Melatonin, a hormone known for helping to regulate the body’s internal clock, may help lower high blood pressure, Dutch and U.S. researchers reported Monday.
Supplements of the hormone, often used to help battle jet lag, reduced blood pressure in a small group of men who took them regularly, the researchers said.
“This finding might open the door for a new approach for treating hypertension,” said Frank Scheer, a neuroscientist at Brigham and Women’s Hospital and Harvard Medical School in Boston.
“It has been reported that people with high blood pressure often have suppressed nighttime melatonin levels,” Scheer added in a statement. “We have recently found that people with high blood pressure have actual anatomical disturbances of their biological clocks.”
Scheer’s team, working with researchers at the Netherlands Institute for Brain Research in Amsterdam, gave melatonin supplements or placebos to 16 men with untreated high blood pressure an hour before they went to bed.
Nightly use effective
The men who got nightly melatonin supplements for three weeks lowered their nighttime systolic blood pressure -- the top number -- by about 6 millimeters of mercury on average and their diastolic reading -- the bottom number -- by 4 millimeters of mercury.
There was no change from taking a single dose of melatonin, the researchers report in the February issue of Hypertension, a journal published by the American Heart Association.
High blood pressure is common, affecting 50 million Americans. It is a leading cause of heart attack, stroke and heart failure.
Many different drugs, from diuretics to medications that relax the arteries, are used to treat it. But they have side effects ranging from a frequent need to urinate to impotence.
Melatonin could offer a gentler approach, Scheer said. As a side benefit, he said the men reported sleeping better when they took melatonin.
It could be that sleeping better helps improve blood pressure, Scheer, said, although he stressed much more study is needed. He said no one with high blood pressure should start taking melatonin on his or her own.