The effect of low-level laser therapy on liver enzymes in people with nonalcoholic fatty liver disease Original paper

Low-level laser therapy, also known as photobiomodulation, is a method that applies certain wavelengths of light (typically red or infrared) to the body with the intention of inducing a beneficial effect on health. Some evidence suggests that low-level laser therapy may improve markers of metabolic health, including blood lipids and inflammatory markers. What is the effect of low-level laser therapy on markers of liver function in people with nonalcoholic fatty liver disease (NAFLD)?

This 12-week trial tested the effect of low-level laser therapy (LLLT) on markers of liver function among 60 people (ages 65 to 75) with NAFLD. The LLLT device used a 660 nm wavelength with an energy density of 127.8 J/cm². The light was applied to the abdomens and waists of the participants for 30 minutes per session, twice per week.

All participants were assigned to follow a calorie-restricted Mediterranean diet rich in extra virgin olive oil, whole grains, eggs, fruits and vegetables, legumes, and nuts, with some poultry and fish and limited red meat and dairy. The primary outcomes were the liver enzymes aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP). The secondary outcomes were lipid profile parameters (LDL-C, HDL-C, total cholesterol, and triglycerides), BMI, and waist circumference.

All participants experienced a decrease in AST, ALT, ALP, BMI, waist circumference, LDL-C, total cholesterol, and triglycerides and an increase in HDL-C. Each of these changes occurred to a greater extent in the LLLT group.