Many studies have focused on the influence of breast-feeding on child health. From analysis of data from the ELANCE cohort, Marie Françoise Rolland-Cachera, former researcher at Inserm and her co-workers in the Nutritional Epidemiology Research Team (EREN)[1] have shown that breast-feeding has a protective effect on the risk of obesity at 20 years of age. Researchers also emphasise that nutritional intake at the age of 2 years are critical in providing this beneficial effect. The results of the study are published in The Journal of Pediatrics

Recent studies have focused on the influence of breast-feeding on the risk of the child developing obesity: results showed beneficial but still inconclusive trends. They adjusted their results by considering various factors such as social categories, the weight of parents, age of diversification, etc. but until now no study had made adjustment for nutritional intakes subsequent to breast-feeding. It has now been shown that nutrition during the first two years of life had long-term consequences on health that can persist into adulthood.

© Fotolia

Researchers therefore studied relationships between breast-feeding and the risk of excess weight in adulthood by considering diet at 10 months and 2 years for children included in the ELANCE cohort.

The ELANCE Cohort started with children in good health, born in 1984 and 1985, recruited in Child Health Assessment Centres. Information on breast-feeding was gathered and nutritional intakes was assessed at ages 10 months and 2 years, then every two years up to the age of 20. At 20 years, several measurements were taken, including height, weight and body composition (measurements of lean mass and fat mass determined by impedancemetry).

The results show that the beneficial effect of breast-feeding is clearly seen when nutritional intake up to the age of 2 is considered and is significantly linked to a reduction in body fat at 20 years old. Furthermore, in the statistical model, higher fat intake at 2 years are linked to a reduction in fat mass at 20 years.

“Our study has therefore shown, for the 1st time, that if we take account of diet after the period of breast-feeding, the protective role of breast milk over the risk of obesity is clearly apparent,” explains Marie Françoise Rolland-Cachera, former Inserm researcher.

The diet of young children is often characterised by high protein intake and low fat intake; breast milk is rich in fat and contains a small proportion of protein. According to official recommendations, fats should not be restricted in young children in order to meet their high energy requirements for growth and rapid development of their nervous system. In particular, low-calorie dairy products with low fat content and a high proportion of protein are not indicated before the age of 2-3 years. Restricted fats may programme the child’s metabolism to deal with this deficit, but this adaptation will make it more likely become overweight when the fat intake increases later on.

“The beneficial effect of breast milk may be masked by a low-fat diet following breast-feeding, while a diet following official recommendations (no restriction in fats before the age of 2-3 years) allows its beneficial effect to appear” emphasises Sandrine Péneau, co-author of this work.

Researchers agree about the benefit of breast-feeding reducing the risk of future obesity and highlight the importance of a diet following official recommendations in relation to young children. A poorly-balanced diet after breast-feeding can compromise the benefit provided by breast milk and explain the controversies over its protective role against the risk of obesity.

In France, the levels of use of some psychoactive substances, especially alcohol, tobacco and cannabis, remain high among adolescents, despite progress in regulatory efforts to limit access to these products by minors, and regular prevention campaigns.

As part of preparing the Government Plan to combat drugs and addictive behaviours (2013-2017[1], the French Government’s Inter-Departmental Mission for the Fight against Drugs and Drug Addiction (MILDT) requested Inserm to prepare an overview of scientific knowledge regarding the susceptibility of adolescents (aged 10 to 18 years) to use psychoactive substances known to be consumed in significant amounts by young people (alcohol, tobacco and cannabis), as well as their susceptibility to develop other habits known to potentially cause problems (video/Internet games, gambling). The mandate from MILDT also included the analysis of strategies for effective prevention and intervention for this age bracket.

©Fotolia

To fulfil this remit, Inserm brought together a multidisciplinary group of experts in epidemiology, public health, human and social sciences, addiction, neuroscience and communication.

Analysis by the experts of data from the major surveys of use in France[2] and from the international scientific literature of the last ten years has enabled a better evaluation of the scale of the phenomenon in young people aged 10-18 years, and has helped to identify the major products involved and trends in use patterns, risk factors, and the main effects on health and associated social harm, and finally to describe those intervention strategies that have been evaluated, with a view to making recommendations to help prevent unsafe use and to help care for the adolescents involved.

The experts observed, in particular, a change in use and patterns of consumption of some psychoactive substances, such as, for example, the tendency toward occasional binge drinking that is developing among adolescents. Furthermore, they emphasise the greater sensitivity of this population to the neurotoxic effects of alcohol and cannabis compared to adults, something that makes adolescents especially vulnerable to the consequences of using these substances.

Adolescence, a period of vulnerability

Adolescence is accompanied by many physiological and physical changes, and is also a stage of complex psychological maturation and development. The young person progressively frees himself or herself from parental dependence, and develops a high level of social interaction; s/he seeks new experiences, which often include a certain resistance to established rules. Adolescence also constitutes a phase of curiosity, risk-taking and defiance.

Initiation into using legal psychoactive substances (alcohol/tobacco), as well as some illegal substances (cannabis etc.), occurs mainly during this period: only 6.6% of 17 year old adolescents have not tried any of these products. Adolescents show highly variable expectations/motives, usually differentiated along social and gender lines. They show little sensitivity to warnings regarding long-term risks to health, as they perceive them only as very remote risks that do not really concern them.

Most of the studies emphasise that for adolescents a positive first experience of psychoactive substances may influence subsequent use, encouraging regular use and the potential development of dependence.

