My parents say that, when they were my age, they had more friends than I do. Is this normal?
How can I tell if my relationship is healthy?
What are some of the pros and cons of online dating?
What are stem cells, and how can they be used in medicine?
Are online pharmacies a good choice?
What is acupuncture?
I see ads for prescription drugs on TV all the time. What are some of the pros and cons of this type of advertising?
Are herbal remedies safe?
Who are the uninsured in America?
What is smog?
What is radon?
How does energy use affect environmental health?

If you have a small circle of friends, you may be part of a trend. The average American's social circle is shrinking—to the extent that many of us have no one to talk to about our problems.

          In 2006, sociologists from Duke University and the University of Arizona released details of a study confirming the problem. The researchers reviewed data from the General Social Survey, culled over a 20-year period. The data focused specifically on relationship issues.

          According to the study, Americans have fewer close friends than ever before. Most Americans have only two friends they consider close enough to discuss problems with. (In 1985, the average American had three confidants.) Nearly 25% of the survey's respondents reported having no one they wanted to confide in.

          Although social networks may be shrinking, we seem to be strengthening our family ties. About 80% of Americans say they talk to family members about their troubles; about 10% have such discussions exclusively with their spouse rather than with friends or family members.

          The study's authors suggest several reasons for this social change, including the aging of society, the ease with which people move to new jobs or cities, and the changing cultural mix of towns and neighborhoods.

          Whatever the explanation, social scientists agree that the decline in interpersonal networks could be problematic for society. For many reasons, they say, it's better to have friends with whom we can share joy, problems, secrets, and interests. Strong friendships, and the open communication they encourage, promote both physical and emotional wellness.

SOURCE: McPherson, M., L. Smith-Lovin, and M. Brashears. 2006. Social isolation in America: Changes in core discussion networks over two decades. American Sociological Review 71: 353-375.

Relatively extreme examples of unhealthy relationships are those that are physically or emotionally abusive or that involve codependency; these are usually not too difficult to recognize if one is honest with oneself. But other relationships, while not abusive or codependent, may still be unhealthy. Psychologist and relationship expert John Gottman suggests that if your relationship lacks love and respect and places little value on the time you have spent together, it may be time to get professional help or to end the partnership. Further, if your relationship is characterized by communication styles that include criticism, contempt, defensiveness, and withdrawal—despite real efforts to repair these destructive patterns—the relationship may not be salvageable. Some other questions to consider: Do you and your partner have more negative experiences and interactions than positive ones? Are there old hurts that you or your partner cannot forgive? Do you feel disrespected or unloved? Do you find it hard to feel positive feelings of affection for your partner? Does it feel like your relationship has been a waste of time? Spiritual leaders suggest that relationships are unhealthy when you feel that your sense of spontaneity, your potential for inner growth and joy, and your connection to your spiritual life is deadened. There are negative physical and mental consequences of being in an unhappy relationship; and although breaking up is painful and difficult, it is ultimately better than living in a toxic relationship.

More and more people today are looking to the World Wide Web to find friends and partners, and about 16 million singles have tried online dating. Communicating with others in cyberspace allows people to be themselves in a relaxed atmosphere, to try out other personas, and to confide in others in a private and less vulnerable way. The Internet can also serve as "training wheels" for those who wish to develop their social skills. For those out of college, living in big cities, not interested in "bar scenes," and/or looking to expand beyond their local network of friends, the Internet provides a rich resource for making connections. Many find that there is a sense of safety and comfort, along with efficiency, associated with online dating. It is easy to put yourself "out there" without too much investment—you can get to know someone from the comfort of your own home, the pace is up to you, and you can end the relationship at any time. With millions of singles using dating forums that allow them to outline exactly what they are seeking, the Internet can increase a person's chance of finding a good match.

          There are drawbacks to meeting partners online, however. People can misrepresent themselves, pretending to be very different—older or younger or even of a different sex—than they really are. Investing time and emotional resources in such relationships can be painful. There have also been a few instances in which online romances have become dangerous or even deadly.

