7.1 Health and Sickness

Genetic and environmental factors safeguard middle childhood (about ages 6 to 11 years), the period after early childhood and before adolescence. One explanation comes from the evolutionary perspective: Genes protect children who have already survived the hazards of birth and early childhood so they can live long enough to reproduce (Konner, 2010). This evolutionary explanation may not be accurate, but for whatever reason, fewer fatal diseases or accidents resulting in death occur from age 6 to age 11 than at any other period of life (see Figure 7.1).

FIGURE 7.1 Death in Middle Childhood Is Rare Schoolchildren are remarkably hardy, as measured in many ways. These charts show that death rates for 5- to 14-year-olds are lower than those for children younger than 5 or older than 14, and are much lower than those for adults.

Slower Growth, Greater Strength

Unlike infants or adolescents, school-age children’s growth is slow and steady. Self-care is easy—from brushing their new teeth to dressing themselves, from making their own lunch to walking with friends to school. Once at school, brain maturation allows most of them to sit at their desks or tables and learn without too much difficulty.

Muscles, including the heart and lungs, become strong. With each passing year, children can run faster and exercise longer (Malina et al., 2004). As long as school-age children get enough food, they continue to grow 5 centimetres or more each year.

Medical Care

Immunization has reduced deaths dramatically, and throughout childhood, lethal accidents and fatal illnesses are far less common than a few years ago. For example, in Canada, before immunizations were introduced, about 9000 people, many of them young children, contracted diphtheria over any given five-year period. However, between 2000 and 2004 (well after the introduction of the diphtheria vaccine), only one case of diphtheria was reported in Canada (Public Health Agency of Canada, 2011b).

Furthermore, better medical care (diagnostic and preventative) has meant fewer children suffer with chronic conditions such as hearing impairments or anemia—both of which are half as frequent in middle childhood as they were two decades ago. Fewer children breathe second-hand smoke: Cotinine (a biomarker that reveals inhaled nicotine) in children’s blood declined by 28 percent in just one decade (1994–2004) (Morbidity and Mortality Weekly Report, July 11, 2008).

For all children, establishing good health habits in childhood protects health in adolescence and adulthood. This is especially important for children with serious, chronic conditions (such as diabetes, phenylketonuria [PKU], epilepsy, cancer, asthma, and sickle-cell anemia) who, as teenagers, may become rebellious and ignore special diets, pills, warning signs, and doctors (Dean et al., 2010; Suris et al., 2008).

Unfortunately, children in poor health for economic or social reasons are vulnerable throughout their lives. For low-income children, particularly, having a parent who is attentive and responsive (not only regarding health) makes a decided difference for adult health (Miller et al., 2011).

Physical Activity

The level of physical activity of children in middle childhood affects both their mental and physical health. The Health Behaviour in School-Aged Children Study (HBSC) examined the number of youth between the ages of 10 and 16 in 34 countries who engage in at least 60 minutes of physical activity a day for five or more days per week. Looking specifically at the data for 11-year-olds, youth from Ireland (31 percent of girls and 43 percent of boys), Austria (30 percent and 40 percent respectively), and Spain (26 percent and 41 percent respectively) fared best in the study. The least active groups were from the Russian Federation (11 percent of girls and 17 percent of boys), Denmark (10 percent and 16 percent respectively), and Italy (7 percent and 10 percent respectively). Canada ranked eleventh of the 34 countries, with 21 percent of 11-year-old girls and 31 percent of boys reporting at last one hour of daily physical activity. In addition, the results indicated that physical activity significantly decreases between ages 11 and 15 years (Currie et al., 2012).

Expert Eye-Hand Coordination The specifics of motor-skill development in middle childhood depend on the culture. These flute players are carrying on the European Baroque musical tradition that thrives among the Guarayo people of Bolivia.

DAVID MERCADO/REUTERS/CORBIS

Ian Janssen from Queen’s University, Ontario, and his international collaborators examined the data from an earlier version of this study. They found that lower physical activity and a greater amount of time spent watching television were associated with a greater likelihood of becoming overweight (Janssen et al., 2005).

