Managing menopause: how to curb hot flashes, bone loss, and other symptoms

Nutrition Action Healthletter, July-August, 2004 by David Schardt

In 1900, a woman born in the U.S. could expect to live to age 48. Today, she's more likely to reach age 80.

"Women are living one third of their lives after menopause," says Susan Hendrix of the Wayne State University School of Medicine in Detroit. So getting through the hot flashes and dealing with the increased risk of heart disease and bone and memory loss isn't just academic.

More than a million American women enter menopause each year in the prime of their lives. And research on preventing or curbing its symptoms is no longer considered an oddity.

"I started studying hot flashes more than 20 years ago, and when I told people what I was working on, they would giggle," remembers Robert Freedman of Wayne State University, the dean of hot flash research in the U.S. "They don't do that any more."

Here's some of what menopause researchers have learned over the past several decades.

Hot Flashes

Hot flashes are the most common symptom women experience during menopause. Seventy-five percent of the 2,500 participants in the Massachusetts Women's Health Study, for example, reported having had hot flashes during menopause.

"It's been estimated that women suffer from hot flashes for one to five years, but I have seen several women in their 70s who were still dealing with them," says Wayne State University's Robert Freedman.

His research suggests that hot flashes are triggered when a woman's core body temperature rises slightly. (That's the temperature deep within the body, not what a regular thermometer measures.) Ordinarily, the rise wouldn't cause much discomfort.

"But in menopausal women, we think their tolerance for small increases in core body temperature, above what we call their thermoneutral zone, is greatly reduced," says Freedman. When that zone is breached, the result is flushing and sweating.

Researchers aren't sure why the tolerance for small changes in temperature shrinks during menopause.

"We don't have a good animal model to study hot flashes in menopause that occurs naturally, because very few animals live much beyond their reproductive years," notes Debra Barton, who studies non-hormonal treatments for menopausal symptoms at the Mayo Clinic in Rochester, Minnesota.

"The gold standard treatment is estrogen, which dramatically lowers the rate of hot flashes," says Freedman. But the hormone also raises the risk of heart disease, stroke, and dementia, so many women no longer take it.

While nothing curbs hot flashes as effectively as estrogen, several alternatives may provide some relief.

* Paced breathing. Using breathing exercises to relax can relieve hot flashes--sometimes the frequency, sometimes the intensity, sometimes both, says Freedman (see "Breathe After Me"). "In three of our studies, slow, controlled deep breathing cut the frequency of hot flashes by about half."

In his most recent trial, 24 women suffering at least five hot flashes a day were randomly assigned to practice either paced breathing or brainwave biofeedback. The number of hot flashes fell by half in the breathing group, but didn't budge in those doing biofeedback. (1)

And researchers in Sweden and at the Harvard Medical School have shown that relaxing through breathing can ease the intensity--and sometimes the frequency--of hot flashes. (2,3)

"We think the breathing expands the temperature zone a woman can tolerate, but we're not certain how," says Freedman.

* Keeping cool. "Running the air conditioning or a fan should help," says Freedman, because lower room temperatures can blunt the rise in body temperature. That may seem obvious, but it's good to know that research backs it up.

When six women who were averaging 10 hot flashes a day spent eight hours in a room kept at 89[degrees] F, they had 12 hot flashes that lasted around six minutes each. But during eight hours in a room kept at 66[degrees] F, the number of hot flashes dropped to three, lasted an average of about two minutes, and were about half as intense. (4)

The optimal room temperature will vary from woman to woman, says Freedman.

"Wearing loose, layered clothing ought to work, too, although we haven't tested it," he adds. That increases air flow around the skin, which cools the blood flow and evaporates sweat better.

* Losing weight and exercising. Menopausal women who are overweight are likely to suffer more hot flashes or night sweats than menopausal women who aren't. (5) "It's possible that increased body weight gives you more insulation," says Freedman, "so you're going to have a little bit higher core body temperature." Researchers haven't tested whether losing weight suppresses the flashes.

Women who exercise daily also have far fewer severe hot flashes. (6) That may be due to the exercise, or women may be more likely to exercise if they're having fewer severe flashes.

* Low-dose antidepressants. "The non-hormonal treatment with the best evidence of effectiveness is low doses of the antidepressants Effexor, Paxil, or Prozac," says the Mayo Clinic's Debra Barton.

"Well-controlled trials show that they decrease the frequency of hot flashes from 50 percent to 60 percent in a majority of woinen." (7) Since the drugs are used in doses lower than for the treatment of depression, "they have very tolerable side effects," says Barton.