Mice given the botanical supplement yerba mate showed significantly less weight gain than controls over a 16-week period of consuming a high-fat diet (HFD), found the researchers from KyungPook National University (Daegu) and Pukyong National University (Busan), Republic Of Korea.
Yerba mate is a flowering tree whose leaves are consumed as a tea. The leaves are known to contain numerous phytonutrients including chlorogenic and caffeic acids, quercetin, rutin, kaempferol and various saponins.
The supplemented mice displayed increased energy expenditure and expression of fat-burning (thermogenic) genes in fatty tissue (known as white adipose tissue (WAT)). Yerba mate also reduced levels of blood lipid parameters (free fatty acids, triglycerides and total cholesterol).
Additionally, yerba mate had positive effects on plasma leptin levels, insulin resistance, certain liver enzymes associated with hepatic injury, and liver fat accumulation in the mice.
“This study showed that supplementation of HFD with yerba mate (∼400 milligrams/kilogram (mg/kg) body weight) for 16 weeks significantly decreased final body weight and body weight gain compared to HFD control mice,“ wrote lead author Professor Myung-Sook Choi from Kyungpook National University.
The study also “Demonstrated that long-term supplementation of dietary yerba mate increased energy expenditure and upregulated mRNA expression of thermogenic genes in WAT,” she added.
Significance
The scientists suggest that yerba mate might have applications not only in controlling obesity, but also in prevention of type-2 diabetes (through reduced insulin resistance); and non-alcoholic fatty liver disease (NAFLD), due to its effect on de novo lipogenesis (the process of fat accumulation) in the liver.
“These findings support previous reports regarding the anti-obesity effect of yerba mate and suggest that yerba mate may represent a useful natural candidate for the control of obesity and obesity-related insulin resistance, dyslipidaemia, and hepatic steatosis,” proposed author Myung-Sook Choi,
Safety
A previous investigation in rats and rabbits showed no adverse effects of yerba mate supplementation for 90 days at 2g/kg, five times the dosage in this mouse study.
There is limited evidence to suggest that short-term supplementation in humans may improve markers of oxidative stress and low-density lipoprotein (LDL).
However, observational studies in humans have identified a possible increased risk of lung and upper digestive tract cancers associated with frequent consumption of yerba mate tea – a popular drink in South American countries.
Additional studies are therefore needed to determine longer-term safety and tolerability of yerba mate, suggest the researchers.
Source: Journal of Medicinal Food
Published online ahead of print, doi: 10.1089/jmf.2017.3995
“Long-Term Dietary Supplementation with Yerba Mate Ameliorates Diet-Induced Obesity and Metabolic Disorders in Mice by Regulating Energy Expenditure and Lipid Metabolism”
Authors: Myung-Sook Choi, Hyo Jin Park, Sang Ryong Kim, Do Yeon Kim, and Un Ju Jung