The adolescent brain is more vulnerable to psychoactive substances than the adult brain. It has the distinction of being in a state of transition toward the adult state. The processes of brain maturation (which continue until approximately 25 years of age) lead to a heightened degree of vulnerability in adolescents to the neurotoxic effects of psychoactive substances in general. One area of the brain, the prefrontal cortex, which allows decision making and adaptation of behaviour to the situation, is especially involved in this maturation during adolescence.

Regardless of the product under consideration, early experimentation and initial drug use increase the risks of later dependence and more subsequent harm overall.

Psychoactive substance use[3] and associated harm

There are distinctions between unsafe drug use (endangerment), abuse or harmful use (injurious to health), and dependence. The term “addiction” generally covers dependence, but this is point is still being debated. For some authors, addiction is characterised by the persistent inability to control a behaviour, and the continuation of the latter despite the knowledge and presence of its harmful effects.

• Alcohol

In France, alcohol is the most consumed psychoactive substance in terms of level of experimentation, occasional use, and precocity of experimentation. In 2011, 91% of boys and girls had tried alcohol by the end of adolescence. In 2010, 58% of pupils aged 11 years stated that they had already tried an alcoholic drink.

Regular alcohol use (at least 10 times a month) is evident by the end of junior secondary school: in 2010, 7% of students in the 4th year of junior secondary school (approximate age 14-15) stated that they had consumed an alcoholic drink at least 10 times in the month prior to the survey. In 2011, 15% of boys and 6% of girls aged 17 years engaged in this regular drinking; however, daily alcohol consumption was observed in fewer than 1% of 17 year olds. A reduction in the difference between boys and girls can be noted between 2008 and 2011, as well as a slight increase in regular use.

Some participants had experienced alcoholic intoxication (drunkenness) from the start of secondary school. Among 4th year students at junior secondary school, 34% stated that they had already experienced such an episode. At 17 years of age, 59% of boys and girls stated that they had already been drunk in their lives, and 53% stated that they had been on a drinking binge (namely the consumption of at least 5 standard drinks on a single occasion) in the month prior to the survey. The rates of binge drinking in the month are continuing to increase: 46% in 2005, 53% in 2011.

In 2011, although France occupied a median position in Europe as regards binge drinking among 16 year olds, it was above the mean for regular alcohol consumption.

Harm and vulnerability among adolescents

Compared with adults, alcohol use among adolescents, especially massive intoxication, has more marked neurotoxic effects on the brain, both at the structural level (the production of new neurons/neurogenesis) and the functional level, as reflected by a greater interference with cognitive function (learning/memory). It has been documented that the morphological and functional impacts are greater for girls than for boys of the same age. The deficits observed in the medium term are proportional to the quantity of alcohol consumed.

Young people are less sensitive to the “negative” effects of alcohol (drowsiness, hypothermia, lack of motor coordination, etc.), but are more receptive to effects experienced as “positive” (disinhibition, facilitation of social interaction, etc.).

• Tobacco

In 2011, more than 2 out of 3 (68%) 17 year olds had tried tobacco.

Tobacco is the psychoactive product most used on a daily basis in adolescence: 30% of girls and 33% of boys are daily smokers at 17 years of age. According to data from 2011, daily use can be seen from the start of secondary school (8% for 3rd year students (approximate age 13-14 years) and 16% for 4th year students (14-15 years). A small increase in daily smoking was seen from 2008 to 2011.

In 2011, France was among the European countries with the highest levels of smoking among 16 year olds.

Associated harm

Apart from the high risk of dependence, tobacco has many well-known long-term consequences for health (respiratory and cardiovascular disease, cancers, etc.).

• Cannabis

In France, cannabis is the illegal substance most used during adolescence. In 2011, 42% of 17 year old adolescents had already smoked cannabis at least once (39% of girls and 44% of boys). Boys were heavier users than girls, who tried the product at an older age.

Initial experimentation, while very rare at entry into secondary school, was observed in the final years of junior secondary school (11% of 3rd year students, 24% of 4th year students), and in nearly one in two senior secondary school students in 2011.

In 2010-2011, 2% of 4th year, 6% of 5th year, and 7% of final year secondary school students (approximately 16-18 years of age) were using cannabis regularly (at least ten times in the previous month). Of 17 year old adolescents, 5% showed a risk of problem use or even dependence in 2011: 7% of boys and 3% of girls.

France, together with Canada, the Czech Republic, Switzerland, the United States and Spain, were among the countries with the highest prevalence of cannabis use among adolescents in 2011.

Harm and vulnerability among adolescents

In the hours following cannabis use, observed cognitive impairment involves attention, reaction time, working memory, and executive function. Furthermore, there is a significant correlation between use and various “acting out” behaviours (attempted suicide, bulimia, unsafe sexual behaviours, etc.) due to lowered inhibition.

This cognitive impairment tends to disappear within a month of stopping use. In adolescents, some of this impairment may persist, including after weaning, especially if use began before the age of 15 years. Long-term cognitive impairment is observed in proportion to dose, frequency, duration of exposure and age at first use of cannabis.

Regular use of cannabis has long-term effects that may affect school results and personal relationships.

Finally, cannabis use may also precipitate psychiatric disorders (anxiety disorders, depression, symptoms of psychosis and schizophrenia) in adolescents. This risk of psychotic disorders may be influenced by certain genetic factors, age of exposure and pre-existing vulnerability to psychosis (family history).

• Other substances and polydrug use

– Psychotropic drugs and other illegal products

In 2011, 41% of 17 year olds stated that they had taken at least one psychotropic drug in their lives. The most frequently tried psychotropic drugs are anxiolytic drugs (15%), sleep-inducing drugs (11%), and antidepressants (6%).

