How do sex and gender influence wellness?
How do race and ethnicity affect wellness?
How do income level and educational attainment influence wellness?
How does heredity/family history influence wellness?
Why do women live longer than men?

The World Health Organization defines sex as the biological and physiological characteristics that define men and women; these characteristics are related to chromosomes and their effects on reproductive organs and the functioning of the body. Menstruation in women and the presence of testicles in men are examples of sex-related characteristics. Gender is defined as roles, behaviors, activities, and attributes that a given society considers appropriate for men and women. A person's gender is rooted in biology and physiology, but it is shaped by experience and environment—how society responds to individuals based on their sex. Examples of gender-related characteristics that affect wellness include higher rates of smoking and drinking among men and lower earnings among women (compared with men doing similar work).

       Sex and gender affect wellness in many ways. The lists below highlight just a few of the many differences that can affect wellness.

Women

• Women live longer than men (about five years, on average) but have higher rates of disabling health problems like arthritis, osteoporosis, and Alzheimer's disease.
• On average, women are shorter, have a lower proportion of muscle, and tend to have a "pear" body shape, with excess body fat stored in the hips.
• Obesity is more common in women than in men.
• Women score better on tests of verbal fluency, speech production, fine motor skills, and visual and working memory.
• Women experience heart attacks, on average, about 10 years later than men, but they have a poorer 1-year postattack survival rate. Women are more likely to experience atypical heart attack symptoms such as fatigue and difficulty breathing or "silent" heart attacks, which occur without chest pain.
• Women are more likely to have a stroke or to die from a stroke, but women are also more likely to recover language ability after a stroke affecting the left side of the brain.
• Women have lower rates of smoking but have a higher risk of lung cancer at a given level of exposure to cigarette smoke.
• Women become more intoxicated at a given level of alcohol intake.
• Women have stronger immune systems and are less susceptible to infection by certain bacteria and viruses, but they are more likely to develop autoimmune diseases such as lupus.
• Women are more likely to react to stressors with a response called tend-or-befriend that involves social support; this response may give women a longevity advantage by reducing the risk of stress-related disorders.
• Women are more likely to suffer from migraine and chronic tension headaches
• Women are more likely to suffer from depression and to attempt suicide.
• Women are more likely to be infected with a sexually transmitted disease (STD) during a heterosexual encounter, and they are more likely to suffer severe and long-term effects from STDs, including chronic infection and infertility.

Men

• Men have a shorter life expectancy than women, but they have lower rates of disabling health problems.
• On average, men are taller, have a higher proportion of muscle, and tend to have an "apple" body shape, with excess body fat stored in the abdomen.
• Men score better in tests of visual-spatial ability—for example, the ability to imagine the relationships between shapes and objects when rotated in space.
• Men experience heart attacks, on average, about 10 years earlier than women, but they have a better 1-year postattack survival rate. Men are more likely to have classic heart attack symptoms like chest pain.
• Men are less likely to die from a stroke but are more likely to have permanent loss of language ability following a stroke affecting the left side of the brain.
• Men have higher rates of smoking, spit tobacco use, and alcohol use and abuse.
• Men have higher rates of death from causes linked to intoxication, risk-taking behavior, firearms, unintentional injuries (car crashes, drowning), homicide, and suicide.
• Men are more likely to be exposed to toxic or cancer-causing chemicals on the job.
• Men are more likely to react to stressors with an aggressive or hostile response, a pattern that may increase the risk of stress-related disorders.
• Men have lower rates of depression and are less likely to attempt suicide; however, men are much more likely to succeed at suicide, and many more men than women die each year from suicide.
• Men are more likely to suffer from cluster headaches.
• Men are less likely to be infected with an STD during a heterosexual encounter.
• Men are more likely than women to suffer diseases such as alcoholism, ADHD, and Parkinson's disease.

SOURCES: World Health Organization. 2006. Gender and HIV/AIDS (http://www.who.int/gender/hiv_aids/en; retrieved February 12, 2006 ); Entering a new age of gender medicine. 2003. Consumer Reports on Health, December; Institute of Medicine. 2001. Exploring the Biological Contributions to Human Health: Does Sex Matter? Washington, D.C. : National Academy Press.

