Researchers at Massachusetts Institute of Technology (MIT) have found that SIRT1 boosts the activity of a protein called LXR (liver X receptor), so that cholesterol is expelled from cells such as macrophages and out of the body by HDL(high density lipoprotein or "good cholesterol").
When the levels of SIRT1 were low, the LXR activity was reduced, resulting in the build-up of cholesterol in macrophages, showed the study.
The researchers believe that their findings may lead to the development of drugs for lowering the risk of diseases associated with high cholesterol, such as atherosclerosis (clogged arteries) and Alzheimer's disease.
"SIRT1 is an important mediator of cholesterol efflux, and as such it's predicted to play a role in the development of age-associated diseases where cholesterol is a contributing factor," said Leonard Guarente, MIT professor of biology and senior author of the study reported in the journal Molecular Cell.
He said that drugs that enhance the effects of SIRT1 could lower the risk of cholesterol-related diseases.
According to Guarente, potential drugs could be based on polyphenols, which are found in red wine and have been shown to enhance SIRT1. However, the quantities naturally found in red wine are not large enough to have a significant impact on cholesterol levels.
Previous studies had shown that high levels of SIRT1 could be achieved with extreme calorie restriction, but most people do not find this suggestion appealing.
"If you had a drug that could increase expression of SIRT1, that could replicate the effects of calorie restriction. This is not going to replace the need for a healthy lifestyle, but it's a supplement that could potentially make you healthier," Guarente said