Experimentation with illegal products other than cannabis, such as amphetamines (including ecstasy), hallucinogenic mushrooms, LSD, cocaine or heroin appears only at the end of adolescence, in proportions from 3% for hallucinogenic mushrooms and cocaine to 0.8% for heroin. Most of this experimentation declined over the period from 2008 to 2011, especially for ecstasy.

At 17 years of age, almost no regular use of illegal substances other than cannabis was seen. Only inhaled products such as adhesives, solvents or poppers showed relatively high levels of experimentation at this age (9% said they had tried the latter).

– Energy drinks and alcopops

Energy drinks are consumed alone or mixed with alcohol, such as pre-mixed drinks (alcopops), mixtures of soft drinks and strong spirits, ranging from 5 to 8% alcohol by volume. At all ages of adolescence, boys are more frequent consumers of energy drinks than girls. In France, consumption of energy drinks has gone from 20% in the 1st year of secondary school to 36% in the 5th year.

Consumption of premixed drinks remains relatively less frequent than that of other main categories of alcoholic drinks. The infatuation of young people, especially girls, with this type of drink, highly sweetened and flavoured to mask the alcohol content, has been curbed by the imposition in France of a very high tax specifically on these products.

The combination of energy drinks with alcoholic drinks has been identified as a source of risk—it increases the consequences of drinking, particularly the risk of unprotected sexual relations. Furthermore, there may be a link between consumption of energy drinks combined with alcohol and the subsequent development of alcohol dependence.

– Polydrug use

At age 17, 4% of adolescents stated that they were daily tobacco smokers and regular consumers (at least 10 times per month) of alcoholic drinks, or daily smokers of tobacco and regular smokers of cannabis. Finally, 2% were regular polydrug users of tobacco, alcohol and cannabis.

Video/Internet game playing and gambling,[4] and associated harm

With regard to video/Internet games and gambling, one refers to social or recreational play or gambling (i.e. simple use), unsafe or problem play or gambling (i.e. abuse), and excessive or pathological play or gambling (i.e. dependence).

• Video/Internet game playing

In 2011, of the 80% of 17 year olds who stated having used the Internet in the previous seven days, approximately one in four used it for 2-5 hours a day; fewer than one in five for 5-10 hours, and one in ten used it for over 10 hours a day.

Depending on the country and the measurement method used, the prevalence of problem Internet use by adolescents may vary from 2 to 12%. In France, in 2011, the initial estimations show that 3-5% of 17 year olds may be involved.

Furthermore, 5% of 17 year olds may play video games for 5 to 10 hours a day. Although the total time spent playing games is higher for boys than for girls, the time spent in front of a screen is identical, since girls are heavier users of social networking.

While video games may have positive aspects, especially regarding the development of cognitive and spatial functions, they may also lead to a loss of control and behavioural problems. Among the different types of games, MMORPG (Massive Multiplayer Online Role Playing Games), usually played by boys, have been described as particularly addictive.

Of 17 year old players (all types of video games), 26% stated that they had encountered problems at school or at work, and approximately 4% stated that they had experienced money problems in the previous year because of their playing habits.

Associated harm

Apart from the time spent, which can sometimes prove to be very long, problems of a psychic and somatic nature may occur in cases of excessive use: sleep disorders, irritability, sadness, anxiety, isolation, deterioration in academic performance, problems with parents, etc. Problem use of video games may encourage use of substances (tobacco, cannabis, alcohol, energy drinks, etc.), and increase the risk of sedentary behaviour and overweight

• Gambling

In France as in most Western countries, gambling is illegal below the age of 18. However, according to international studies, minors do participate in gambling: 80% have already gambled in their lifetime, and 10-20% gamble weekly.

Initiation most often takes place in adolescence (even at the start of adolescence according to some authors), usually in the family circle; boys gamble more than girls, regardless of country studied or the reporting period.

In France, gambling among 17 year old adolescents was investigated for the first time in 2011: 44% had already gambled in their lifetime, and 10% had gambled that week. Of 17 year olds who had gambled in the previous week, 14% were gamblers in the moderate risk category, and 3% were excessive gamblers. Therefore, 1.7% of 17 year olds may be considered to have a moderate-risk or excessive gambling habit.

In France, gambling by adolescents mainly takes the form of scratch-cards and lottery tickets purchased from a tobacconist. The possibility of online gambling is especially attractive to young people, even minors. Nearly 14% of 17 year olds stated that they had gambled on the Internet at least once in the previous year.

Associated harm

Although the drift into addiction associated with gambling does not directly cause physical harm, it may have negative consequences (use of psychoactive substances, symptoms of depression and anxiety, suicide risk, financial loss, deterioration in academic performance, criminal activity, etc.). Studies evaluating harm from problem/pathological gambling in adolescence are still scarce, although it has been noted that the prevalence of problem/pathological gambling is higher among adolescents than adults.

Factors associated with problem use

Psychological factors (poor self-esteem, lack of self-confidence, etc.), socioeconomic, academic (disrupted schooling) and familial (intergenerational transmission of addictive behaviours) contribute to problem substance use or habits leading to addictive behaviour.

While adolescents from privileged backgrounds have higher levels of experimentation, young people from underprivileged social backgrounds or who have academic problems are at higher risk of engaging in regular excessive use of tobacco, alcohol or cannabis. Likewise, young people whose parents show addictive behaviours are at major risk of regular or excessive use: children of smokers are twice as often smokers themselves, children of excessive drinkers are twice as often regular drinkers themselves. It is the same for gambling.