          Because people have greater freedom to reveal only the best parts of themselves, users should also be aware of a greater tendency to idealize online partners—setting themselves up for later disappointment. If you find that your online friend seems more perfect than anyone you have ever met in person, consider that a warning sign. Looking for partners online can become like "shopping"—the choices available to you may increase your tendency to search for perfection or find fault quickly, thereby keeping you from giving people a chance. Remember what is most important to you and keep your expectations realistic.

          When looking for friends or partners online, you also are reducing an important and powerful source of information: chemistry and in-person intuition. Much of our communication is transmitted through body language and tone, which are not available online and cannot be fully captured even by Web cams. You will therefore need to trust your feelings regarding the process of the relationship. Are you revealing more than the other person? Is there a balance in the amount of time spent talking by each of you? Is the other person respecting your boundaries? Just as in real-life dating, online relationships require you to use common sense and to trust your instincts.

          If you decide to pursue an online relationship, here are some strategies that can help you maximize your experience and keep you safe:

• To increase your chances of meeting people interested in you as a person, avoid sexually orientated Web sites.
• Know what you are looking for as well as what you have to offer someone else. If you are looking for a relationship, make that fact clear. Find out the other person's situation and intentions (recently out of a long-term relationship or marriage, looking for a serious relationship or just for a distraction, etc.).
• If you answer an ad, let the person know what you found interesting about the post. If you write an ad of your own, include something unique that represents some of your interests and personality. Read others' ads to become inspired, have a friend help you write yours, and/or visit the Web site's guide for creating ads. An ad doesn't have to be "perfect" or represent all of you.
• Many Web sites have a place to put a photo and, if you are serious about the pursuit of a partner, you may find that you get many more responses when you post a photo. Know, however, that your photo can then be downloaded by anyone. If this does not feel comfortable, remember that it isn't necessary and that you can always choose to add one later.
• Until you know enough about a cyberfriend, don't give out personal information, including your real full name, school, or place of employment. Consider setting up a second e-mail account for sending and receiving dating-related e-mails.
• Take the relationship at a pace that feels comfortable for you, and don't feel you need to answer every e-mail the day you receive it. Reveal personal information only as it feels right for you.
• If someone does not answer your e-mail or show up for an appointment, try not to take it personally. There are many reasons why a person may not pursue the connection.
• Before deciding whether to meet an online friend in person, schedule a phone conversation or a series of phone conversations.
• Don't agree to meet someone face to face unless you feel completely comfortable about it. Always meet initially in a very public place—a museum, a coffee shop, or a restaurant. Bring along a friend to further increase your safety, or let a friend know where you will be.

          Finally, take care that your pursuit of online relationships does not interfere with your other interpersonal relationships and social activities. There can be an addictive element to online dating that can become unhealthy. Don't use the Internet to escape from real-life problems or important personal issues, such as healing from the loss of a prior relationship. Extensive use of the Internet is associated with greater loneliness, less communication with family members, and fewer social contacts. It is easy not to speak to "real" people all day and then retreat to your comfort zone and connect in cyberspace. Don't forget to stay interactive in the real world. To maximize your emotional and interpersonal wellness, use the Internet to widen your circle of friends, not shrink it.

Nearly all the cells in our body are differentiated, meaning they are committed to specific functions. We have heart cells, skin cells, nerve cells—more than 260 kinds in all. Stem cells, on the other hand, are undifferentiated; they can renew themselves by continuing to divide in their undifferentiated state for long periods, or they can develop into specialized cells as needed. The ability to develop into almost any type of tissue gives stem cells great therapeutic potential.

          Theoretically, stem cells can be used to create replacement cells for many diseased or injured tissues. For example, if scientists can coax stem cells into differentiating, they may be able to create insulin-producing cells to treat diabetes, cardiac muscle cells to repair a damaged heart, or healthy brain cells for people with Parkinson's disease. Experts hope that stem cells can be widely produced and matched to a patient's cellular make-up. But before this can happen, technical and ethical problems must be solved.

