), doi: https://doi.org/10.1053/j.jrn.2023.01.011.