Family cohesion (understanding between parents and children, parents’ knowledge of their children’s entourage and activities) reduces the risk of addictive behaviours in adolescents.

The experts also note the influence of the circle of friends and all the marketing products and advertising information produced by industries to encourage young people to buy legal addictive products (tobacco, alcohol, games in general). These advertisements and marketing tools may also limit the efficacy of prevention programmes aimed at young people.

Finally, the role of genetic factors in the risk of dependence needs to be emphasised. According to studies, a non-negligible share of the risk of developing an addiction might be attributable to genetic factors, and many candidate genes have been identified that are linked to addiction to individual substances.

Support for adolescents and prevention strategies

• Support for adolescents

Supporting the adolescent in the community depends on early intervention and strategies for risk reduction. Early intervention involves acting as early as possible so that unsafe behaviour does not take hold; strategies for risk reduction aim to reduce harm without seeking abstinence. Support in a consultation room setting and hospital/residential treatment is aimed at reducing use or even complete weaning from use.

Free anonymous “Clinics for Young Users” (CJC in French), operating since 2004, are dedicated reception and treatment facilities for young users of psychoactive substances. These clinics offer scientifically validated care plans. “Motivational counselling,” carried out in an outpatient setting, is based on the need to highlight and support the adolescent’s motivation so that s/he can change the addictive behaviour(s). Cognitive behavioural therapy (CBT) provides young people with alternative strategies for managing situations that contribute to addictive acting out, and family therapies support parents and their environment in mentoring and supporting the young person. Their efficacy has been demonstrated in the context of CJCs in France and Europe. They have also proven to be effective in serious situations, with those under 16 years of age, and where there are substantial behavioural problems.

Other approaches exist, such as psychodynamic approaches, centred on the individual and the strengthening of the self. They serve more often as a model for understanding than as a basis for action.

In cases where outpatient care has failed, residential care, which includes long periods in hospital and aftercare, enables the holistic evaluation and follow-up of adolescents (addictions and reintegration into work or education).

• Effective prevention strategies 

Several intervention strategies have shown beneficial effects in preventing or reducing the use of psychoactive substances. In particular, three types of interventions are usually included in programmes of validated efficacy: the development of psychosocial skills[5] in young people (management of emotions, decision-making, self-esteem) and their parents (improvement in communication, conflict management); multi-component strategies (including local players other than the school and the parents in addition to developing the skills of the young people and their parents).

There are also other types of interventions: remote support (computer or mobile telephone); media campaigns (especially for cutting down on tobacco), and legislative and regulatory actions aimed at limiting access to addictive substances.

Recommendations

The experts emphasise that the actions to be developed must focus primarily on alcohol and tobacco, and even cannabis, based on the levels of use and associated harm, which are greater than for other substances or for games.

Recommendations from the expert group have three main objectives:

– Prevent initiation, or delay the age at which it occurs 

The expert group recommends creating awareness among the public and the different players (young people, parents, those involved in the education, education-related, and medical sectors, etc.) of the adolescent’s vulnerability, and of the dangers associated with early initiation. This would involve emphasising, without sensationalising, messages describing the long-term impact on health, especially the brain, of rapidly consuming large amounts of alcohol, and of using cannabis regularly during adolescence. To modify the existing motivations, expectations and representations of these products, media campaigns must be accompanied by educational and legislative measures.

To prevent initiation, the experts also emphasise the importance of developing the psychosocial skills of adolescents. This might happen as part of group activities, including those in an academic setting, and be based on the age of first use of the various substances (10-12 years for tobacco, for example).

Adolescents remain very sensitive to messages conveyed by their parents. This is why the expert group recommends regularly informing parents on the harm associated with early use, the trends in use patterns among young people, and the marketing codes that target them and are aimed at encouraging use. It is a matter of helping the parents to adopt the most appropriate attitude for the situation.

By improving the training given to those involved in education, sports or recreation, all players in contact with adolescents may be informed of addiction issues, and trained in the early detection of problems and in the interventions that may be carried out.

In order to better control tobacco and alcohol sales, the experts recommend that purchase of these products be systematically accompanied by the presentation of an official document indicating age. They emphasise respect for and strengthening of laws to regulate advertising that promotes gambling at a young age. There should also be better visibility of the content of video games through the provision and improvement of logos specifying the age classification and content.

– Avoid regular use and damage to physical and social health

To avoid the development of addictive behaviour, the expert group recommends improving the detection of unsafe use and early intervention, strengthening first-line actions such as the “Clinics for Young Users,” by training staff in early intervention methods, and training some of them in treatments of proven efficacy (CBT, MDFT-type family therapy[6]). In cases where outpatient care has failed, adolescents with addictive behaviour should be offered care in specialised centres and in a residential setting.

The existence of mental distress or illness associated with excessive use or addictions requires a strengthening of the links between addiction services and paediatric/general psychiatry, especially those specialising in evaluation and early intervention in young adults, and with adolescent centres.

Finally, the expert group recommends improvement in cooperation between professionals in education, health and justice (liaison with children’s court judges and judicial protection of youth) to optimise guidance and care.

– Provide national and regional coordination of the territorial players

The expert group underlines the need for local support and the development of cross-cutting public management structures for addiction at local level in order to provide regional coordination for the territorial players. An inventory of the preventive actions on a regional scale in France would facilitate knowledge and dissemination of validated prevention strategies, and enable recommendations for schools and local governments. To ensure this coordination, the experts recommend the establishment of a committee for the evaluation of prevention programmes, which are rarely evaluated at present.

