Study Links Sleep Patterns, Memory Loss
Women who sleep too little or too much in middle age or later may be more likely to have memory problems, a new study suggests. The study included more than 15,000 women, ages 70 or older. All of them were part of the long-term Nurses' Health Study. Women in this study answered questionnaires at regular intervals. Therefore, researchers knew a lot about their health and habits over time. Women who slept fewer than 5 or more than 9 hours each night had worse results on memory tests than those who slept 6 to 8 hours a night. The difference in memory was about equal to another 2 years of aging. Women whose sleep changed by more than 2 hours a night after middle age also had poorer memory than those who slept about the same amount over time. The study results show a link between sleep patterns and memory problems. They do not show that either one caused the other.