Harvard Health Content API

Many parents are still following infant sleep practices that could put their babies at risk of sudden infant death syndrome (SIDS), two new studies conclude. One study looked at survey data for nearly 400,000 infants. About two-thirds of the babies born at term were put to sleep on their backs. This position reduces the risk of SIDS. Preterm babies, born before 37 weeks of pregnancy, have a higher risk of SIDS than those born at term. But the survey showed they were less likely than full-term infants to be put on their backs to sleep (60% to 63%). The second study included 1,250 mothers of babies 2 months to 6 months old. They were interviewed about sleep practices for their babies. Overall, 72% of the babies were put to sleep on their backs. But 22% of black mothers put babies to sleep on their stomachs. About 28% of Hispanic mothers put the baby to sleep in the parents’ bed.

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.

Low vitamin D levels may increase the odds of developing aggressive prostate cancer, especially for black men, a new study finds. The study included 667 men. All of them were having their first prostate biopsy after an abnormal prostate exam or prostate-specific antigen (PSA) test. Researchers tested the men’s blood for vitamin D. Normal levels are 30 to 80 nanograms per milliliter (ng/ml). Most of the men, both white and black, had vitamin D deficiency. Black men with the lowest levels, less than 12 ng/ml, were 5 times as likely to have aggressive prostate cancer as those with normal levels. White men with the lowest vitamin D levels were 4 times as likely to have aggressive disease. Black men also were more than twice as likely to have any type of prostate cancer if their vitamin D levels were 20 ng/ml or lower.