Recommendations for research have also been formulated:

Multidisciplinary, clinical and fundamental research, combined with longitudinal studies, should be supported in order to follow the trajectories of use and life so as to better understand use, risk/resilience factors, and health and social effects (consequences for education, for example) of psychoactive substance use or game-playing that leads to addictive behaviours.

Human and social science research, especially on the motivations and social habits of adolescents, seems necessary for more effective interventions.

The experts emphasise the interest of developing, evaluating and validating the tools for detection and intervention strategies for young people showing addictive behaviour.
They also recommend carrying out research on methods for preventing addiction among young people (role of digital technology, for example).

According to the results of an epidemiological study conducted jointly by French and English researchers at Inserm and University College London, men who drink more than 36 grams of alcohol (3.5 drinks) per day may have a faster decline in memory, which is reflected by a reduction in their attention and reasoning skills.
This study is published in the January 15, 2014, online issue of Neurology.

This new study involved 5,054 men and 2,099 women whose regular drinking habits were assessed three times over 10 years. Alcoholic drinks consumed included wine, beer and spirits. Then, when the participants were a mean age of 56, they took their first cognitive tests. These tests were repeated twice, 5 and 10 years later.

The researchers studied their memory skills and executive function, i.e. their ability to use their attention and reasoning skills in order to achieve a goal. The memory test required the subjects to recall in one minute as many words as possible from a list of 20 words spoken to them just before. Executive function was assessed using 3 tests: a logical reasoning test made up of 65 questions, and 2 tests of verbal fluency during which the participants had to write as many words as possible beginning with “S,” and as many names of animals as possible, respectively, in one minute.

Most of the research on the relationship between drinking and memory and executive function has been carried out on older people. “Our study is based on individuals with a mean age of 56 when the first cognitive tests were conducted, which is relatively young compared with previous studies on this subject. It suggests that heavy drinking is associated with a faster decline in all cognitive areas studied,” reports study author Séverine Sabia, PhD, of University College London in the United Kingdom.

For men, whereas the study found no difference in the decline of memory or executive function between non-drinkers, ex-drinkers, and light to moderate drinkers[1], heavy drinkers showed a more rapid decline in memory and executive function than moderate drinkers.

According to cognitive tests, this difference represented 1.5 to 6 additional years of cognitive decline. For example, a 55-year-old heavy drinker might have a decline in memory comparable to that of a 61-year-old individual.

In the present study, it was not possible to study heavy drinking by women at levels comparable to men, because there were too few women who drank in such quantity. However, a more rapid decline in executive function is suggested for women consuming more than 2 drinks.

The mechanisms involved in the association between heavy drinking and accelerated cognitive decline are not straightforward. One of the main hypotheses relates to brain and cardiovascular mechanisms that might exert effects over long periods of time. Indeed, heavy drinking is a known risk factor for vascular disease, and there are many arguments that various vascular factors contribute to cognitive decline. Moreover, heavy drinking may have both short-term and long-term deleterious effects on the brain, via neurotoxic and proinflammatory effects, and indirect effects through cerebrovascular disease and vitamin deficiency.

For the authors of this publication, “It would be interesting if we could repeat this type of study in order to evaluate the impact of heavy drinking on cognitive decline in women in greater detail. Moreover, new measurements of cognitive function will soon be available for the same participants. These will enable us to study whether the effect of heavy drinking on cognitive decline in mid-life (40-60 years) is even more obvious when the people grow older.”

From a public health point of view, this study agrees with previous work, and suggests that it is unlikely that moderate drinking exacerbates cognitive ageing. However, the results also show that heavy drinking in mid-life might lead to faster cognitive decline in later years.

Scientists at the Research Institute for Environmental and Occupational Health (Inserm unit 1085) in Rennes and Pointe-à-Pitre – in collaboration with the gynaecology and obstetrics department at the university hospital of Pointe à Pitre/Abymes and the Center for Analytical Research and Technology at the University of Liège – are publishing an article this week on the impact of chlordecone exposure on pregnancy duration and the risk of preterm birth (birth occurring before the 37th week of amenorrhoea).

The data collected and analysed come from the TIMOUN mother-child cohort in Guadeloupe. They were published in the American Journal of Epidemiology on 8 January 2014.

© fotolia

Chlordecone is a chlorinated pesticide that was used in the West Indies between 1973 and 1993 to prevent banana weevil. Its continuing presence in soil, river water and sediments has caused contamination of certain foodstuffs. The contamination of West Indian populations by this pesticide has been proven in previous studies. Chlordecone is now regarded as an endocrine disruptor.

To assess the impact of chlordecone exposure on pregnancy outcome, the team led by Sylvaine Cordier in Rennes and Luc Multigner in Pointe à Pitre set up a large mother-child cohort in Guadeloupe, called TIMOUN (which means ‘child’ in Creole ; see the insert on the next page).

From 2005 to 2007, over 1,000 women were enrolled in the study during the third trimester of their pregnancy, mainly at the university hospital of Pointe à Pitre/Abymes and the hospital in Basse Terre. Exposure to chlordecone was estimated from its concentration in the mother’s blood at the time of birth. The following factors were taken into account: age, parity, body mass index prior to pregnancy, the place of enrolment, the mother’s place of birth, marital status, level of education, gestational hypertension, gestational diabetes and other pollutants such as PCBs.

Maternal exposure to chlordecone was found to be associated strongly with shorter pregnancy duration and an increased risk of preterm birth, regardless of the method of onset of labour (spontaneous or induced). This could be explained by the hormonal, oestrogenic and progestogenic properties of chlordecone.