          As their name suggests, embryonic stem cells are derived from embryos. About 4-5 days after fertilization, an embryo is a microscopic ball of cells, called a blastocyst. At this stage, the embryo contains about 30 stem cells; scientists can remove these cells and grow them, producing millions of embryonic stem cells. This method kills the embryo, however, and gives rise to the ethical debate that swirls around stem cell research. Most embryonic stem cells used in research are derived from eggs that have been fertilized in vitro, then donated to research; they are not taken from embryos fertilized in the womb.

          In mid-2006, a team of researchers announced that a single stem cell (called a blastomere) could be taken from a 2- or 3-day-old embryo without destroying the embryo. So soon after fertilization, the embryo contains only 8 cells. This technique, in fact, is sometimes performed on embryos created through in vitro fertilization. Scientists allow the blastomere to multiply, then test the cells for defects before implanting the embryo—which has continued developing from the 7 remaining cells—in the mother's womb. Fertilization experts report that such embryos develop into healthy babies.

          Some organs and tissues in the adult body can replace cells, while others do not seem to have this ability. Researchers now believe that cellular repair is carried out by stem cells that lie dormant in tissues until they are needed. Adult stem cells, therefore, are harder to work with than embryonic stem cells because they are rare, tougher to locate, and more difficult to reproduce.

          Adult stem cells seem to have some plasticity, or the ability to differentiate. For example, hematopoietic stem cells in bone marrow can turn into all the different types of blood cells. But there is only limited evidence to suggest that adult stem cells from one tissue can turn into functional cells of another type of tissue.

          The hematopoietic stem cell is the most studied type of adult stem cell and the only one widely used in clinical applications. These cells are used in transplants to restore blood and immune components to the bone marrow of people being treated for cancer and other diseases. Hematopoietic stem cells for transplant can be collected from a donor, but they are also sometimes derived from umbilical cord blood.

          Although transplant success rates have improved, rejection remains a major problem, and success depends on finding a close cellular match between donor and recipient. Another avenue of stem cell research—and a possible solution to rejection—is somatic cell nuclear transfer. In this technique, the nucleus from a somatic (body) cell is placed in an egg whose nucleus has been removed. The egg is allowed to grow into a blastocyst, then the resulting stem cells are removed. This process, also called therapeutic cloning, produces a line of stem cells that are genetically matched to the original cell's donor; using these stem cells for transplant should eliminate problems with rejection. (This technique is distinct from reproductive cloning, in which an embryo is created through somatic cell transfer, then implanted into a woman's uterus and allowed to develop. This process results in an offspring who is genetically identical to the donor of the original somatic cell.)

          Many experts believe that research into both embryonic and adult stem cells is needed to advance the therapeutic potential of stem cell research. However, the use of human embryos for such research is controversial. Some people advocate a complete ban; others would permit the use of existing stem cell lines, the use of extra embryos produced through in vitro fertilization, or the use of embryos created from eggs and sperm donated specifically for research.

          In 2001, President Bush banned the use of federal funds for any research related to the creation of new embryonic stem cell lines, thus limiting research to a small number of existing lines. Researchers believe that there are problems with this restriction, highlighted by the announcement in 2005 that all existing stem cell lines may be contaminated with compounds used in the storage process. Some private institutions in the United States and abroad now provide funds for the creation of new embryonic stem cell lines.

          In July, 2006, the Senate approved legislation to expand federal funding for embryonic stem cell research. President Bush vetoed the bill—his first use of presidential veto power. In response, two governors approved state funds for such research, adding to an already confusing patchwork of state laws regarding stem cells. Meanwhile, Taiwan and several European countries have jumped into the stem cell arena, providing funding for research and approving laws supporting stem cell use. As a result, many prominent American researchers have gone abroad in hopes of continuing their work under more favorable circumstances.

          Despite the problems and unknowns, researchers are optimistic. Results from early tests of adult stem cells used to treat heart failure have been promising. Trials of treatments for other conditions have begun, as well.

