One of the most common chronic liver diseases worldwide is Nonalcoholic fatty liver disease (NAFLD). Obese, sedentary people and patients with type II diabetes are mainly subject to NAFLD which includes a variety of liver disorders from simple steatosis to hepatic fibrosis, and cirrhosis. This disease is usually associated with metabolic disorders such as obesity, insulin resistance, hypertension, dyslipidemia, and impaired fat metabolism. Moreover, it can increase mortality risk due to the associated cardiovascular disease. (1)
The cause of NAFLD is still unknown. The two-hit hypothesis, first expressed by James and Day, is the accepted hypothesis that explains the pathogenicity of the NAFLD as follows:
Insulin resistance (the first hit) causes stimulation of the synthesis of liver fatty acids, accumulation of fat in the liver, and steatosis. As a result, the liver is more susceptible to oxidative stress from different sources (the second hit).
There is currently no definitive treatment for NAFLD. So, we urgently need to find new therapeutic approaches to replace or help with existing fatty liver treatments. (2) A combination of modified diet and exercise for treatment have been suggested by researchers. (1)
Previous studies have pointed out that diets containing antioxidants and anti-inflammatory agents in some medicinal plants may be beneficial in the treating of NAFLD; (2) one of these medicinal plants is ginger.
Ginger is the root of Zingiber officinale and is one of the most commonly used spices in many countries. It contains active ingredients such as gingerol, shogaol, zingerone, β-bisabolene, (1) and more than 40 antioxidant compounds. (2) Ginger has been approved as a food supplement by the Food and Drug Administration.
As shown in previous studies, ginger and its active compounds have anti-diabetes, anti-cancer, and anti-inflammatory properties. They have shown that ginger extract can exhibit antioxidant activity and reduce the levels of pro-inflammatory biomarkers. Moreover, recent studies on patients with Type II diabetes and hyperlipidemia have shown that ginger can reduce insulin resistance and serum triglyceride concentration. (1)
Preclinical studies done in the past decade have shown that ginger has hepatoprotective effects and can protect against diverse xenobiotic compounds like alcohol, acetaminophen, fungicides, tetracycline, heavy metals, and organophosphorus compounds.
Mechanistic studies have shown that it protects the liver and modulates the levels of the detoxifying enzymes by free radical scavenging, antioxidant and cytoprotective properties. (3)
Accordingly, this hypothesis was proposed that ginger supplementation can be introduced as a new therapeutic strategy for NAFLD because it improves the body’s antioxidant activity and reduces the levels of inflammation and insulin resistance. A randomized, double-blind study was designed to examine this hypothesis and the effectiveness of ginger supplementation in patients with NAFLD.
In this randomized, double-blind, placebo-controlled clinical trial, 44 patients with NAFLD were asked to take either two grams per day of a ginger supplement or the identical placebo, for 12 weeks. The patients of both groups were advised to follow a modified diet and physical activity program. The metabolic parameters and indicators of liver damage were measured at the study baseline and after the 12-week intervention. Based on the results, ginger supplementation resulted in a significant reduction in alanine aminotransferase, γ-glutamyl transferase, inflammatory cytokines, as well as the insulin resistance index and hepatic steatosis grade in comparison to the placebo. The researchers did not find any significant effect of taking ginger supplements on hepatic fibrosis and aspartate aminotransferase. They found that twelve weeks of two grams of ginger supplementation showed beneficial effects on some NAFLD characteristics. They finally recommended further studies to assess the long-term supplementation effects.
Insulin resistance is one of the major risk factors in the pathogenesis of NAFLD. This study has shown that ginger supplementation reduces insulin resistance, which is in line with previous studies. (1)
Another study, published in the journal of Clinical and Experimental Gastroenterology in 2020, was carried out in order to determine the effect of ginger powder supplement on lipid profiles, insulin resistance, liver enzymes, inflammatory cytokines, and antioxidant status in patients with NAFLD.
In this randomized clinical trial, the researchers divided 46 people with NAFLD into two groups. One group was subjected to the ginger, and the other to placebo capsules over 12 weeks (3 capsules daily, each containing 500 mg of ginger or wheat flour). They took one capsule an hour after breakfast, the second one an hour after lunch, and the third an hour after dinner. All patients received a diet with balanced energy and physical activity during the intervention period. Liver ultrasonography, anthropometric indices, and biochemical parameters were measured before and after the intervention.
Based on the results, no significant difference was found between the two groups in the baseline variables at the beginning of the study. At the end of the study, serum levels of alanine aminotransferase (ALT), total cholesterol, low-density lipoprotein (LDL-C), fasting blood glucose, insulin resistance index (HOMA), and parameters associated with cardiovascular disease )C-reactive protein (hs-CRP), and fetuin-A( in the group receiving a ginger supplement were significantly decreased compared to the placebo group. However, there was no significant difference between the two groups in body weight, fasting insulin, HDL-C, triglyceride, adiponectin, alpha-tumor necrosis factor (TNF-α), total antioxidant capacity (TAC), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), fatty liver index (FLI), fatty liver grade, and blood pressure.
The researchers concluded that the ginger supplement might be used as a complementary therapy along with existing therapies to reduce insulin resistance, liver enzymes, and inflammation in patients with non-alcoholic fatty liver.
1- Rahimlou, M., Yari, Z., Hekmatdoost, A., Alavian, S.M., & Keshavarz, S.A. (2016). Ginger Supplementation in Nonalcoholic Fatty Liver Disease: A Randomized, Double-Blind, Placebo-Controlled Pilot Study. Hepatitis Monthly, 16(1), e34897. Retrieved from http://hepatmon.com/articles/15603.html
2- Rafie, R., Hosseini, S.A., Hajiani, E., Malehi, A.S., & Mard, S.A. (2020). Effect of Ginger Powder Supplementation in Patients with Non-Alcoholic Fatty Liver Disease: A Randomized Clinical Trial. Clinical and Experimental Gastroenterology, 13, 35–45. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6986243/
3- Haniadka, R., Saxena, A., Shivashankara, A.R., Fayad, R., Palatty, P.L., Nazreth, N., … Baliga, M.S. (2013). Ginger Protects the Liver against the Toxic Effects of Xenobiotic Compounds: Preclinical Observations. Journal of Nutrition & Food Sciences, 3(5), 226. Retrieved from https://www.longdom.org/open-access/ginger-protects-the-liver-against-the-toxic-effects-of-xenobiotic-compounds-preclinical-observations-2155-9600.1000226.pdf
