“Aging, we are all doing it,” a subway poster proclaims. That poster is designed to make us think. Although we are all aging, few of us realize it because organ reserve and homeostasis (described in Chapter 11) allow declines to be unnoticed at least until middle adulthood and perhaps later.

Typically, 30- to 65-year-olds feel five to ten years younger than their chronological age and think that “old” describes people significantly older than they themselves are (Pew Research Center, June 29, 2009; see Figure 12.1).

Most adults consider themselves strong, capable, and healthy. Economic analysis supports this perception: Adults ages 26 to 60 contribute more to the society than those older or younger, adding a surplus to aid those not yet, or no longer, “in their prime” (Zagheni et al., 2015).

Allostatic load, also described in Chapter 11, builds quickly or slowly, so some people at the end of this stage (age 65) seem decrepit while others seem youthful. Measured by 18 indicators of health and aging—as well as appearance in photographs—some people age 3 years per chronological year, and some people less than 1 year—even though 12 months have passed (Belsky et al., 2015). Nutrition, exercise, medical care, pollution, climate, and probably personality and cognition influence how long, how strong, and how full each adult life is.

429

Genes are important, too, of course. Senescence, as the aging process is called, is genetically coded for every species. Our human genes cause us to live much longer than dogs but not as long as some tortoises.

However, within each species, the environment (both personal choices and the social context) is the main reason one individual lives twice as long and with more vitality than another. Variation in aging among humans, currently and over the centuries, is vast, but this is not primarily because of genes (Robert & Labat-Robert, 2015). Some specifics follow.

Adults do not move their legs, arms, or even hands as much as adults did a century ago, thanks to many modern devices, from the automobile to the TV remote. Fortunately, adults are becoming increasingly aware of the need to be active. More (51 percent) meet the U.S. weekly goal of 150 minutes of moderate exercise or 75 minutes of intense exercise than adults did 15 years ago (41 percent) (National Center for Health Statistics, 2014).

Regular physical activity protects against serious illness even if a person smokes, drinks, or overeats (all discussed soon). Exercise reduces blood pressure, strengthens the heart and lungs, and makes depression, osteoporosis, heart disease, arthritis, and some cancers less likely. Health benefits from exercise are substantial for men and women, old and young, former sports stars and those who never joined a team (Aldwin & Gilmer, 2013).

By contrast, sitting for long hours correlates with almost every unhealthy condition, especially heart disease and diabetes, both bringing additional health hazards beyond the disease itself. Even a little movement—gardening, light housework, walking up the stairs or to the bus—helps. In fact, intensity is unnecessary: Regular exercise is (Ross et al., 2015).

The close connection between exercise and physical and mental health is well known, as is the influence of family, friends, and communities on movement. Neighborhoods high in walkability (paths, sidewalks, etc.) reduce time driving and watching television (Kozo et al., 2012). This relationship between the surroundings, exercise, and health is causal, not merely correlational, because exercise strengthens the immune system (Davison et al., 2014). Moreover, active people feel energetic, which increases other good habits.

Drugs can be beneficial or harmful at every age. In adulthood, ideally, adults learn to use needed drugs, at the right dose, and avoid the others.

MEDICATION In the past month, in the United States, more than a third (39 percent) of 25- to 44-year-olds, and two-thirds (66 percent) of 45- to 64-year-olds took at least one prescription drug, according to surveys completed between 2007 and 2010. (Rates may be higher now.) About half of those prescriptions were for chronic conditions (such as high blood pressure) and about half for pain. Prescribed psychoactive drugs were also common: 12 percent of young adults and 20 percent of those 45–64 took antidepressants (National Center for Health Statistics, 2014).

430

Over the past 50 years, prescription medication has cut the adult death rate in half and markedly reduced disability. Childhood diabetes (type 1), for instance, was once a death sentence; now diet and insulin allow diabetics to reach the highest levels of success, as Supreme Court Judge Sonia Sotomayor did (Sotomayor, 2014). She began injecting herself at age 7; now she takes newer, less uncertain medication every day.

There is no accurate tally of over-the-counter drugs, but almost every adult frequently takes vitamins, analgesics, laxatives, antihistamines, or some other medication. One benefit of growing older is wisdom regarding drug use: Adults tell each other what works, doctors adjust their prescribing, and each person knows his or her personal reactions to various drugs. We all choose how to respond to headaches or colds.