The consumption of contaminated foodstuffs is now the main source of exposure to chlordecone in the West Indies. While we have a relatively accurate understanding of the types of foodstuffs involved in chlordecone exposure, researchers believe that food sourced, produced, distributed and sold through unregulated channels, as well as food grown in contaminated soil in family gardens, is now a decisive factor in exposure levels.

Therefore, researchers argue that “all appropriate measures should be taken to reduce maternal exposure during pregnancy” and are encouraging the introduction of mechanisms to inform pregnant women about the types of food they should be avoiding during pregnancy (due to risky supply circuits).

Preterm birth can affect postnatal development. The children in the TIMOUN cohort are now being monitored, thus enabling us to better understand these effects, as well as those resulting from prenatal exposure to chlordecone.

The new report, “Maternal Mortality in France,” coordinated by Inserm Unit U953, Epidemiological Research Unit on Perinatal Health and Women’s and Children’s Health, announces a reduction in the rate of mortality due to postpartum haemorrhage—the leading cause of maternal mortality in France—for the 2007-2009 data compared to 2004-2006. Twenty recommendations have been formulated by the French National Expert Committee on Maternal Mortality[1] with the aim of raising awareness among health professionals and prospective parents, in consultation with the French National College of Obstetricians and Gynaecologists, the French Society of Anaesthetists/Obstetric Anaesthesia Club, and the French National College of Midwives. 

The epidemiological results of these studies are published in the November 2013 issue of Journal de Gynécologie Obstétrique et Biologie de la Reproduction.

Maternal death has become a very rare event, but remains a recognised and fundamental health indicator for a country, and a signal for health professionals and decision-makers of possible dysfunction in the care system. Maternal death is the death of a woman while pregnant or within 42 days, or one year, of termination of pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes.

From 2007 to 2009, 254 maternal deaths were identified, representing deaths of 85 women per year in France, from a cause related to pregnancy, childbirth or their aftermath, giving a maternal death rate of 10.3 per 100,000 live births.

A new, encouraging finding is that maternal death from postpartum haemorrhage—the leading cause of maternal mortality in France—decreased during the 2007-2009 period compared with 2004-2006.

According to the improved methodology for measurement, which must be put on a permanent footing, the rate of maternal mortality is generally stable. It seems possible to reduce it even further, since progress has been made, i.e. a reduction in deaths associated with haemorrhage and a decrease in suboptimal care.

“These results need to be examined in the light of the substantial mobilisation in the last ten years of researchers and clinicians, whose attention was drawn to the initial results of this survey in order to evaluate and improve care in relation to obstetric haemorrhage. However, the improvement must be pursued, since approximately 50% of these deaths were considered “avoidable” in France under current conditions, and given the widespread access of pregnant women to antenatal surveillance and quality care,” comments Marie-Hélène Bouvier-Colle, Emeritus Research Director at Inserm Unit U953, Epidemiological Research Unit on Perinatal Health and Women’s and Children’s Health.

Maternal risk factors

Maternal age and nationality, and the region where death occurs are the main individual factors identified as being associated with maternal mortality.

Age is a key factor in maternal mortality: over 50% of deaths involve women aged between 30 and 39 years, which can be explained by the fact that pregnancy is generally occurring at an increasingly higher age, and by the distinctly elevated risk of maternal death after 35 years.

Significant differences are observed between nationalities: women of Subsaharan nationality have the highest maternal mortality rate, at 22.4 per 100,000, i.e. twice as high as that of French women.

Rates vary for the different regions in France—the rate of maternal mortality is higher than the national average in the overseas departments (32.2 per 100,000) and in Ile de France (12.5).

Other risk factors for maternal death are obesity and multiple pregnancies.

Obstetric causes of death

The leading direct causes of maternal mortality are obstetric haemorrhage, which represents 18% of deaths, and, something relatively new, pulmonary embolism (11%), and complications of hypertension (9%).

The big change concerns the percentage of postpartum haemorrhage, which has declined by half since the last report (8%, or 1.9/100,000, compared with 16%, or 2.5/100,000, in 2004-2006). This encouraging result is probably due to the mobilisation of professionals for the last few years.

Adequacy of care and avoidability

Care was judged “suboptimal,” i.e. non-compliant with current recommended practice and knowledge, for 60% of deaths reviewed, compared with 72% between 1990 and 2000, which represents a significant decrease. Deaths from haemorrhage show the largest proportion of suboptimal care (81%).

Maternal deaths were judged “avoidable” in 54% of cases, i.e. a modification in the patient’s care or attitude in terms of medical opinion could have changed the fatal outcome (error or delay in diagnosis, delay or inappropriate first aid, inadequate treatment, delay in treatment or in intervention, and neglect of the patient). This rate, stable over time, is still mainly due to inadequate or delayed treatment, which implies that there is room for improvement.

These results have enabled the authors of the report to make 20 recommendations, among which we can mention:

– the importance of involvement of care-givers in the reporting and review of maternal deaths, in order to ensure a better knowledge of the national profile of these cases.

– risk assessment prior to conception and at the start of pregnancy, through prevention: vaccination against influenza for women who are pregnant or may become pregnant, risk assessment for a pregnancy where there is a preexisting pathology,

– medical examination of the pregnant woman outside the obstetric arena (examination of the heart, for example),

– maintaining vigilance after delivery when the mother returns home, i.e. informing her of the signs of venous thromboembolic events and arterial ischaemic stroke. A measure the importance of which is emphasised by Gérard Lévy, President of the National Expert Committee, especially given that women are returning home sooner and sooner after delivery.

– the importance of post-mortem examinations in cases of maternal death,

– other messages concern the medical management of obstetric haemorrhage, infection, hypertensive diseases, amniotic embolism, and venous thromboembolism.

