OAKLAND, Calif. July 11, 2012 - Weight loss that occurs in conjunction with a low-fat, high fruit and vegetable diet may help to reduce or eliminate hot flashes and night sweats associated with menopause, according to a Kaiser Permanente Division of Research study that appears in the current issue of Menopause.
This Women's Health Initiative study of 17,473 women found that women on a diet low in fat and high in whole grains, fruit and vegetables, who had menopausal symptoms, who were not taking hormone replacement therapy, and who lost weight (10 or more pounds or 10 or more percent of their baseline body weight) were more likely to reduce or eliminate hot flashes and night sweats after one year, compared to those in a control group who maintained their weight.
Many women experience hot flashes at some point before or after menopause, when their estrogen levels are declining, explain the researchers.
"While the mechanism is not completely understood, hot flashes and night sweats are thought to be caused by a complex interaction that involves fluctuating hormone levels, the hypothalamus region of the brain that regulates body temperature, brain chemicals and receptors, and the body's blood vessels and sweat glands," said Candyce Kroenke, ScD, MPH,a research scientist with the Kaiser Permanente Northern California Division of Research and lead author of the study.
Although previous research has shown that high body weight and weight gain are associated with hot flashes and night sweats associated with menopause, this study is the among the first -- and the largest-to-date -- to analyze whether weight loss on a diet designed to reduce fat and increase whole grains, fruit, and vegetable intake might ameliorate symptoms. It is also among the first to examine the influence of a dietary change on symptoms that include hot flashes and night sweats, said Kroenke.
"Since most women tend to gain weight with age, weight loss or weight gain prevention may offer a viable strategy to help eliminate hot flashes and night sweats associated with menopause," said Bette Caan, DrPH, a research scientist with the Kaiser Permanente Northern California Division of Research and the senior author of the study.
She explained that greater body fat provides insulation that may hinder heat loss, and hot flashes and night sweats provide a way to dissipate that heat.
"Weight loss, especially loss of fat mass but not lean mass, might also help alleviate hot flashes and night sweats," added Kroenke.
The investigators emphasize that further research is needed to better understand the relationship between diet, weight and hot flash/night sweat symptoms. They explain that the beneficial impact of a healthy diet alone (regardless of weight change) may also help ameliorate symptoms.
This study follows a related study published in March in the Journal of Clinical Oncology in which Kaiser Permanente researchers found that preventing weight gain after a breast cancer diagnosis may offer a viable intervention for relief of hot flashes. The researchers noted that intentional weight loss in breast cancer survivors requires further study.
The Women's Health Initiative Dietary Modification trial enrolled a diverse group of 48,835 post-menopausal women between 1993 and 1998 at 40 United States clinical centers to evaluate the effects of a low-fat dietary pattern on heart disease, breast and colorectal cancer, and fracture in postmenopausal women. The dietary intervention was aimed at reducing fat intake and increasing fruit, vegetable, and whole grain intake. Although weight loss was not a goal, participants assigned to the intervention group lost on average 4.5 pounds between baseline and year one, compared to the control group.
Additional authors on the study include: Marcia L Stefanick, PhD, with the Stanford Prevention Research Center; Garnet Anderson, PhD, with the Fred Hutchison Cancer Research Center in Seattle; Robert Brzyski, MD, PhD, with the University of Texas; Karen C. Johnson, MD, MPG, with the University of Tennessee Health Science Center; Erin LeBlanc, MD, MPH, with the Kaiser Permanente Center for Health Research; Cathy Lee, MD, with the University of California, Los Angeles; Andrea Z. La Croix, PhD, with the Fred Hutchison Cancer Research Center; Hannah Lui Park, PhD, with the University of California Irvine Department of Epidemiology; Stacy T. Sims, PhD, with the Stanford Prevention Research Center; Mara Vitolins, DrPH, with Wake Forest University in North Carolina; and Robert Wallace, MD, MS, with the University of Iowa College of Public Health. This research was funded by a grant from the National Heart Lung and Blood Institute.
About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and the society at large. It seeks to understand the determinants of illness and well-being and to improve the quality and cost-effectiveness of health care. Currently, DOR's 500-plus staff is working on more than 250 epidemiological and health services research projects. For more information, visit http://www.
About Kaiser Permanente
Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America's leading health care providers and not-for-profit health plans. Founded in 1945, our mission is to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve more than 9 million members in nine states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education and the support of community health. For more information, go to: www.kp.org/newscenter.