A team led by an Indian researcher claim to have uncovered how niacin (vitamin B3) helps in maintaining good cholesterol levels, thus reducing the risk of developing heart disease.
Niacin can increase plasma HDL levels, however, the mechanism of how it works has been mysterious. Some researchers also believed that niacin does not actually increase HDL production.
The work also identifies a new drug target, as no other drug in currently known to raise HDL by inhibiting the surface expression of the beta chain of ATP synthase.
The new study has found that a component of ATP synthase (the protein that makes ATP) is present on the surface of liver cells, and this subunit known as the 'beta chain' can take up HDL.
The team led by researcher Moti Kashyap found that this beta chain is the basis of niacin's effect.
They added niacin to samples of human liver cells and found that treatment reduced the presence of Beta chain on the cell surface by ~27pct, and as a result HDL uptake was reduced by ~35pct.
This shows that niacin hinders the liver from removing HDL from the blood, thus maintaining high plasma HDL levels.
However, it does not affect another major pathway known as "Reverse Cholesterol Transport."
Therefore, it maintains HDL levels while still allowing the removal of other cholesterol types, explaining why niacin is especially beneficial.