Participation by members of the public in influenza surveillance via the Internet

Launched two years ago by the French GPs Sentinelles network (a joint research unit involving Inserm and the Université Pierre et Marie Curie) and the French Institute for Public Health Surveillance, the GrippeNet.fr website is back for a third consecutive year.

GrippeNet.fr complements traditional surveillance systems for influenza, which are fed information collected in private physician practices and hospitals. These data facilitate research initiatives (at European as well as national level) aimed at gaining a better understanding of influenza—research on risk factors, the role of age, impact of vaccination, spread of the disease on a Europe-wide scale, etc.

The principle of the GrippeNet.fr (https://www.grippenet.fr) website is to allow anyone living in metropolitan France, whether ill or not, to participate in influenza surveillance anonymously and voluntarily if s/he wishes to do so.

Last year, GrippeNet.fr had over 6,000 participants

Overview of the last season

During the last winter season, between 15 November 2012 and 21 April 2013, GrippeNet.fr enabled the collection of a large quantity of influenza-related data. A little over 6,000 Internet users participated, and nearly 85,000 questionnaires were completed. All departments in metropolitan France were represented, and, as in the first season, women and individuals aged 60 to 69 years were the most frequent participants. The representativeness of participants in the GrippeNet.fr study was the subject of a recent scientific publication (M. Debin et al. Evaluating the feasibility and participants’ representativeness of an online nationwide surveillance system for influenza in France. PLoS One. 2013 Sep 11;8(9):e73675).

Weekly collection of symptoms presented by participants allowed monitoring of the course of the influenza epidemic in the population. During the season, 29% of participants reported symptoms consistent with an influenza-like illness, compared with 23% during the first season. These figures may be explained by the fact that the 2012-2013 seasonal influenza epidemic was especially long, as shown by surveillance data from the Sentinelles network and the French Institute for Public Health Surveillance (InVS). The level of participants who consulted a physician for symptoms consistent with an influenza-like illness was 38% (These figures were similar to those seen during the first season). Of the regular participants in GrippeNet.fr, 34% were vaccinated against seasonal influenza, compared with 20% of the general population.

Objectives for the new season, 2013-2014

Although the number of participants last year was very encouraging (and actually higher than observed for some other European countries that had launched their population-based influenza surveillance schemes before France), it remains insufficient to enable the course of the influenza epidemic to be studied in different population subgroups at present, especially in men and young participants.

In order for GrippeNet.fr to provide the most reliable estimates possible, it is important for it to have the maximum number of participants, regardless of their state of health (low susceptibility to winter infections or often ill in winter), age, occupation, etc.

For this third season, several new elements can be noted:

• Improvement in the “feedback” given to participants in their personal space

After completing the weekly questionnaires, participants will now have access to personalised feedback on their results, with new graphic and stylistic elements. This system will enable participants to compare their own results (level of participation, symptoms presented, etc.) with those of other participants (of the same age group or gender, for example).

• Referral

Each participant may refer new participants via his/her account. All that is required is to complete the email address of individuals invited to participate in GrippeNet.fr. An email will be sent to them explaining the study and inviting them to participate.

• Discover new features throughout the season…

New features introduced during the 2013-2014 season will help to make participation in GrippeNet.fr more fun, in order to motivate more people to become involved in the project.

• RSS feed available on the www.grippenet.fr website, with maps and graphs from the study
• New actions planned for Corsica (with the support of the Corsican Regional Authority)

Well-designed physical exercise programmes may limit the risk of injury from falls in older people. According to an article published today by a team led by Patricia Dargent, Research Director at Inserm Unit 1018 (Centre for Research in Epidemiology and Population Health), not only can such exercise reduce the incidence of falls, it can also reduce their severity. For example, these programmes help to avoid hip fractures (neck of the femur), which require medical attention and lead to a loss of autonomy that is sometimes considerable in older people. 

These results, obtained from a survey of the literature, have been published in The British Medical journal.

©fotolia

From a certain age, some activities that had seemed routine can easily cause an accident (slipping on a carpet, climbing a step-ladder to replace a light-bulb, etc.) Moreover, whereas a fall may be of no great consequence for a healthy individual (who gets away with a hefty bruise), it can turn out to be serious and disabling for an older person. These injuries are very common, and constitute a major cause of long-term pain and a reduction in the ability to function. They also increase the risk of loss of autonomy and the need for nursing-home care, which constitutes a high economic cost.

Although the effect of exercise on the prevention of falls had already been demonstrated, its impact on the incidence of serious injury had not been considered. The latter was analysed by the researchers at Inserm, who reviewed all existing programmes to see if they were associated with a significantly lower risk of fractures or other serious injuries.

Their study included 17 studies carried out all over the world, involving 2,195 participants who exercised, and 2,110 who did not (control groups). The mean age of participants in these programmes was 76 years, and 77% of these participants were women.

Among the programmes reviewed, two consisted of doing tai-chi, whereas the others consisted of doing simple balance training exercises, most often combined with exercise to strengthen the muscles.

Results of the meta-analysis suggest that this type of programme helps to significantly reduce the incidence of falls leading to serious trauma, fracture, and/or requiring medical attention.

This study, the first of its kind, suggests that reducing the risk of falling, and improving the protective reflexes during a fall (such as putting out one’s hands to save oneself) by doing regular specific exercises might be a simple and feasible way to prevent fractures and other serious injuries in older people. The researchers see this as “additional evidence encouraging patients to participate in exercise programmes for falls prevention.”