Although convenient, some online pharmacies may sell products or engage in practices that are illegal in the offline world, putting consumers at risk for receiving adulterated, expired, or counterfeit drugs. The FDA recommends that consumers avoid sites that prescribe drugs for the first time without a physical exam, sell prescription drugs without a prescription, or sell drugs not approved by the FDA. You should also avoid sites that do not provide access to a registered pharmacist to answer questions or that do not provide a U.S. address and phone number to contact if there's a problem. (There have been cases of online pharmacies claiming they are operating out of the United States or Canada but which were in fact located in another country where there is little or no regulation.) The National Association of Boards of Pharmacy sponsors a voluntary certification program for Internet pharmacies. To be certified, a pharmacy must have a state license and allow regular inspections. Many experts recommend that consumers use online pharmacies only to obtain medicine prescribed by their usual health care provider.

Acupuncture is a technique used in traditional Chinese medicine (TCM). In TCM the free and harmonious flow of qi produces health—a positive feeling of well-being and vitality in body, mind, and spirit. Illness occurs when the flow of qi is blocked or disturbed. Acupuncture works to correct disturbances in the flow of qi through the insertion of long, thin needles at appropriate points in the skin. Qi is believed to flow through the body along several meridians, or pathways, and there are approximately 360 acupuncture points located along these meridians. Acupuncturists use a variety of diagnostic techniques to identify the nature of the imbalance in a patient and to choose the points at which acupuncture needs to be applied. The traditional method consists of inserting a needle and then manipulating in manually, but other means of manipulation, such as heat, pressure, suction, or electric stimulation, can also be used.

          Western researchers typically use a different framework for understanding the effects of acupuncture. For example, they might explain pain relief not in terms of qi but in terms of stimulation of the nervous system and release of hormones and neurotransmitters. Research into the effectiveness of acupuncture is ongoing; studies have supported its effectiveness in relieving nausea after chemotherapy and pain after surgery, including dental surgery. In the United States, the FDA regulates acupuncture needles like other standard medical devices and requires that they be sterile. Most acupuncture practitioners follow these regulations, but, if you consider acupuncture, you should ask your practitioner about the relative risks of the procedure and the safety practices he or she observes. A majority of states require some form of licensing or credentialing for practitioners of acupuncture.

The pharmaceutical industry spends up to 20% of its marketing budget on direct-to-consumer (DTC) advertising, which has grown rapidly since 1995. Most of these ads are for a small number of the most popular drugs. Proponents of DTC advertising claim that it enhances public health by providing educational information about underdiagnosed conditions such as diabetes, high cholesterol, and depression and by motivating people to seek care. DTC advertising may be particularly useful in getting health information to people who have no regular source of health care. It may also provide patients with an opportunity to discuss medical conditions that they might otherwise be hesitant to bring up, such as depression.

          Opponents claim that DTC advertising is more promotional than educational, is misleading and omits important precautions, is designed to create consumer demand by creating problems and needs, and causes patients to pressure physicians to prescribe particular drugs. One recent study found that most DTC ads fail to provide information about how a drug works, its success rate, how long it must be taken, alternative treatments, or helpful lifestyle changes. There is also concern that DTC advertising leads patients to request heavily advertised drugs when older, less expensive medications may be equally effective. Many people equate "newer" with "better" and "safer," but that is not always the case.

Consider the following research findings and FDA advisories:

• St. John's wort interacts with drugs used to treat HIV infection and heart disease; the herb may also reduce the effectiveness of oral contraceptives, antirejection drugs used with organ transplants, and some medications used to treat infections, depression, asthma, and seizure disorders.
• Chinese herbs contaminated through a manufacturing error with the powerful carcinogen aristolochic acid caused kidney damage and bladder cancer in patients at a weight-loss clinic in Belgium.
• Supplements containing kava have been linked to severe liver damage, and anyone who has liver problems or takes medications that can affect the liver are advised to consult a physician before using kava-containing supplements.
• In a sample of ayurvedic herbal medicine products, 20% were found to contain potentially harmful levels of lead, mercury, and/or arsenic.

