Leave school early, and dementia more likely
Compiled by Dr Christine White HIGH school dropouts could be putting more than their education at risk: new research in Neurology has shown that people who don’t finish high school are more likely to develop dementia and Alzheimer’s disease in later life than those with more education. The Finnish study followed 1388 participants for an average of 21 years. They were divided into three levels: five or less years of education (low), six to eight years (medium) and nine or more years of education (high). Compared to those with a high education level, those with a low education level were 84 per cent more likely to develop dementia and 85 per cent more likely to get Alzheimer’s. Less educated people tend to have less healthy lifestyles, which could also affect the brain. But lower education was still linked to dementia and Alzheimer’s risk, regardless of body weight, physical activity, smoking, occupation or income. These findings support the idea that exercising the brain can protect it from damage. Neurology 2007;69;1442-1450 (Ngandu T, et al) WOMENwho have been pregnant have a reduced risk of developing breast cancer, and now scientists have discovered a possible explanation. During pregnancy, cells from the fetus can enter the mother’s body and survive for many years after the baby is born. To test whether this process — known as fetal microchimerism — could protect women from cancer, researchers recruited 82 women, 35 of whom had been diagnosed with breast cancer. They tested blood samples from each woman for the presence of male DNA, which was assumed to be from a previous pregnancy with a male baby. While 43 per cent of healthy women had male DNA in their blood, only 14 per cent of women with breast cancer had male DNA. Among the women who were known to have given birth to a son, those with male DNA in their blood were nearly six times less likely to develop breast cancer. Understanding how fetal cells can increase resistance to cancer may lead to improved treatments, say the authors of the study, published in CancerResearch this week. CancerRes 2007;67:9035-9038 (Gadi VK, et al) HAVING an after-school job teaches many life lessons, but new research in the American JournalofPublicHealth has found that it can also increase the chances of taking up smoking. The study found that 14- to 18-yearold adolescents were at an increased risk of starting to smoke when they started working, and those who worked more than 10 hours per week had started to smoke at an average age of 13 — one year earlier than nonworkers. Over a period of 10 years from ages eight to 18, information was collected on the working and smoking habits of 799 American students. During the final year of follow-up, nearly 40 per cent of the adolescents were employed as babysitters, fast food restaurant staff, or in retail positions, and 17 per cent were smokers. Those who worked were more than three times more likely to be smokers than those who didn’t. According to the authors, workplaces — especially those that employ young people — should be a target for smoking prevention programs. AmJPubHealth 2007;doi:10.2105/AJPH.2006.094045 (Ramchand R, et al) STRONG bones are less likely to be invaded by cancer cells, so increasing calcium intake could prevent the spread of breast cancer, concludes a new Australian study in Cancer Research this week. Using mice, Yu Zheng and colleagues at the ANZAC Research Institute in Sydney found that having low calcium levels increases the ability of breast cancer cells to invade bones. They argue that increasing calcium in the diet could improve the effectiveness of breast cancer treatments and perhaps even prevent secondary bone tumours. Mice were put on a diet containing either low or normal levels of calcium, and injected with breast cancer cells. Two weeks later, mice on a low calcium diet had 43 per cent more damage to their bones and 23 per cent larger bone tumours than those on a normal diet. CancerRes 2007;67:9542-9548 (Zheng Y, et al) OBESE women should gain less weight during pregnancy than is currently recommended, and severely obese women should actually lose weight during pregnancy, finds a new study in Obstetricsand Gynecology . The findings suggest that changing the advice given to obese women could improve their health and that of their babies. The American study involved 120,251 obese pregnant women, whose body mass index (BMI) before pregnancy was calculated as weight in kilograms divided by squared height in metres. A BMI over 30 is considered obese. Those with a BMI of 35 who gained fewer than the currently recommended minimum of seven kilograms during pregnancy were less likely to develop a dangerous condition called pre-eclampsia, less likely to need a caesarean delivery and more likely to have a baby of normal weight. ObstetGynecol 2007;110:752-758 (Kiel DW, et al) PREMATURE babies are prone to lung problems that can lead to long-term breathing troubles, but new research in GenomeBiology has found a way to better predict and treat this condition. Around 20 to 40 per cent of extremely premature infants will have abnormal lung development called bronchopulmonary dysplasia (BPD). Researchers obtained samples of umbilical cord from 54 infants born at less than 28 weeks gestation (more than three months early). Twenty of the infants developed BPD and the other 34 did not. Using gene chip technology, where 30,000 genes can be analysed at once, they found a similar pattern of gene activity in BPD infants as can be found in adult patients with chronic bronchitis and emphysema— conditions which also block airflow and make breathing difficult. Drugs that can treat these adult diseases could now be used to prevent lung disease in premature babies. GenomeBiol 2007;8 (Cohen J, 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.
Strong bones: Deter cancer