Review on October 23, 2008
Night sweats, scientifically termed hyperhidrosis, are caused by a variety of factors, affecting both men and women of all ages. Fluctuations in hormones, certain medications, alcohol and spicy foods can all lead to drenched sheets in the middle of the night. While all of these triggers may influence the incidence of night sweats in menopausal women, caffeine has been shown in numerous studies to have a strong effect on their frequency. This is particularly insidious as recent studies show that 90% of American adults are coffee drinkers.
On one level, as a stimulant, caffeine increases the activity of the sympathetic nervous system. When the sympathetic nervous system goes into a higher level of activity, this results in a corresponding increase in sweating; hence the occurrence of night sweats. According to recent research, including one recent study conducted by the Geriatric Psychopharmacology Program at the University of Pittsburgh Medical Center, an increase in estrogen levels can inhibit the caffeine metabolic rate. This can be particularly of interest to menopausal women who may be considering hormone replacement therapy.
As estrogen inhibits the metabolic rate of caffeine, simultaneous use of caffeine and estrogen can increase the serum concentration of both substances in the body. As a result of this higher concentration, the stimulant effect of caffeine is intensified, leading to a higher level of activity of the central and sympathetic nervous systems, leading to increased sweat, and ending up in night sweats.
In addition, caffeine has been shown by leading researchers to increase the production of stress hormones such as adrenaline, cortisol and norepinephrine, which activate the body's "fight or flight" response system, increasing body temperature. The hypothalamus, the part of the brain that controls body temperature is over-stimulated, causing an unnecessary "cool down" response, and leading to a higher incidence of both hot flashes and night sweats.
Also detrimental to women, particularly of menopausal age, is that caffeine interferes with the absorption of minerals such as calcium, potassium, iron and magnesium, leading to further health problems down the road. Night sweats could be the least of a woman's problems in the event of overconsumption of caffeine.
- Mold, James W., et al. "Prevalence and Predictors of Night Sweats, Day Sweats, and Hot Flashes in Older Primary Care Patients: An OKPRN Study." Ann Fam. Med. 2.5 (Sept. 2004): 391-397.