Many differences among people are insignificant when it comes to wellness, but some of our differences have important implications. Differences among ethnic groups result from a mix of genetic variations, environmental factors, and health behaviors. The federal government collects population and health information on five broad ethnic minority groups in the United States. Each group has some specific health concerns, but it is important to remember that it is often difficult to separate factors related to ethnicity from those associated with socioeconomic status and educational attainment.

* Latinos (about 14.4% of the U.S. population) are a diverse group, with roots in Mexico, Puerto Rico, Cuba, and South and Central America. Many Latinos are of mixed Spanish and American Indian descent or of mixed Spanish, Indian, and African American descent. Latinos on average have lower rates of heart disease, cancer, and suicide than the general population, but higher rates of infant mortality and a higher overall birth rate; other areas of concern include gallbladder disease and obesity. At current rates, about one in two Latinas will develop diabetes in her lifetime. Many more Latinos than whites or African Americans report having no insurance, no usual source of health care, and no health care visits within the past year; and this difference persists even among nonpoor Americans.

* African Americans (about 12.8% of the U.S. population) have the same leading causes of death as the general population, but they have a higher infant mortality rate and lower rates of suicide and osteoporosis. The higher rate of infant mortality is seen even in mothers who are college graduates and have higher incomes. Other areas of special concern for African Americans include high blood pressure, stroke, diabetes, asthma, and obesity. African American men are at significantly higher risk of prostate cancer than men in other groups, and early screening is often recommended for them. On the positive side, African Americans are more likely to report consuming five or more servings of fruits and vegetables per day than people from other ethnic groups.

* Asian Americans (about 4.5% of the U.S. population) include people who trace their ancestry to countries in the Far East, Southeast Asia, or the Indian subcontinent, including Japan, China, Vietnam, Laos, Cambodia, Korea, the Philippines, Indian, and Pakistan. Asian Americans have a lower death rate and a longer life expectancy than the general population. They have lower rates of coronary heart disease and obesity. However, health differences exist among these groups. For example, Southeast Asian men have higher rates of smoking and lung cancer, and Vietnamese American women have higher rates of cervical cancer.

* American Indians and Alaska Natives (about 1.2% of the U.S. population) typically embrace a tribal identity, such as Sioux, Navaho, or Hopi. American Indians and Alaska Natives have lower death rates from heart disease, stroke, and cancer than the general population, but they have higher rates of early death from causes linked to smoking and alcohol use, including injuries and cirrhosis. Diabetes is a special concern for many groups; for example, the Pimas of Arizona have the highest known prevalence of diabetes of any population in the world.

* Native Hawaiian and Other Pacific Islander Americans (about 0.3% of the U.S. population) trace their ancestry to the original peoples of Hawaii, Guam, Samoa, and other Pacific Islands. Pacific Islander Americans have a higher overall death rate than the general population and higher rates of some diseases, including diabetes and asthma. High rates of smoking and high prevalence of overweight and obesity are special concerns for this group.

SOURCES: U.S. Census Bureau, CDC National Center for Health Statistics, Kaiser Family Foundation, U.S. Department of Health and Human Services.

Poverty and low educational attainment are the most important factors underlying health disparities among Americans. People with low incomes and less education have higher rates of death from all causes, especially chronic disease and injury, and they are less likely to have preventive health services such as vaccinations and Pap tests. They are more likely to live in an area with a higher rate of violence, higher levels of pollutants, and many more environmental stressors. They also have higher rates of unhealthy behaviors such as tobacco and alcohol use, poor diet, and inactivity.

       People with low incomes are less likely to have health insurance and more likely to have problems paying for health care and arranging for transportation and time away from family responsibilities in order to access care. They are also more likely to lack information about available services and appropriate lifestyle choices and preventive care.

The amount of influence your genes have on your level wellness varies with different physical attributes and health conditions. Your genome consists of the complete set of genetic material in your cells. It contains about 25,000 genes, half from each of your parents. Genes control the production of proteins that serve both as the structural material for your body and as the regulators of all your body's chemical reactions and metabolic processes. The human genome varies only slightly from person to person, and many of these differences do not affect health. However, some differences have important implications for health, and knowing your family health history can help you determine which conditions may be of special concern for you.

