Effects of a diet containing different sources of omega-3 fatty acids on kidney-related biomarkers in overweight and obese individuals: a randomized clinical trial

Abstract

Purpose: Recent research has suggested the beneficial effects of omega-3 fatty acids on kidney function; however, differences in these benefits have not been well-documented with respect to different omega-3 fatty acid sources. Hence, the purpose of this study is to compare the effects of plants, marine sources of omega-3 fatty acids and their combination on biomarkers of renal function in overweight and obese individuals. Design/methodology/approach: Ninety-nine overweight and obese women from a weight loss clinic received three weight-reducing diets with fish (300 g/week), walnuts (18 walnuts/week) or fish + walnuts (150 g fish + 9 walnuts/week) for 12 weeks. Serum biomarkers of renal function were measured at the beginning and the end of the intervention. Findings: After 12 weeks, a reduction in serum creatinine was statistically higher for both the fish + walnut (−0.16 ± 0.09 mg/dL, p = 0.001) and walnut (−0.15 ± 0.05 mg/dL, p = 0.001) diets compared with the fish diet (−0.05 ± 0.04 mg/dL). A significant decrease was seen in blood urea nitrogen (BUN) level in the fish + walnut group (−0.12 ± 0.05 mg/dL, p = 0.03) and walnut group (−0.10 ± 0.04 mg/dL, p = 0.03) compared to the fish group (−0.05 ± 0.03 mg/dL). The effect of serum creatinine and BUN in the fish + walnut diet group was relatively higher than in the walnut diet group. Also, a significant difference was observed regarding weight loss in the fish + walnut diet (−7.2 ± 0.9 kg, p = 0.03) compared to in the other groups. The change in other indices was not different among the three diets. Originality/value: This study found synergistic benefits of the plant and marine omega-3 fatty acids in reducing serum creatinine, BUN and weight compared with isolated marine omega-3s in overweight and obese women. © 2020, Emerald Publishing Limited.