Research on coffee finds that adults make choices regarding that drug, too. The effect of coffee varies genetically, so some adults learn to avoid it and others to drink several cups a day (Cornelis et al., 2015). For some, coffee reduces various problems, including Type 2 diabetes (Palatini, 2015). For others, it disrupts nighttime sleep and undercuts daytime efficiency. Adults adjust accordingly.

ILLEGAL DRUGS Lessons learned from experimentation are also apparent with recreational drugs. As described in Chapter 11, abuse of illegal drugs decreases markedly over adulthood—often before age 25 and almost always by age 40.

Unfortunately, abuse of prescribed medication is increasing. One reason is that such drugs are first given by a doctor to reduce pain, insomnia, or psychological distress. That makes it harder for adults to recognize the early signs of addiction, and thus some seek more prescriptions rather than trying to quit. Danger ahead.

For example, after the trial of a man (age 33) who killed four people to get pills for himself and his addicted wife (age 30), the local attorney general said, “the genesis of the current prescription pill and heroin epidemic lies squarely at the feet of the medical establishment,” (Spota quoted in James, 2012). Of course, doctors feel unjustly accused for illegal prescription use. Addiction of all kinds raises the question as to who is to blame—and answers range from the addict to the dealer or doctor to the entire society.

TOBACCO Society is pivotal for the drug that causes more deaths than any other, tobacco. About 70 percent of the lung cancer deaths worldwide, and 90 percent in industrialized nations, are caused by cigarettes (Ezzati & Riboli, 2012). Many other diseases are traced to tobacco as well.

Cigarette smoking is a classic example of cohort effects. During World War II (1941–1945), American soldiers (always men) were given free cigarettes. Then in 1964, the U.S. Surgeon General first reported on the health risks of smoking, with many follow-up reports in the next few decades. As a result, many former soldiers quit.

Meanwhile, some women celebrated another historical happening, women’s liberation, by smoking—-encouraged by cigarette advertisements. (One brand launched in 1968, Virginia Slims, used the slogan “you’ve come a long way baby”).

431

In the 1960s, more than half of U.S. adult men and more than a third of women smoked. By 2012, data showed that both sexes had decreased smoking but that fewer women had quit (see Figure 12.2).

Overall, 22 percent of adult men (age 25–65) and 18 percent of women are now smokers, with rates peaking in the 20s and then decreasing gradually with maturity (National Center for Health Statistics, 2014). By age 60, more adults are former smokers than current smokers.

A half-century ago in the United States, five times as many men as women died of lung cancer. Because of cohort changes in when men and women started smoking, lung cancer has become an equal opportunity disease: “women who smoke like men die like men who smoke” (Schroeder, 2013, p. 389) (see Figure 12.3).

Not only cohort but also culture has a strong effect on both smoking and gender differences. Almost half the adults of both sexes in Germany, Denmark, Poland, Holland, Switzerland, and Spain smoke. A joke in Europe is “if you want to stop smoking, go to America.”

In poor nations, rates of smoking as well as lung cancer increase with income, because it costs money to buy cigarettes. Traditionally in Asia, women rarely smoked, but their rates are increasing rapidly (Lortet-Tieulent et al., 2014).

The World Health Organization calls tobacco “the single largest preventable cause of death and chronic disease in the world today,” with one billion smoking-related deaths projected between 2010 and 2050, most in low-income nations where rates of abject poverty are declining (Blas & Kurup, 2010, p. 199).

ALCOHOL The harm from cigarettes is dose-related: Each puff, each day, each breath of secondhand smoke makes cancer, heart disease, strokes, and emphysema more likely. No such linear harm results from drinking alcohol.

432

In fact, some research reports that alcohol can be beneficial: Adults who drink wine, beer, or spirits in moderation—never more than two drinks a day—live longer than abstainers. Some scientists consider this to be a misleading correlation, because some of the abstainers were heavy drinkers who already damaged their health and then quit (Chikritzhs et al., 2015; Knott et al., 2015). Everyone agrees that excessive drinking is harmful.

Alcohol use disorder destroys brain cells, is a major cause of liver damage and several cancers, contributes to osteoporosis, decreases fertility, and accompanies many suicides, homicides, and accidents—while wreaking havoc in families. Even moderate consumption is unhealthy if it leads to smoking, overeating, casual sex, or other destructive habits.