       Variations or errors in our genes are responsible for about 3500 clearly hereditary conditions, including sickle-cell disease, hemophilia, and cystic fibrosis. In these relatively uncommon conditions, heredity is the primary cause; if your parents pass on the necessary genes, you'll get the disease. These conditions are typically due to a small number of genes.

       Genetic variations also play a part in heart disease, cancer, stroke, diabetes, and many other common conditions. However, in these more common and complex disorders, genetic alterations serve only to increase an individual's risk—they do not guarantee that the condition will occur. These common chronic diseases result from the interaction of many genes with other factors. For example, researchers have identified genes that clearly increase a woman's risk for breast cancer, but these genes explain only a small proportion of cases. In the small number of inherited cases, genetic alterations that increase the risk of cancer are present at birth in the genes of all the cells in the body. In the majority of cases, however, cancer results from genetic changes that occur after birth within particular cells—usually in response to environmental and lifestyle factors.

       Another example of the power of behavior and environment can be seen in the more than 60% increase in the incidence of diabetes that has occurred among Americans since 1990. This huge increase is not due to any sudden change in our genes; it is the result of increasing rates of obesity caused by poor dietary choices and lack of activity. A person may carry genes that make body cells resistant to insulin, thereby increasing the risk of diabetes. But these genes only come into play when the individual has excess body fat.

       Putting together a family health history can help you identify conditions that may run in your family—and for which you may carry genes that could potentially increase your risk. Knowing that a specific disease runs in your family can help alert you to screening tests and lifestyle changes that would be especially beneficial for you. For example, if you have a family history of early heart disease and high cholesterol levels, you can reduce your risk by increasing physical activity and paying special attention to diet.

       In general, the more relatives with a disease, and the closer they are to you, the greater your risk. However, nongenetic factors—such as health habits—can also play a role. Signs of strong hereditary influence include early onset of the disease, appearance of the disease largely or exclusively on one side of the family, onset of the same disease at the same age in more than one relative, and developing the disease despite good health habits. For example, having one grandparent who died of heart disease at age 80 is not a strong indicator of increased genetic risk. A stronger indication of genetic risk would be if your father and grandfather, both fit nonsmokers on the same side of the family, had heart attacks in their forties.

       The Surgeon General's family health history website (www.hhs.gov/familyhistory) provides advice on creating and interpreting a family health tree. Your physician and/or a genetic counselor can also help you put together a family health history and then target the health behaviors and screening tests that are most important for you.

       Women live longer than men in most countries around the world, even in places where maternal mortality rates are high. In the United States, women on average can expect to live about five years longer than men. Worldwide, among people over age 100, women outnumber men about 9 to 1.

       The reason for the gender gap in life expectancy is not entirely understood but may be influenced by biological, social, and lifestyle factors. Estrogen production and other factors during a woman's younger years may protect her from early heart disease and from age-related declines in the pumping power of the heart. Women may have lower rates of stress-related illnesses because they cope more positively with stress by seeking social support.

       The news for women is not all good, however, because not all their extra years are likely to be healthy ones. They are more likely than men to suffer from chronic conditions such as arthritis and osteoporosis. Women's longer life spans—combined with the facts that men tend to marry younger women and that widowed men remarry more often than widowed women—mean there are many more single older women than men. Older men are more likely to live in family settings, whereas older women are more likely to live alone. Older women are also less likely to be covered by a pension or to have retirement savings, so they are more likely to be poor.

       Increased male mortality can be traced in part to higher rates of behaviors such as smoking and alcohol and drug abuse. Testosterone production may be partly responsible in that it is linked to aggressive and risky behavior and to unhealthy cholesterol levels. Men have much higher rates of death than women from car crashes and other unintentional injuries, firearm-related deaths, homicide, suicide, AIDS, and early heart attack. Gender roles that promote risky behavior among young men are a factor in many of these causes of death. Indeed, among people who have made it to age 65, the gender longevity gap is smaller.

       Social and behavioral factors may be more important than physiological causes in explaining the gender gap; for example, among the Amish, a religious sect that has strict rules against smoking and drinking, men usually live as long as women. This suggests that the longevity gap could be substantially narrowed through lifestyle changes.

Sources: U.S. Census Bureau, National Center for Health Statistics, World Health Organization.