Trouble identifying smells could be an early indicator to Alzheimer’s
SMELL may not be the most important of the five senses, but trouble identifying odours could be an early sign of Alzheimer’s disease. According to new research in the Archivesof GeneralPsychiatry , older adults who have difficulty recognising common odours may be at greater risk of developing cognitive impairment — a decline in thinking, learning and memory that can precede Alzheimer’s. The study involved 589 older adults with an average age of 79.9, who did not have cognitive impairment at the start of the study. They were given a smell identification test, during which 12 familiar odours were placed under their nose. They were asked to match each odour to one of four possible alternatives, and were scored from one to 12 based on the number of correct answers. Over the following five years, 177 people (30.1 per cent) developed mild cognitive impairment. The risk of developing the condition increased as odour recognition decreased, so that those with the lowest scores on the test (below 8) were 50 per cent more likely to develop the condition than those with the highest scores (11 or 12). ArchGenPsychiatry 2007;64:802-808 (Wilson RS, et al) SMOKING just one cigarette is enough to cause nicotine addiction in young people, claims a new study in the Archivesof PediatricsandAdolescentMedicine . The study found that 10 per cent of young people who become hooked on cigarettes are addicted within two days of first smoking, and 25 per cent are addicted within a month. Researchers monitored 1246 Grade Six students over four years. Each student was interviewed three times about smoking, symptoms of addiction (difficulty quitting, strong urges to smoke) and nicotine withdrawal symptoms (cravings, restlessness, irritability, and trouble concentrating). There were 217 students who inhaled cigarette smoke during the study. Of these, 127 showed symptoms of nicotine dependence and half were addicted by the time they were smoking only seven cigarettes per month. Among the 83 smokers who developed the highest level of addiction, half had done so by the time they were smoking 46 cigarettes per month. ArchPediatrAdolescMed 2007;161:704-710 (DiFranza JR, et al) TEENAGERS from low-income families are more likely to suffer from migraines than the children of higher income earners, finds a study in the current issue of Neurology . Researchers surveyed 18,714 adolescents and their parents. A total of 1178 adolescents reported migraine. In families with no history of migraine, but with an annual income of less than $US22,500 ($A26,334), the risk of teenage migraine was 4.4 per cent. But in families with no migraine history and a higher annual income of $US90,000 ($A105,337) or more, the risk was only 2.9 per cent. Possible factors associated with low socioeconomic status, such as stress, poor diet or limited access to medical care may be responsible for this difference, say the authors. Neurology 2007;69;16-25 (Bigal ME, et al) CHILDREN born following in-vitro fertilisation (IVF) may grow taller and have a healthier metabolism than other children in their age group, according to research published online this week in the Journalof ClinicalEndocrinologyandMetabolism . These improvements, which can be seen as early as mid-childhood, may be due to subtle changes to the children’s genes that can occur during the IVF process. Researchers recruited 69 healthy children aged four to 10 conceived using IVF, and a control group of 71 naturally conceived children of similar ages. They measured height, weight and a range of factors in the children’s blood including glucose, insulin and cholesterol. After accounting for parents’ heights, IVF children were taller on average than naturally conceived children. They also had higher levels of growth factors in their blood, and more high-density lipoprotein (HDL, or ‘‘ good’’ cholesterol). JClinEndocrinolMetab 2007;doi:10.1210/jc.2006-2465 (Miles HL, et al) ALCOHOLICS who took a new drug to curb their urge to drink reported fewer heavy drinking days than those taking an inactive placebo. The Finnish study, published in the journal Alcoholism:ClinicalandExperimental Research , involved 403 heavy drinkers who took either the drug nalmefene or a placebo whenever they had the urge to drink. Before the study, the average number of heavy drinking days (five or more standard drinks for men and four or more drinks for women) each month was 15.5 in the nalmefene treatment group and 16.2 in the placebo group. During the three-month treatment period, the average number of heavy drinking days per month was 8.6 to 9.3 for the nalmefene group, and 10.6 to 12.0 for the placebo group. While the drug reduced alcohol consumption, side effects included nausea, insomnia, fatigue and dizziness. AlcoholClinExpRes 2007;31:1179-1187 (Karhuvaara S, et al) EATING small amounts of dark chocolate every day can reduce blood pressure, without causing weight gain or any other side effects, say the authors of a new study in the Journal oftheAmericanMedicalAssociation . Previous studies have shown that eating large amounts of cocoa-containing foods can lower blood pressure, due to the action of beneficial chemicals called polyphenols. But the long- term effects of regularly consuming small amounts of these foods were unknown. The trial included 44 men and women aged 56 to 73 with high blood pressure (BP 130/85 to 160/100). Participants were randomly allocated into two groups. For 18 weeks, one group received 6.3g (30 calories) per day of dark chocolate containing 30mg of polyphenols, and the other group received the same amount of polyphenol-free white chocolate. In 18 weeks, dark chocolate significantly reduced blood pressure without affecting body weight or levels of sugar and fats in the blood. There was no change in blood pressure among those in the white chocolate group. JAMA 2007;298:49-60 (Taubert D, 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.