(NaturalNews) Cholesterol levels are not just affected by what you eat, but also by a hunger-regulating hormone released by the brain, according to a study conducted by researchers from the University of Cincinnati and published in the journal Nature Neruoscience.
"We have long thought that cholesterol is exclusively regulated through dietary absorption or synthesis and secretion by the liver," lead researcher Matthias Tschoep said. "Our study shows for the first time that cholesterol is also under direct 'remote control' by specific neurocircuitry in the central nervous system."
The researchers found that the hormone ghrelin, which is known to play a role in the regulation of food intake and energy use, also increased the blood cholesterol levels of laboratory mice. The higher blood levels came as a direct result of ghrelin's signaling the liver to store less of the substance.
High blood cholesterol levels are associated with a higher risk of atherosclerosis, in which plaques build up in arteries and raise the risk of heart attack and stroke.
Ghrelin is known to act in part by blocking a certain receptor in the brain. When researchers blocked this receptor by other means, they found that blood cholesterol levels increased once more.
"Inhibiting the brain's melanocortin system by pharmacological, genetic or endocrine mechanisms increased circulating HDL cholesterol by reducing its uptake by the liver independent of food intake or body weight," they wrote.
The health implications of the finding remain unknown, in part because HDL cholesterol (also known as "good" cholesterol), is actually believed to be beneficial. In contrast, LDL ("bad") cholesterol is believed to increase the risk of heart disease.
Cholesterol is a critical precursor to various vitamins, hormones and digestive acids in the body.
"This could potentially open up new forms of treatment to control cholesterol levels, which would be great news for people with heart and circulation problems," said Fotini Rozakeas of the British Heart Foundation. "In the meantime, people should reduce the amount of saturated fat in their diet [and] take part in regular physical activity."