Smokers’ breast-fed babies sleep less soundly
SMOKING mothers could be passing on more than just nutrients to their babies while breast-feeding. A new study published in the journal Pediatrics shows that the breast milk of cigarette smokers contains nicotine and can disrupt babies’ sleeping patterns. The study included 15 breast-fed infants aged between two and seven months of age, whose mothers were all current smokers. Each mother-child pair was tested on two separate days, one week apart. Mothers smoked one to three cigarettes (not in the presence of their child) on the first day, and refrained from smoking on the second day. On both days, mothers breast-fed their infants on demand over the next 3.5 hours. A sensor strapped to each infant’s ankle allowed researchers to measure activity and sleep time. Nicotine levels were measured in breast milk samples provided by the mothers before each feed. Total sleep time after feeding declined from an average of 84 minutes when mothers refrained from smoking to 53 minutes on the day they did smoke— a 37 per cent reduction. The level of sleep disruption was directly related to the dose of nicotine infants received from their mothers’ milk. Pediatrics 2007;120:497-502 (Mennella JA, et al) AVOCADOS should be included on the list of cancer-fighting fruits and vegetables, according to a new study in Seminarsin CancerBiology this week. Avocados are rich in vitamin C, folate, vitamin E, fibre and unsaturated fats. By studying oral cancer cells in the laboratory, scientists have found that the active plant chemicals (phytochemicals) in avocados can kill these cells while leaving normal cells untouched. Avocado extract can also stop pre-cancerous cells from becoming full-blown cancer. The authors claim that avocado could help to treat or even prevent cancer of the mouth, and the same may hold true for other types of cancer. One of the phytochemicals in avocado known as quercetin is able to stop the growth of prostate tumours in mice and decrease the severity of colon cancer in rats. SeminCancerBiol 2007;doi:10.1016/j.semcancer. 2007.04.003 (Ding H, et al) SMOKERS are more likely to develop Alzheimer’s disease or dementia than nonsmokers or those who smoked in the past, concludes a study in the current issue of Neurology. Researchers recruited 6868 people age 55 or older with no signs of dementia at the start of the study, and followed their progress for an average of seven years. Over that time, 706 of the participants developed dementia, with 555 of these classified as having Alzheimer’s disease. People who were current smokers at the start of the study were 47 per cent more likely to develop dementia and 56 per cent more likely to develop Alzheimer’s than people who had never smoked or past smokers. The increased risk of these disorders is most likely due to the damaging effects of smoking on blood vessels in the brain, say the authors. Neurology 2007;69:998-1005 (Reitz C, et al) OVERWEIGHT toddlers and those not attending day care are at higher risk of iron deficiency — a condition that can lead to learning and behavioral problems. The findings, published this week in Pediatrics , were based on a survey of 1641 American children aged one to three years old. Between 1999 and 2002, participating families were asked to complete an extensive survey and undergo medical examinations. The study found that 20 per cent of overweight toddlers were iron deficient, compared to 8 per cent of those at risk for being overweight, and 7 per cent of normal-weight toddlers. Only five per cent of those in day care had iron deficiency, compared to 10 per cent of toddlers not attending day care. Pediatrics 2007;120:568-575 (Brotanek JM, et al) BODY-BUILDING and nutritional supplements containing an antioxidant called N-acetylcysteine (NAC) may not be as safe as once thought. In the JournalofClinical Investigation this week, scientists have reported that taking NAC can cause blood vessels to sense that they are not getting enough oxygen. This can lead to dangerously high blood pressure in the arteries that carry blood to the lungs — a condition known as pulmonary arterial hypertension — and cause swelling of the right side of the heart. The research team gave NAC to mice in their drinking water for three weeks, and compared their blood pressure and heart function to that of mice that did not receive NAC. The next step, say the authors, is to work out whether the levels of NAC found in supplements may be harmful to humans. JClinInvest 2007;117:2592-2601 (Palmer LA, et al) OBESITY and eating disorders among girls could both be prevented using a new schoolbased overweight prevention program. Researchers have described the benefits of the program (5-2-1-Go!) in the latest issue of the ArchivesofPediatricsandAdolescent Medicine . The 5-2-1-Go! program promotes eating five servings of fruits and vegetables daily, limiting TV viewing to no more than two hours a day, and getting at least one hour of physical activity daily. The study took place in 13 secondary schools in Massachusetts between 2002 and 2004 and involved 1451 sixth- and seventh-graders (749 girls and 702 boys). Six schools used the 5-2-1-Go! program and seven used their usual health education program. Almost 4 per cent of girls receiving only their regular health education began vomiting or abusing laxatives or diet pills, but just 1 per cent of the girls in the 5-2-1-Go! program did so. The program reduced the risk of developing an eating disorder by twothirds in girls, but had no effect on the rate of eating disorders among boys. ArchPediatrAdolescMed 2007;161:865-869 (Austin SB, et al) Want to know more? Items are referenced where possible. A reference such as ‘‘ 2007;35:18-25’’ means the source article was published on pages 18-25 in volume number 35 of the publication, in 2007. A doi number or website address is used for research published on a journal’s website.
Iron: Day care children healthier