These findings highlight growing safety concerns about dietary supplements, which now represent annual sales of more than $15 billion in the United States.

          As in the case of St. John's wort, the chemicals in botanicals (products derived from plants) can interact dangerously with prescription and over-the-counter drugs. Botanicals may decrease the effects of drugs, making them ineffective, or increase their effects, in some cases making them toxic. Alarmingly, most patients fail to tell their physicians about their use of herbal substances. Botanicals can also interact with alcohol, usually heightening its effects.

          There are also complex interactions among the constituents of a single herbal preparation. And many manufacturers are offering new combinations of botanical preparations without empirical or scientific information about the interactions of the individual ingredients.

          A related problem is the lack of standardization in the manufacturing of herbal products. The Dietary Supplement Health and Education Act of 1994 requires that dietary supplement labels list the name and quantity of each ingredient. However, confusion can result because different plant species—with distinct chemical compositions and effects—may have the same common name. The content of herbal preparations is also variable. A 2003 study of Echinacea supplements found that only about half contained the species and amount listed on the label; 10% of the samples contained no Echinacea at all. Part of the reason for such variation is the difficulty of identifying the active ingredients in botanicals and isolating and standardizing their concentrations. The chemical composition of a supplement is also affected by the growing, harvesting, processing, and storage conditions of plants.

          A variety of traditional Chinese and ayervedic remedies contain heavy metals such as lead, mercury, and arsenic as part of their formula, all of which can be highly toxic and can cause irreversible damage. Some Chinese herbal remedies have been found to contain pharmaceutical drugs, including tranquilizers and steroids. Others contain herbs not listed on the label; sometimes substitute herbs that have toxic effects. Many plants are poisonous or can cause damage to the liver or kidneys if taken over long periods of time. Experts have also advised against taking supplements that contain raw animal parts, particularly central nervous system tissue, out of concern that disease may be transmissible this way. People with certain health conditions should be cautious when using herbal remedies. These conditions include Parkinson's disease, diabetes, epilepsy, hypertension, and psychiatric conditions.

          Some European governments assume greater responsibility in regulating botanical products than the U.S. government does. In Germany, manufacturing is standardized so that content, quantity, quality, and purity are guaranteed. Botanicals do not have to be proven effective to be marketed, but they do have to be proven safe.

          In the United States, because herbs are considered supplements rather than food or drug products, they do not have to meet FDA food and drug standards for safety or effectiveness, nor do they currently have to meet any manufacturing standards. The manufacturer is responsible for ensuring that a supplement is safe before it is marketed; the FDA has the power to restrict a substance if it is found to pose a health risk after it is on the market. Because U.S. manufacturers can put almost anything into an herbal supplement,

          American consumers are at risk of buying and using products that may not be just useless but harmful as well. Part of the reasoning behind this situation is that herbal products are considered safer than conventional medicines.

Despite high national levels of spending on health care, many Americans under age 65—almost 17% or nearly 1 in 5—do not have health insurance. (Americans age 65 and over are often covered by government programs.) This overall statistic about the uninsured hides some important differences among groups.

• Income. The factor most closely associated with lack of health insurance is low income. People who are at 200% or more of the federal poverty level are significantly more likely to be insured than those in low-income brackets.
• Age. Young adults are less likely to be insured than older adults. Younger adults may not be regularly employed and so may not be covered by an insurance plan through work.
•  Ethnicity. Ethnic minorities are less likely to be insured than whites. Latinos, especially persons of Mexican origin, have the lowest rates of insurance coverage. Much of the ethnic variations are explained by socioeconomic status. However, other factors may also contribute, including language barriers, differing cultural attitudes toward medical care, and living the medically underserved communities.

          People without health insurance receive less health care and lower quality of care. They have fewer physician visits and less preventive care. To help overcome the health gap between ethnic minorities and the general population, the U.S. Department of Health and Human Services sponsors "Take a Loved One for a Checkup Day." Held on the third Tuesday in September, this event is designed to encourage people to obtain preventive care. People are encouraged to make an appointment for themselves or for a friend or family member who hasn't seen a health care provider recently.

