Year in Medicine A-Z
December 04, 2005
Sora Song, Alice Park, Coco Masters, Time Magazine
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ACUPUNCTURE There is growing scientific evidence that acupuncture, a pillar of Chinese medicine, can relieve many kinds of pain, but there's no clear agreement about how it works. That was underscored by a German study of migraines: it found that inserting needles at various acupuncture points in the body relieved pain just as effectively as inserting them in the points that are supposed to affect migraines.
AIDS This was the year that the World Health Organization (WHO), under the banner of its innovative "3 by 5" campaign, was supposed to put 3 million AIDS patients in the developing world on life-saving antiretroviral drugs. With only a month left in 2005, the WHO is expected to fall short of its goal, but most experts still consider the plan a success. Fourteen of the countries hardest hit by the epidemic now provide therapies to at least half their patients who need them. Such aggressive treatment programs are critical as the AIDS virus continues to spread and mutate. The WHO and U.N. last week reported that an estimated 40 million people are HIV-positive, including a record 1 million in the U.S. In New York City, doctors were alarmed to discover a particularly powerful strain of HIV in a sexually active gay man. Resistant to all but one of the classes of anti-AIDS drugs, that fast-working virus appears to lead to full-blown AIDS in a matter of months.
AIR BAGS The National Highway Traffic Safety Administration's boast that inflatable air bags have saved nearly 14,000 lives since 1998, when they were required in all new cars, was challenged by a University of Georgia statistician. By analyzing a random sample of all accidents (rather than just those in which a death occurred), she found that air bags were actually associated with a slightly higher chance of death in an accident. Some of that discrepancy may be attributed to the greater risk of air-bag injuries to children who ride--against all advice--in the front seat of a car.
ALZHEIMER'S One of the most tragic features of this neurological disease is the way patients slip away, slowly losing memory and other brain functions over a span of years. Now there is evidence that the long goodbye of Alzheimer's may begin even earlier than doctors suspected. A Swedish analysis of nearly 50 studies of the condition found that patients who go on to develop Alzheimer's show telltale signs--lapses in memory, reasoning, problem-solving ability, verbal fluency and attention skills--years before the disease is diagnosed. Such symptoms could serve as warning signals, say experts, but doctors need better screening tools to distinguish those changes from the decline in brain function that occurs naturally with age. Meanwhile, University of Southern California researchers found that inflammation caused by lost or loose teeth, and the resulting infection, can quadruple the risk of developing Alzheimer's. Treating those inflammatory episodes could help stave off the disease.
ASPIRIN It turns out the studies that have proved, again and again, that low doses of aspirin taken daily can reduce the risk of a first heart attack--by an average of 30%--were conducted primarily on men. When the effects of aspirin were tested on the 40,000 participants in the giant Women's Health Study, the results were strikingly different: women who took aspirin every other day for 10 years had roughly the same number of heart attacks as those taking a placebo. The only group of women who had fewer heart incidents were those who were at least 65 years old at the start of the trial. The gender gap could have something to do with the fact that women seem to be protected from heart disease by estrogen until menopause and tend to have heart attacks later than men do. (Low-dose aspirin did reduce the risk of stroke in women of all ages.)
ASTHMA A good joke can be as dangerous as dust or pollen for asthma sufferers. In a new study conducted at New York University, more than 50% of asthma patients reported having an asthma attack after laughing too hard. Flour also emerged as an asthma risk factor. British researchers studying supermarket bakeries found that roughly 15% of the workers developed work-related asthma symptoms, including sneezing, wheezing and difficulty breathing.
AUTISM The idea that childhood vaccinations might lead to autism has gained currency among some concerned parents, fueled by unsubstantiated reports on the Internet. The Mayo Clinic decided to test the idea by focusing on a specific population in Minnesota and analyzing the rise in autism cases there since 1988. They found that the apparent increase could be traced to improved awareness of the disease and changes in the way the condition is diagnosed but not necessarily to immunizations. The results will probably not end the debate, but most scientists are convinced that the shots are safe.
