The liver plays an important role in the prevention of metabolic disorders, like Type 2 diabetes, Gaucher’s disease and hemochromatosis. As the largest organ and gland in the human body, the liver carries out over 500 tasks, including breaking down fats, regulating blood sugar levels and filtering out harmful compounds from the blood. However, the liver might struggle to function properly if the body produces too much fat, which can cause liver failure in extreme cases. Individuals who show risk factors relating to metabolic syndrome are often at risk of liver complications.
In a recent study published in Journal of Endocrinology, researchers from the University of Campinas (UNICAMP) in Sao Paulo State, Brazil showed that strength training led to the reduction of liver fat and risk of diabetes in obese mice. The researchers subjected the mice to 15 days of strength training in order to observe its effects on the mice without over-training them. After 15 days, they found a significant improvement in the mice’s blood sugar levels and liver fat content. They hope to use the results of the study to create treatments for diabetics in the future.
The link between NAFLD and Type 2 diabetes
Non-alcoholic fatty liver disease (NAFLD) is a condition marked by a build-up of extra fat in liver cells that is not caused by alcohol. When the body cannot properly transform glucose into energy, blood sugar levels increase, putting the individual at risk of Type 2 diabetes, a metabolic disorder that leaves the body vulnerable to other metabolic abnormalities like obesity and NAFLD.
An individual is at risk of NAFLD if more than five to 10 percent of their liver’s weight is fat. Fortunately, aerobic exercises, like running, cycling and swimming, can help prevent the onset of NAFLD. However, little is known about the possible effects of anaerobic exercises, like strength training, on individuals at risk of developing NAFLD. Hence, the researchers from Sao Paulo attempted to investigate how strength training might affect the livers and blood sugar levels of obese mice. Doing so might provide insight into how healthcare professionals can treat individuals with NAFLD and Type 2 diabetes.
To examine the effects of strength training, the researchers conducted a 15-day experiment on groups of mice with varying diets and exercise frequency. They placed group A under a standard diet with no exercise, group B on a high-fat diet with no exercise and group C on the same high-fat diet with strength training for two weeks. They found that the mice in group B became obese and diabetic, while the mice in group C experienced significant reductions in their blood sugar levels. Although group C was still obese, the researchers discovered that strength training reduced liver fat by 25–30 percent.
The effects of strength training on the liver
Anaerobic exercises, like strength training, are used by athletes and physical fitness enthusiasts to improve strength, speed and power. Unlike aerobic exercises that boost endurance, anaerobic exercises are primarily used to build muscle mass. A study published in Mayo Clinic Proceedings showed that individuals with moderate muscular strength had a 32 percent lower risk of developing Type 2 diabetes compared to individuals with low muscular strength. (Related: Strength training, more than walking and cycling, significantly reduces heart disease risk.)
Lead author Leandro Pereira de Moura confirms this, adding, “Everyone knows physical exercise helps control disease. Our research focuses on how and why this is so, on the mechanisms involved.” Hence, the researchers observed the effects of strength training on the liver to evaluate those mechanisms. They found that the mice produced less glucose than the obese, sedentary group. Additionally, strength training helped lower the risk of fat accumulation and inflammation in the liver.
Type 2 diabetes continues to affect millions of people around the world. In 2016, about 1.6 million deaths were caused by diabetes. By revealing the effects of anaerobic exercise on blood sugar levels and liver health, the study from Sao Paulo can encourage scientists and healthcare professionals to create better and more effective treatments for those suffering from various metabolic disorders.