Science briefs: No insomnia, blood pressure link

No insomnia, blood pressure link

New research from St. Michael’s Hospital in Toronto has found that adults who suffer from insomnia are not at increased risk of developing high blood pressure.

Dr. Nicholas Vozoris, a respirologist there, said previous studies that suggested a link between insomnia and high blood pressure were often based on small numbers of people. He examined data from nearly 13,000 Americans who participated in the National Health and Nutrition Examination Survey, a series of studies designed to assess the health and nutritional status of adults and children in the United States. The survey combines interviews and physical examinations.

Participants were asked about their insomnia symptoms; their responses were correlated with whether they had doctor-diagnosed hypertension, were taking anti-hypertension drugs or had measured high blood pressure.

“After adjusting for many factors, including whether or not participants were receiving blood pressure pills or sleeping pills, there were generally no associations between insomnia and high blood pressure, even among people who were suffering from insomnia the most often,” Vozoris said.

His findings were published this month in the Journal of Clinical Psychiatry .

Magnetic compass guides monarchs

Each fall, millions of monarch butterflies use a sophisticated navigation system to transverse 2,000 miles from breeding sites across the Eastern United States to an overwintering habitat in specific groves of fir trees in central Mexico. Scientists at the University of Massachusetts Medical School and Worcester Polytechnic Institute have identified a new component of this complex system: They report in the Nature Communications journal that monarchs use a light-dependent, inclination magnetic compass to help them orient southward during migration.

Monarchs use a time-compensated sun compass in their antennae to help them on their migratory journey to overwintering sites. During the absence of daylight cues, such as under dense cloud cover, migrants have been, surprisingly, seen flying in the expected southerly direction. The researchers suspected monarchs also possessed a light-dependent magnetic compass.

Using flight simulators equipped with artificial magnetic fields, monarch flight behavior was examined under diffuse white light conditions. It was found that tethered monarchs in the simulators oriented themselves in a southerly direction. Also, that the butterflies used the inclination angle of Earth’s magnetic field to guide their movement.

A sweetener from ordinary straw

As a sweetener, erythritol has many advantages: It does not make you fat; it does not cause tooth decay; it has no effect on the blood sugar; and unlike other sweeteners, it does not have a laxative effect. It is about 70 to 80 percent as sweet as sugar and is widely used in Asia. Up until now, erythritol could only be produced with the help of special kinds of yeast in highly concentrated molasses. But at Austria’s Vienna University of Technology, a method has now been developed to produce the sweetener from ordinary straw with the help of a mold fungus.

“We knew that the mould fungus Trichoderma reesei is, in principle, capable of producing erythritol, but usually only in tiny quantities,” said research chemist Robert Mach. “By genetically modifying it, we managed to stimulate the production of an enzyme (that) enables the large-scale production of the sweetener.”