The metabolic syndrome is associated with an increased risk of development and progression of chronic kidney disease. Renal inflammation is well known to play an important role in the initiation and progression of tubulointerstitial injury of the kidneys. Ginger, one of the most commonly used spices and medicinal plants, has been demonstrated to improve diet-induced metabolic abnormalities. However, the efficacy of ginger on the metabolic syndrome-associated kidney injury remains unknown. This study aimed to investigate the impact of ginger on fructose consumption-induced adverse effects in the kidneys.
The fructose control rats were treated with 10% fructose in drinking water over 5 weeks. The fructose consumption in ginger-treated rats was adjusted to match that of fructose control group. The ethanolic extract of ginger was co-administered (once daily by oral gavage). The indexes of lipid and glucose homeostasis were determined enzymatically, by ELISA and/or histologically. Gene expression was analyzed by Real-Time PCR.
In addition to improve hyperinsulinemia and hypertriglyceridemia, supplement with ginger extract (50 mg/kg) attenuated liquid fructose-induced kidney injury as characterized by focal cast formation, slough and dilation of tubular epithelial cells in the cortex of the kidneys in rats. Furthermore, ginger also diminished excessive renal interstitial collagen deposit. By Real-Time PCR, renal gene expression profiles revealed that ginger suppressed fructose-stimulated monocyte chemoattractant protein-1 and its receptor chemokine (C-C motif) receptor-2. In accord, overexpression of two important macrophage accumulation markers CD68 and F4/80 was downregulated. Moreover, overexpressed tumor necrosis factor-alpha, interleukin-6, transforming growth factor-beta1 and plasminogen activator inhibitor (PAI)-1 were downregulated. Ginger treatment also restored the downregulated ratio of urokinase-type plasminogen activator to PAI-1.
The present results suggest that ginger supplement diminishes fructose-induced kidney injury through suppression of renal overexpression of macrophage-associated proinflammatory cytokines in rats. Our findings provide evidence supporting the protective effect of ginger on the metabolic syndrome-associated kidney injury.
Alex’s Notes: Ginger is one of the most commonly used spices in the culinary world, and one of the most well researched medicinal plants. It has been demonstrated that ginger has numerous pharmacological effects, and ginger supplementation improves fructose-induced non-alcoholic fatty liver disease (NAFLD) and insulin sensitivity. These effects are nothing but beneficial in today’s Western diet rich in high-fructose corn syrup products. Moreover, the Western diet is strongly associated with the metabolic syndrome, which is an independent risk factor for developing chronic kidney disease. Preliminary evidence also demonstrates that high levels of fructose consumption can damage kidneys in rodents. Given ginger’s protective effects on the liver and other body organs, the study at hand examined its impact on kidney damage from chronic fructose consumption in rats.
The rodents were divided into four groups: a water control, a fructose control, a fructose with 20mg/kg ginger, or a fructose with 50mg/kg ginger. As expected, in the fructose control plasma concentrations of insulin, total cholesterol, and triglycerides were elevated, and the addition of 20mg/kg ginger didn’t help. However, supplementing with 50mg/kg ginger significantly reduced blood glucose, insulin, and triglyceride concentrations, but left cholesterol unchanged compared to the fructose control group. More importantly, the fructose feeding induced a pronounced increase in tubular damage of the kidneys, which the 50mg/kg ginger supplementation alleviated. It appeared that the protective effects of ginger were associated with suppression of kidney inflammation.
The 50mg/kg dosage used in the study was a 9.6% extract equal to 520mg/kg of dried ginger. The human equivalent dose would thus be about 84mg/kg of dried ginger, or 6.3g for a 165lb adult. Whether or not it’s worth it is a decision for you and your wallet, but in my opinion you would probably get better results by eliminating the soda and other high-fructose processed foods in your diet. Treat the cause, not the symptom.