Beyond the sheer fun of playing, some benefits of physical activity are immediate. For example, a Canadian study found that 6- and 7-year-olds who felt victimized by peers improved academically if they played sports (Perron et al., 2011). Active play contributes to the following:

• better overall health
• less obesity
• appreciation of cooperation and fair play, especially when playing games with rules
• improved problem-solving abilities
• respect for teammates and opponents of many ethnicities and nationalities.

Playing sports during middle childhood also has risks:

• loss of self-esteem (teammates and coaches are sometimes cruel)
• injuries (sometimes serious, including concussions)
• reinforcement of prejudices (especially against the other sex)
• increased stress (evidenced by altered hormone levels, insomnia).

Where can children reap the benefits and avoid the hazards of active play? There are three possibilities: neighbourhoods, schools, and sports leagues.

Why Helmets? Children participating in organized sports, such as these 6- to 8-year-old male and female hockey players in Vancouver, BC, need to take precautions to avoid injuries. The emphasis at this age is on skill development and having fun. Young children are not allowed to body check, and at all ages they wear helmets to protect against potential concussions.

JOHN LEHMANN/THE GLOBE AND MAIL/CP IMAGES

Neighbourhood GamesNeighbourhood play is flexible. Rules and boundaries are adapted to the context (out of bounds is “past the tree” or “behind the parked truck”). Street hockey, touch football, tag, hide-and-seek, and dozens of other running and catching games go on forever—or at least until dark. The play is active, interactive, and inclusive—ideal for children of both sexes and several ages. It also teaches ethics. One scholar notes:

Unfortunately, “not playing” is not only a consequence of ignoring the rules, but also of not having the time or a place to play. Parks and empty fields are increasingly scarce. A century ago, 90 percent of the world’s children lived in rural areas; now most live in cities or at the city’s edge.

To make matters worse, many parents keep their children inside because they fear “stranger danger”—although one expert writes that “there is a much greater chance that your child is going to be dangerously overweight from staying inside than that he is going to be abducted” (quoted in Layden, 2004). Homework and video games compete with outdoor play, especially in North America. According to an Australian scholar,

Idyllic Two 8-year-olds, each with a 6-year-old sister, are daydreaming or exploring in a very old tree beside a lake in Denmark—what could be better?

HENRIK WEIS/CULTURA/CORBIS

Canada and the United States are not the worst-offending nations in terms of using after-school time as study time instead of play time. South Korea, in particular, is known for the intensity of “shadow education,” which is extra tutoring that parents find for their children, hoping to improve their test grades later on (Lee & Schouse, 2011).

Organized SportSchools in North America often have after-school sports teams, which offer additional opportunities for activity, as do private or non-profit clubs and organizations. The organization known as Physical and Health Education Canada recommends that children receive at least 150 minutes of physical education (PE) a week. In reality, however, only 47 percent of parents report that their children receive enough activity through physical education classes at school (Canadian Fitness and Lifestyle Research Institute [CFLRI], 2011c).

Paradoxically, school exercise may actually improve academic achievement (Carlson et al., 2008), partly because of the increased blood flow to the brain. The Centers for Disease Control recommends that children be active (i.e., not sit on the sidelines awaiting a turn) for at least half of the time in their physical education classes (Khan et al., 2009). Many schools do not reach this goal.

About 75 percent of Canadian children engage in organized sports or physical activities (CFLRI, 2011a). The organized sport that parents sign their children up for varies depending on the family’s culture and socioeconomic status. For example, some children join hockey leagues, others learn to play basketball or soccer, and others take karate or swimming lessons.

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Unfortunately, children from low-SES families or with disabilities are less likely to belong to local clubs and teams, yet they would benefit most from the strength, activity, and teamwork of organized play. Even when joining is free, these children are less likely to be involved in extracurricular activities of any kind, and as a result, they do not reap the benefits of a more active lifestyle (Dearing et al., 2009). It is worth noting that Canadian children from higher-income families have a 25 percent higher participation rate than their peers from lower-income families (CFLRI, 2011b).

A VIEW FROM SCIENCE

Canadian Kids Get an “F” in Physical Activity

In the past several years, many scientific studies have established strong links between physical activity in middle childhood and the improved functioning of young bodies and minds (Bürgi et al., 2011; Davis et al., 2007). Demonstrated benefits include

• improved motor skills
• better aerobic fitness
• improved cognitive functions
• higher self-esteem.

Specifically, moderate to intense levels of physical activity have been shown to lower blood pressure and reduce body fat. Physically active children also appear to experience fewer problems with their mental health (Biddle & Asare, 2011).

With these proven benefits in mind, it is alarming that researchers have also documented steep declines over the last 50 years in physical activity levels among children in Canada and other countries. For example, data from the research organization Active Healthy Kids Canada (AHKC) show that from 2000 to 2010, the number of children who played outside after school dropped by 14 percent (AHKC, 2012b). The Canadian Fitness & Lifestyle Research Institute (2011b) reported that in 2010, outdoor play was greater among boys than girls, and almost twice as high among 5- to 12-year-olds as among 13- to 17-year-olds (see Figure 7.2). In addition, children of younger parents were more likely to play outdoors and participate in unorganized physical activity and sport than were children of older parents.

FIGURE 7.2 Older Kids Play Less Boys and girls of all ages participate in organized physical activities at a similar rate, however there are age and gender differences in terms of participation in unorganized physical activity and sport and outdoor play, as shown in this graph. What effects might this result have on physical and mental development in middle childhood?

Health Canada and the World Health Organization both recommend that 5- to 11-year-olds get at least 60 minutes of moderate to vigorous physical activity a day in order to enjoy the physical, mental, and emotional benefits outlined above (Tremblay et al., 2011). Sadly, very few Canadian children meet this minimum standard.

AHKC issues an annual bulletin in the form of a report card on activity levels of Canadian children. In 2012, the news was so dismal that AHKC entitled its report Is Active Play Extinct? and illustrated it with photographs of dinosaur skeletons juxtaposed with such childhood relics as paddle balls, skipping ropes, and hula hoops. For the sixth straight year, AHKC assigned Canadian children a grade of “F” in the category of physical activity (AHKC, 2012b).

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The data reported do indeed tell a grim story. Only 7 percent of Canadian children get the recommended 60 minutes of physical activity a day. This means the vast majority—93 percent—fail to meet even the minimum guidelines established by Health Canada. In fact, almost half of all Canadian children—46 percent—spend less than three hours a week in physical activity. This decline in physical activity correlates closely with rising rates of childhood obesity and the chronic diseases associated with these conditions, such as diabetes, heart disease, and high blood pressure (Anderson et al., 2006; Lambourne & Donnelly, 2011).

What has caused this remarkable falling off in activity levels among Canadian schoolchildren? According to the AHKC report, the two main reasons are

• safety concerns that lead to overprotective parenting
• dramatic increases in screen time for children and youth.

Even though Canadian crime rates are no higher today than in the 1970s, parents are more aware of cases of child assault and abduction due to greater media exposure (AHKC, 2012a; Silver, 2007). As a result, many parents have developed a “better safe than sorry” attitude. Whereas in past decades they allowed their children to play unsupervised for hours in empty lots or neighbourhood parks, today’s parents take a much more cautious approach, encouraging their children to stay inside where they are easier to monitor.

Children’s attraction to screen time means that most are only too happy to comply with the wishes of overly protective parents. One study indicates that Canadian children in Grades 6 to 12 spend an average of 7 hours and 48 minutes a day in front of the screens of their computers, televisions, video games, and smart phones (Leatherdale & Ahmed, 2011).

The result of parental worries over safety and their children’s fascination with electronic media is that Canadian kids spend about 63 percent of their free time being sedentary, getting no exercise at all. In fact, on weekends, when they have an abundance of time to spend as they please, they are actually less active than during the week (Garriguet & Colley, 2012).

Both AHKC (2012b) and the Heart and Stroke Foundation of Canada (2011) make a number of recommendations that they hope will reverse declining rates of physical activity among children:

• Provide greater access to playing fields, natural areas, and parks, along with equipment such as balls and skipping ropes to encourage active play.
• Encourage children to engage in modes of active transportation such as walking, cycling, and in-line skating or skateboarding. Facilitate this through improvements to sidewalks, bike lanes, and pedestrian crosswalks.
• Support school environments that encourage healthy activity through physical education programs.
• Put in place household rules and limits to discourage excessive amounts of screen time, and provide time for active sport and play.

As Dr. Mark Tremblay, director of the Healthy Active Living and Obesity Research Group at the Children’s Hospital of Eastern Ontario, noted, all children, regardless of age, should be engaged in regular forms of active play, where they can run, climb, jump, or cartwheel in open and safe places with their friends, like their parents once did. Active play not only improves children’s motor function, but also their levels of creativity, decision making, problem solving, and social skills (AHKC, 2012a).

Health Problems

Although few children are seriously ill during middle childhood, many have at least one chronic condition that might interfere with school, play, or friendship. Individual, family, and contextual influences interact with one another in the causes and treatments of every illness. To illustrate the dynamic interactions of every health condition, we focus on two examples: obesity and asthma.

Childhood ObesityBody mass index (BMI), as mentioned in Chapter 5, is the ratio of weight to height. Childhood overweight is usually defined as having a BMI above the 85th percentile, and childhood obesity as having a BMI above the 95th percentile of children of the same age (Barlow & the Expert Committee, 2007).

Childhood obesity is increasing worldwide, having more than doubled since 1980 in all three nations of North America (Canada, the United States, and Mexico) (Ogden et al., 2011). Statistics Canada reports that about one-third of 5- to 17-year-olds were classified as overweight or obese in 2009 to 2011. In addition, at ages 5 to 11 years, significantly more males than females were classified as obese (Roberts et al., 2012) (see Figure 7.3).

FIGURE 7.3 Different for Boys and Girls Obesity rates are higher for males than females, especially those ages 5 to 11 years.

Childhood obesity is linked to asthma, high blood pressure, and elevated cholesterol (especially LDL, the “lousy” cholesterol). According to the Canadian Diabetes Association (2012), 95 percent of children with Type 2 diabetes—a disease once thought to be an adult problem that has been increasing in children and youth over the past few decades—are overweight. Being overweight can affect children in other ways as well. As excessive weight builds, school achievement often decreases, self-esteem falls, and loneliness rises (Harrist et al., 2012). If obese children stay heavy, they become adults who are less likely to marry, attend college or university, or find work that reflects their ability (Han et al, 2011; Sobal & Hanson, 2011).

There are hundreds if not thousands of contributing factors for childhood obesity, from the cells of the body to the norms of the society (Harrison et al., 2011). More than 200 genes affect weight by influencing activity level, food preference, body type, and metabolism (Gluckman & Hanson, 2006). Having two copies of an allele called FTO increases the likelihood of both obesity and diabetes (Frayling et al., 2007).

But we cannot solely blame genes for today’s increased obesity, since genes change little from one generation to the next (Harrison et al., 2011). Rather, family practices and eating habits have changed. Obesity is more common in infants who are not breastfed, in preschoolers who watch TV and drink soft drinks, and in school-age children who are driven to school, sleep too little, and rarely play outside (Hart et al., 2011; Institute of Medicine, 2006; Rhee, 2008).

During middle childhood, children themselves may contribute to their weight gain by pestering parents for calorie-dense foods. In addition, social practices and policies have an impact (Branca et al., 2007): Communities and nations determine the quality of school lunches; the location of vending machines and fast-food restaurants; the prevalence of parks, bike paths, and sidewalks; and the subsidies for corn oil and sugar.

One particular culprit is advertising for candy, cereal, and fast food (Linn & Novosat, 2008); the rate of childhood obesity correlates with how often children see food commercials (Lobstein & Dibb, 2005). As one researcher at the Université du Québec à Montréal reported, the various advertising strategies used by companies have increased children’s temptation as marketers have given products effective appeal—they seduce (Laperrière, 2009). Such advertising is illegal or limited on children’s television in some countries.

Since every system (bio-, micro-, macro-, and exo-) is relevant, it is not surprising that parents blame genes or outsiders, while medical professionals and political leaders blame parents. The media contend that advertisements are only suggestions and parents or children are to blame if they follow harmful suggestions.

Same Situation, Far Apart: Healthy Eating Children have small stomachs, so they enjoy frequent snacks more than big meals. Yet snacks are often poor sources of nutrition. Culture can also play a role in the snacks that children eat. Here, a boy from Alberta eats cotton candy, while Japanese children eat takoyaki (an octopus dumpling).

JEFF MCINTOSH/CP IMAGES
BLOOM IMAGE/GETTY IMAGES

Rather than trying to zero in on any single factor, a dynamic-systems approach is needed: Many factors, over time, make a child overweight (Harrison et al., 2011). The answer to the first “What Will You Know?” question at the beginning of this chapter is precisely that: There are many reasons for childhood obesity and they are all interrelated.

AsthmaAsthma is a chronic inflammatory disorder of the airways that makes breathing difficult. Although asthma affects people of every age, rates are highest among school-age children and have been increasing in most countries for decades (Cruz et al., 2010).

In Canada, asthma is one of the most common chronic childhood diseases (Garner & Kohen, 2008). After increasing steadily for several decades, the childhood asthma rate in Canada has levelled off and even declined slightly over the past few years (see Figure 7.4). Statistics Canada reports that asthma rates for children between the ages of 2 and 7 years rose from 11 percent in 1995 to as high as 13 percent in 2001, but then fell to 10 percent in 2009 (Thomas, 2010).

FIGURE 7.4 A Change for the Better As this bar graph shows, asthma rates among Canadian children peaked around the year 2001 and have dropped somewhat since then. Environmental factors that may have influenced this decline include a fourfold decrease between 2000 and 2008 in the number of children aged 1 to 11 who were exposed to cigarette smoke at home (Thomas, 2010).

Many researchers are looking for the causes of asthma. A few alleles have been identified as contributing factors, but none acts in isolation (Akinbami et al., 2010; Bossé & Hudson, 2007). Several aspects of modern life—carpets, pollution, pets inside the home, airtight windows, parental smoking, cockroaches, less outdoor play—also contribute to the increased rates of asthma (Tamay et al., 2007), but again no single factor is the cause.

Some experts suggest a hygiene hypothesis, proposing that “the immune system needs to tangle with microbes when we are young” (Leslie, 2012). Parents are so worried about viruses and bacteria that they overprotect their children, preventing minor infections and diseases that would strengthen their immunity. This hypothesis is supported by data showing that (1) first-born children develop asthma more often than later-born ones, perhaps because parents are more protective of first children than of later ones; (2) children growing up on farms have less asthma and other allergies, perhaps because they are exposed to more viruses and bacteria; and (3) children born by C-section (very sterile) have more asthma. However, none of those prove the hygiene hypothesis. Perhaps children living on farms are protected by drinking unpasteurized milk, by spending more time outdoors, or by genes that are more common in farm families (von Mutius & Vercelli, 2010).

The incidence of asthma increases as nations get richer, as seen dramatically in Brazil and China. Better hygiene is one explanation, but so is increasing urbanization, which correlates with more cars, more pollution, more allergens, and better medical diagnosis (Cruz et al., 2010). One review of the hygiene hypothesis notes that “the picture can be dishearteningly complex” (Couzin-Frankel, 2010)

Prevention of Health ProblemsThe three levels of prevention (discussed in Chapters 5 and 6) apply to every health problem, including the two just reviewed: obesity and asthma.

Prevalence of Asthma The use of asthma inhalers by children in school is quite common. The causes of asthma are still unknown, although researchers point to genetic factors, parental smoking, house pets, pollution, and lack of exposure to viruses and bacteria as possible factors.

KATHY MCLAUGHLIN/THE IMAGE WORKS

Primary prevention requires changes in the entire society. Better ventilation of schools and homes, less pollution, fewer cockroaches, fewer antibiotics, and more outdoor play would benefit everyone. ParticipACTION’s “Bring Back Play” initiative to promote outdoor play use is an example of primary prevention if it makes everyone more likely to be active.

Secondary prevention decreases illness among high-risk children. If asthma or obesity runs in the family, then breastfeeding for a year, regular and sufficient sleep, and low-fat diets would help prevent some illness. Annual checkups by the same pediatrician—who tests vision, hearing, weight, posture, blood pressure, and more—can spot potential problems while secondary prevention is still possible.

Finally, tertiary prevention treats problems after they appear. For asthma, for instance, that means prompt use of injections and inhalers. Even if tertiary prevention does not halt a condition, it can reduce the burden on the child.