          People who don't have a regular health care provider or who don't have health insurance can contact a local health department or local community center to find out more about free or low-cost care.

Sources: National Center for Health Statistics. 2006. Health, United States, 2006. Hyattsville, Md.: U.S. Public Health Service; U.S. Department of Health and Human Services, Office of Minority Health Resource Center. 2006. Fact Sheet: Take a Loved One for a Checkup Day (http://www.omhrc.gov/healthgap/2206drday.aspx).

The term smog was first used in the early 1900s in London to describe the combination of smoke and fog. What we typically call smog today is a mixture of pollutants, with ground-level ozone being the key ingredient. Major smog occurrences are linked to a combination of several factors: Heavy motor vehicle traffic, high temperatures, and sunny weather can increase the production of ozone. If such conditions persist for several days, the buildup of pollutants may reach dangerous levels and threaten people's health. Pollutants are also more likely to build up in areas with little wind and/or where a topographic feature such as a mountain range or valley prevents the wind from pushing out stagnant air.

Radon is a naturally occurring radioactive gas found in certain soils, rocks, and building materials. When the breakdown products of radon are inhaled, they cling to lungs and bombard sensitive tissue with radioactivity. Among miners, exposure to high levels of radon has been shown to cause lung cancer. Radon can enter a home by rising through the soil into the basement through dirt floors, cracks, and other openings.

          In 2005, the Surgeon General issued a national health advisory on radon, recommending that Americans test their homes for radon every two years, and retest any time they move, make structural changes to a home or occupy a previously unused level of a residence. If elevated levels are found (4 pCi/L or more), the problem should be dealt with as soon as possible through such measures as sealing cracks or installing basement ventilation systems. More information is available at the EPA Web site or by calling 1-800-SOS-RADON.

How does energy use affect environmental health?

Americans are the biggest energy consumers in the world.

Source: Energy Information Administration

About 85% of the energy we use comes from fossil fuels—oil, coal, and natural gas. The remainder comes from nuclear power and renewable energy sources (such as hydroelectric, wind, and solar power). Energy consumption is at the root of many environmental problems, especially those relating to air pollution. Automobile exhaust and the burning of oil and coal by industry and by electric power plants are primary causes of smog, acid precipitation, and the greenhouse effect. The mining of coal and the extraction and transportation of oil cause pollution on land and in water; coal miners often suffer from serious health problems related to their jobs. Nuclear power generation creates hazardous wastes and carries the risk of dangerous releases of radiation.

          Two key strategies for controlling energy use are conservation and the development of nonpolluting, renewable sources of energy. Although the use of renewable energy sources has increased in recent years, renewables still supply only a small proportion of our energy, in part because of their costs. Some countries have chosen to promote energy efficiency by removing subsidies or adding taxes on the use of fossil fuels. This strategy is reflected in the varying prices drivers pay for gasoline. Although U.S. gas prices are higher than in the past, they are still several dollars a gallon lower than in many European and Asian countries. It is not surprising that per-capita energy use in the United States is twice that of many European countries. The International Center for Technology Assessment estimates that the actual price of gasoline—including tax breaks, government subsidies, and environmental, health, and social costs of gas usage—is above $15 per gallon.

          Despite recent increases in U.S. consumer gas prices, more than 70% of commuters drive alone to work, and low-fuel-economy sport utility vehicles (SUVs) remain popular. Every gallon of gas burned puts about 20 pounds of carbon dioxide into the atmosphere; some SUVs average fewer than 10 miles per gallon, and the largest SUVs increase greenhouse gas emissions by six tons or more per year more than an average car. A more positive U.S. trend has been the introduction of hybrid electric vehicles (HEVs), which combine a conventional internal combustion engine with an electric motor, resulting in about twice the fuel economy of conventional vehicles. Researchers hope that hybrid technology can be extended to all classes of vehicles and that Americans can be convinced to use more fuel-efficient vehicles and to travel more frequently on public transportation, in carpools, or on foot.