Alcohol abuse shows age, gender, cohort, and cultural differences. For example, the risk of accidental death while drunk is most common among young men: Law enforcement has cut their drunk-driving rate in half. However, ongoing harm to families is more prevalent when men or women who are addicted to alcohol are middle-aged parents (Blas & Kurup, 2010).

In general, low-income nations have more abstainers, more abusers, and fewer moderate drinkers than more affluent nations (Blas & Kurup, 2010). In developing nations, prevention and treatment strategies for alcohol abuse have not been established, regulation is rare, and laws are lax (Bollyky, 2012). Thus, alcohol is particularly lethal as national income falls.

Weight trends are the opposite of alcohol use disorder. Internationally, overweight increases as nations become richer, and over the years of adulthood, obesity increases.

Obesity increases the risk of almost every disease. Consider just one example. Type 2 (adult onset) diabetes is increasing worldwide, causing eye, heart, and foot problems as well as early death. Genes for diabetes are often activated by body fat. Nature and nurture again.

NATIONS COMPARED In the United States, adults gain an average of one to two pounds each year. The biological reason is that between ages 20 and 60 metabolism decreases by one-third and digestion becomes less efficient.

Over 40 years of adulthood, that adds 40 to 80 pounds. As a result, more than two-thirds of U.S. adults (between 25 and 65) are overweight, defined as a body mass index (BMI) of 25 or more. Worse, a third are more than overweight; they are obese, with a BMI greater than 29 (National Center for Health Statistics, 2014).

433

Rates are lower elsewhere, but worldwide half a billion adults are obese. Obesity rates have plateaued in the United States but are accelerating in many other nations, particularly in Africa and Asia, where past malnutrition taught adults to eat whenever food was available. Worldwide, malnutrition was once the main nutritional problem; now obesity is (World Health Organization, 2013).

National context is crucial. In a surprising example, an economic crisis in Cuba from 1991 to 1995 meant less meat and more walking. Weight loss averaged 14 pounds, and rates of diabetes and heart disease fell. When the crisis was over, people regained weight and diabetes rates doubled (Franco et al., 2013). No wonder the United States is the world leader in obesity and diabetes, with other nations catching up.

Even diseases that are not caused by overweight will increase because the stigma endured by obese adults leads them to avoid doctors and nurses, to eat more, and to exercise less—impairing health far more than weight alone (Puhl & Heuer, 2010). A culture’s emphasis on an ideal BMI, particularly in women, may encourage unhealthy dieting, eating disorders, and overeating (Shai & Stampfer, 2008).

Stigma may explain surprising sex differences: More U.S. women than men are at a healthy weight (do they care more?) or obese (do they give up if they can’t stay thin?). The 2012 numbers for adults (age 20–64) are as follows: Rates of healthy weight [BMI 18.5–24.9] were 26 percent for men and 33 percent for women, but rates of marked obesity [BMI 35 and above] were 13 percent for men and 18 percent for women.

ACHIEVING A HEALTHY WEIGHT The basics of a healthy diet are similar all over the world. Common in Greece and Italy is the so-called Mediterranean diet, high in fiber, fish, and olive oil. For people no matter what their ancestry, the Mediterranean diet protects against heart disease without adding weight (Estruch et al., 2013). It may benefit cognition as well (Valls-Pedret et al., 2015).

One surprising food has recently been proven to reduce obesity and mortality in all ethnic groups—nuts, either peanuts or tree nuts (Luu et al., 2015). Eating a few nuts a day, plain or as peanut butter, seems protective. Caution and research are always needed, as many diets and foods that are said to reduce or increase weight are eventually proven not to do so.

434

For morbidly obese adults, surgery may be the best option. About 200,000 U.S. residents undergo bariatric surgery each year. The rate of complications is high: About 1 percent die soon after the surgery and about 10 percent need a second operation.

Over time, however, surgery that successfully reduces overeating saves lives because morbid obesity increases the death rate (Adams et al., 2012). The greatest benefits seem to occur for people with diabetes: 70 percent find that their diabetes disappears, usually not to return (Arterburn et al., 2013). Indeed, bariatric surgery over the long term may improve health of the obese even compared to the general population—overweight or not (Telem et al., 2015).

436