The popular herbal supplement black cohosh does not relieve hot flashes among women going through menopause, according to a study by researchers from Group Health Cooperative, a Seattle-based health care system.
Published in the December 19 issue of the Annals of Internal Medicine, this study is the first of its kind to compare various forms of black cohosh to a placebo and to hormone therapy (estrogen with or without progestin).
"Black cohosh used alone or as part of a multibotanical supplement shows little potential as an important therapy for relief of hot flashes," the researchers concluded. The herbal interventions were no better than placebo. Hormone therapy, on the other hand, significantly reduced the frequency of hot flashes.
"We were disappointed by the findings because many women want an alternative to hormone therapy, and many have assumed that black cohosh is a safe, effective choice," said Katherine M. Newton, PhD, associate director of Group Health Center for Health Studies and the principal investigator of the study. "While hormone therapy is still the most effective treatment for hot flashes, recent studies have shown that it poses serious risks."
Newton estimates that 80 percent of women experience hot flashes around the time of menopause, which typically happens between ages 45 and 55. The average age of menopause is 51.
To conduct the study, the researchers randomly assigned 351 peri-menopausal or post-menopausal women, aged 45 to 55, to one of five therapies:
1) black cohosh (160 mg daily)
2) multibotanical supplement, including black cohosh (200 mg daily), alfalfa, boron, chaste tree, dong quai, false unicorn, licorice, oats, pomegranate, and Siberian ginseng
3) multibotanical supplement plus diet counseling to increase consumption of soy
4) menopausal hormone therapy (estrogen with or without progestin)
The study was double-blinded, meaning that the study participants and the staff did not know which treatment was assigned to any given woman. Evaluating the women at three, six, and 12 months, the researchers found no significant difference between the numbers of daily hot flashes in any of the herbal supplement groups when compared to the placebo group. Specifically, women taking the herbal treatments reduced their hot flashes by about one half an episode per day when compared to women taking the placebo. The women taking hormone therapy reduced their hot flashes by about bout four episodes per day when compared to placebo.
"Prior to our study, the trials of black cohosh were small and of short duration," explains Susan Reed, MD, MPH, co-investigator and professor of obstetrics and gynecology at the University of Washington. "Our study was the largest and longest to date. Plus, we had good controls with both the placebo and hormone therapy arms, allowing us to definitively show differences between the groups taking herbs and the placebo group."
With no strong evidence that herbal alternatives work for hot flashes, Newton suggests several behavioral changes women can make. These include dressing in layers, sleeping in a cooler room, keeping ice water and a fan nearby, and avoiding possible triggers such as very hot liquids and alcohol.
Newton also notes that hot flashes decreased during the 12-month course of participation in all the study groups, including the placebo group. "We call this the ‘tincture of time'—that is, over time, hot flashes nearly always go away on their own," Newton said.
Joan DeClaire | EurekAlert!
Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center
Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy