Herbs vs drugs Abdominal breathing exercises can halve the number of attacks, according to researchers investigating treatments for a condition that affects seven out of 10 women during and after the menopause.
Now, a much larger clinical trial of breathing exercises is underway as researchers look for new treatments for the condition.
Although hormone replacement therapy has been considered the most effective treatment for hot flushes, it is not suitable for all women, and reports linking it to increased risks for breast cancer, heart disease, and stroke, have led to increasing numbers women looking for alternatives, fuelling a search for new remedies.
Hot flushes, a sensation of intense heat, sweating, and flushing, which last for five to 10 minutes, are the main reason women seek medical help for the menopause, ahead of night sweats and mood and sleep disturbances.
But despite the huge number of sufferers, and the distress it can bring about, the exact cause of hot flushes is not known, although there are a large number of theories.
One suggestion is that the drop in oestrogen levels, that occurs around the menopause, affects the part of the brain involved in body temperature control. Another theory is that changes in other brain chemicals, including serotonin, are implicated.
Whatever the cause, the effects can include a rise in skin temperature in the cheeks, forehead, upper arms, chest, abdomen, back, calves, thighs and fingers, with increased blood flow in the hands, calves, and forearms. The increase in heat causes blood vessels just under the skin surface to dilate - get bigger - resulting in the classic florid cheek look associated with hot flushes.
For the 70 to 75 per cent of women who have menopausal hot flushes, some of whom experience several attacks a week for four or more years, there is a bewildering range of over-the-counter and prescription treatments available. Many have been found to be effective, but large numbers have not, and in some cases the placebo or dummy treatment has been shown to be as effective as the therapy on trial.
Dr Elena Umland, of Thomas Jefferson University, Philadelphia, who has carried out a new review of treatments, says that evidence for the effectiveness of some herbal remedies that many women take is inconsistent and inconclusive, and that the way they work is not known.
"The physical and financial burden imposed by menopause associated hot flushes is immense," she says. "Optimum management includes lifestyle changes in all women and HRT in women with moderate-to severe symptoms. Less effective herbal remedies or non-hormonal therapies may be appropriate in certain women, such as those with mild symptoms or those who cannot or will not take HRT."
What works, what might, and what doesn't
Hormone therapy
Trials show it is effective. According to a report from Thomas Jefferson University, an analysis of 24 trials, which included 3,329 women, showed a 75.3 per cent drop in the frequency of hot flushes experienced each week, and an 87 per cent reduction in severity of symptoms.
Deep breathing
In new research at Indiana University, doctors are recruiting around 200 women for the biggest trial yet of slow deep breathing. It follows a number of small studies which have shown that it can be highly effective. Results from a study at Wayne State University in America, show that paced respiration - slow, deep, abdominal breathing - reduced hot flush frequency by around 50 per cent. Other exercises could work too. A study by the American College of Sports Medicine showed that strength training helped to reduce hot flushes by up to 50 per cent.
See the guide to DIY deep breathing exercises at the bottom of this page.
Lifestyle changes
Can be effective. "Lifestyle changes should be implemented by all women with menopause-associated hot flushes, Interventions that help regulate core body temperature include wearing lightweight cotton clothing, dressing in layers, using fans or air conditioning, consuming cool or cold foods and drinks, and avoiding hot foods and drinks," say Thomas Jefferson University researchers.
Anti-depressants
Low doses of some antidepressants may reduce hot flushes, according to research at the US Mayo Clinic. Selective serotonin re-uptake inhibitors - SSRIs - are among those that have positive effects. "Many doctors now consider these anti-depressants the treatment of choice if you have troublesome hot flashes and can't - or choose not to - take hormone therapy. But they aren't as effective as hormone therapy for severe hot flashes and may cause unwanted side effects, such as nausea, dizziness, weight gain or sexual dysfunction."
Gabapentin
An anti-convulsant, used for treating seizures and pain associated with shingles, has been shown to reduce symptoms, according to a Wayne State University School of Medicine report, but it is not known how. A study involving 59 women found a reduction of hot flush frequency of 45 per cent compared to 29 per cent for placebo treatment.
Clonidine
A pill or patch used to treat high blood pressure, may provide some relief, although there may be side effects including dizziness, drowsiness and dry mouth. According to a Wayne State University School of Medicine study, two small trials found that the pill reduced hot flush frequency by 46 per cent and the patch by 80 per cent
Acupuncture
Mixed findings from research. In one study, women who were having moderate to severe hot flushes, who were given acupuncture did benefit. "Individually-tailored acupuncture treatment was associated with significantly greater decrease in the severity, but not the frequency, of hot flushes, when compared to placebo acupuncture," say the researchers from Stanford University in America.
Yoga
A study at the University of California showed that eight weekly 90-minute sessions led to an average drop in hot flushers each week of 30.8 per cent. The researchers say bigger trials are now needed.
Soy
Some trials show it is helpful, while others have found no effect. Its use is based on the idea that soy contains compounds called isoflavones which have some small oestrogen-like effect. A study at the University of Minnesota concluded, "Consumption of 30 mg/day of soy isoflavones reduces hot flashes by up to 50 per cent."
Vitamin E
An antioxidant, it has been extensively used for menopausal symptoms. But a Mayo Clinic report says, "Studies using vitamin E in doses up to 400 international units a day have found little benefit in relieving hot flashes. Vitamin E is no longer recommended for treating hot flashes."
Black cohosh
It's widely used, but some research questions its effectiveness. In a year-long clinical trial funded by the US National Institutes of Health, it was found to be no better than a placebo for relieving hot flushes. The women given black cohosh-containing supplements had the same number of daily hot flushes as women given a placebo. "While its safety record has been good, there's no longer much reason to believe that it's effective for menopausal symptom relief," concludes a Mayo Clinic report.
Red Clover
"Although several small studies of red clover for menopausal symptoms had mixed results, a large study found that red clover had no beneficial effects on menopausal symptoms," says a report from the US National Institutes of Health.
Other herbal remedies
A wide range of herbs are used for hot flushes, but researchers say evidence of effectiveness is lacking for most. Clinical trials have not supported the use of sage, ginseng, liquorice, sarsaparilla, dong quai, ginkgo biloba and valerian root for hot flushes, according to a report in the medical journal Geriatric Nursing.
DIY breathing exercise for hot flushes*
Deep breathing, or relaxation breathing or paced respiration, involve breathing in deeply and exhaling at an even pace. Do this for several minutes while in a comfortable position.
You should slowly breathe in through your nose. With a hand on your stomach right below your ribs, you should first feel your stomach push your hand out, and then your chest should fill. Slowly exhale through your mouth, first letting your lungs empty and then feeling your stomach sink back. You can do this almost anywhere and several times during the day, whenever you feel stressed. You can also try this if you feel a hot flush beginning or if you need to relax before falling asleep
*Source: US Government's National Institute of Aging