Exposure to common air pollutants and traffic during pregnancy significantly increases the risk of restricted fetal growth, even at levels well below those stipulated in current European Union (EU) air-quality directives, according to one of the largest cohort studies of its kind published in The Lancet Respiratory Medicine.

The researchers estimate that for every increase of 5 micrograms per cubic meter (5µg/m³) in exposure to fine particulate matter during pregnancy, found in for example traffic fumes and industrial air pollutants, the risk of low birthweight at term rises by 18%. Importantly, this increased risk persists at levels below the existing EU annual air quality limit of 25µg/m³.

« Lower birthweight babies  is associated with health hazards during childhood and adult » explain Rémy Slama, Inserm research director and lead author of the study.“Our findings suggest that a substantial proportion of cases of low birthweight at term could be prevented in Europe if urban air pollution, particularly fine particulate matter, was reduced”*, explains Dr Marie Pedersen from the Centre for Research in Environmental Epidemiology in Barcelona, Spain. 

Pedersen was part of a team of European researchers coordinated by CREAL (Barcelona) and INSERM (Grenoble) to assess the impact of exposure to low levels of air pollution during pregnancy on low birthweight at term (<2500g, after 37 weeks of gestation) which has been linked with respiratory problems in childhood, as well as other diseases later in life. The study also looked at the impact on head circumference because of the potential effect on neurodevelopment.Using data from the European Study of Cohorts for Air Pollution Effects (ESCAPE), the investigators pooled data from 14 cohort studies in 12 European countries involving over 74 000 women who had singleton babies between Feb, 1994 and June, 2011.Air pollution concentrations of nitrogen oxides and particulate matter were estimated at the home addresses using land-use regression models. Traffic density on the nearest road and total traffic load on all major roads within 100m of the residence were also recorded.All air pollutants, particularly fine particulate matter (PM 2.5; with a diameter of 2.5 micrometers or less), and traffic density increased the risk of term low birthweight and reduced average head circumference at birth, after accounting for other factors like maternal smoking, age, weight, and education.Average exposure levels of PM2.5 during pregnancy in the study population ranged from less than 10μg/m³ to nearly 30μg/m³.The researchers estimated that if levels of PM 2.5 were reduced to 10µg/m³ (the WHO annual average air quality guideline value), 22% of cases of low birthweight among term deliveries could be prevented.According to co-author Professor John Wright, director of the Bradford Institute for Health Research in the UK, “The widespread exposure of pregnant women worldwide to urban ambient air pollution at similar or even higher concentrations than those assessed in our study provides a clear message to policy makers to improve the quality of the air we all share.”

The impact of depression on a person contracting cancer has long been suspected, without any study having definitely confirmed or rejected this theory. The links have now been investigated by Cédric Lemogne, a member of the team headed by Marie Zins (INSERM’s Mixed Research Unit 1018 “Epidemiology and Population Health Research Centre”, AP-HP, University of Versailles Saint-Quentin), who monitored 14,203 people between 1994 and 2009, including 1119 who developed cancer as diagnosed by a doctor. All of the absences from work for depression, certified by doctors, were recorded as well as many questionnaires measuring depressive moods. The results, which will be published in The American Journal of Epidemiology, do not indicate any significant association between a person experiencing the symptoms of depression during their lifetime and their subsequently contracting cancer.

© Fotolia

The continuing increase in incidences of cancer in France is a subject that concerns healthcare professionals, patients and their families. Although research has not yet solved all of the enigmas of the way in which cancer works, some have occasionally attributed the advent of cancer to a painful personal history. “Received ideas often become ingrained”, explains Cédric Lemogne, a psychiatrist at the Georges Pompidou European Hospital (AP-HP) who works in Professor Consoli’s unit (Université Paris Descartes). He is the principal author of a new study of the links between these two conditions.

“Ever since Hippocrates and the beginnings of medicine, the presence of “black bile” which gave rise to the term  melancholia or melancholy, has meant that people have associated the condition with the development of malign tumours. Today,  there are certain claims in circulation that depression could be a risk factor in cancer”

These have been supported by several scientific studies yet, in concrete terms, none of the existing meta-analyses has ever succeeded in confirming or rejecting these hypotheses.

The INSERM researchers explored the links by conducting the most robust epidemiological study. From this point of view, it was important to have data available, from quite a large cohort, that was validated for both the advent of cancer (validated cases of cancer, specific dates of the diagnosis, data for the incidence or otherwise of mortality) and with respect to depression-causing events.

The set of medical data from the 14,203 people who participated since 1989 in the GAZEL cohort of former employees of EDF-GDF [the gas and electricity companies] was collected between 1994 and 2009. The advent of depression-causing events was measured from the participants’ responses to a specific questionnaire provided every three years over a period of fifteen years and through diagnoses of depression by doctors when the employee was absent from work between 1989 and 1993.

On the basis of all these factors no significant association was found between the advent of depression and the subsequent advent of the five types of cancer monitored in this study (prostate, breast, colon, cancer associated with smoking, and cancer of the lymph glands or hæmatopoietic cancers (leukemias)). Consequently, being depressed does not expose a person to greater risk of cancer. 

On the other hand, the fact of being diagnosed with cancer can cause symptoms of depression. Quite apart from the results of this study, researchers emphasize that patients need reassurance. “How many times does one hear their nearest and dearest saying ‘you need to fight it, be strong to beat the cancer’. As it if were abnormal or even dangerous to feel despondent. I think that patients shouldn’t worry if they feel depressed. What is important is to follow all the treatments. Against cancer on the one hand and against depression on the other hand”.

This research benefitted from the support of the Public Health Research Institute and the Pasteur Mutualité Group’s Company Foundation.