AVIAN FLU The possibility of a flu pandemic dominated the news for much of the fall, although the death toll from the virus that has health officials most worried--the so-called H5N1 strain--remains vastly greater in birds than humans. So far, 132 people in Southeast Asia and China are known to have been infected, and more than half of them have died. Meanwhile, millions of chickens and ducks have been slaughtered in a last-ditch attempt to keep the virus from spreading--an effort made more difficult by migrating flocks of wild birds that have carried the virus into Eastern Europe. The only reason more humans haven't died, say experts, is that this particular flu virus still has difficulty transmitting from one person to another. But the fear is that it, or a virus like it, will mutate into a form that spreads as easily as the 1918 flu that killed 20 million (and was caused, it turns out, by an avian-flu virus). It was to prevent such an outbreak that President George W. Bush proposed spending $7.1 billion on flu-pandemic preparedness, including investments in new technologies for developing vaccines and antiviral drugs, as well as shoring up health-care facilities to meet the surge in demand that a flu pandemic would create.
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BIDIL It was the first drug approved by the Food and Drug Administration that comes with a race-specific label: FOR AFRICAN AMERICANS ONLY. When researchers first tested BiDil as a treatment for congestive heart failure, its makers found it had little benefit over a placebo. But in a subset of subjects, who were of African-American descent, the drug, taken along with other medications, reduced deaths from the condition 43% and lowered the number of hospital admissions almost 40%. Researchers say it won't be the last ethnically driven drug on pharmacy shelves; as the genetic basis of diseases becomes clearer, more therapies based at least in part on race-dependent gene variants will appear.
BLACK-BOX WARNINGS For a pharmaceutical, it's the equivalent of a SWIM AT YOUR OWN RISK sign, and this year the Food and Drug Administration issued a couple of big ones. One was for Strattera, a commonly prescribed treatment for attention-deficit/hyperactivity disorder. It earned a boxed warning after reports linking the drug to suicidal thoughts in children and teenagers. The other drug to earn an alert was the popular painkiller Celebrex, part of the class of so-called COX-2 inhibitors that came under scrutiny last year for their heart-related side effects. Its label now warns doctors and patients of the risk of heart attack and stroke. Expect to see more of those warnings as drugs become more sophisticated and start to target the basic biological mechanisms behind disease.
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CANCER Thanks to early detection and better prevention programs, deaths from cancer continue their downward trend. Some highlights:
Breast Cancer When the authors of a large international study reported that Herceptin, a powerful drug for treating advanced cases of so-called HER2-positive breast cancers, could also dramatically reduce--by 46%--recurrence of early-stage HER2 cancers, they triggered impassioned requests for the drug by patients and fierce debate among doctors. At issue was whether the trial, which had reported interim--not final--results, was reliable enough to persuade doctors to change their treatment practices. Most physicians have decided to wait for the trial to be completed in 2008 before making any decisions.
Colon Cancer Keeping colon cancer away may be as simple as taking a calcium supplement. One study reported that patients taking 1,200 mg of the mineral daily for four years had 36% fewer colon polyps, even five years after the trial ended, than those who didn't take calcium. In a separate study, women taking more than 800 mg of calcium every day reduced their risk of colorectal cancer as much as 46%.
Prostate Cancer The sun may be bad for your skin, but it could do wonders for the prostate. A new study found that men with high exposure to the sun had half the risk of prostate cancer than men who spent most of their days indoors. Why? The prostate uses vitamin D--which the body makes in response to sunlight--to help prostate cells grow normally and crowd out cancer cells in the organ.
CLONING Scientists had cloned sheep, pigs, cattle, mice, rabbits, horses and cats but, until this year, never a dog. Man's best friend, it turns out, is extremely difficult to duplicate. It was Woo Suk Hwang and his team at Seoul National University who finally succeeded in turning a single cell from the ear of an Afghan hound into a genetically identical puppy. Hwang was back in the news last week when he admitted lying about the source of some of the human eggs used in an earlier stem-cell experiment. Nevertheless, many scientists suspect the techniques Hwang perfected to clone a dog could be adapted to duplicate almost any species--including a primate.
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DIABETES The number of cases is rising sharply. Nearly 21 million Americans have diabetes (mostly Type 2), and 41 million are prediabetic. Moreover, the situation is deteriorating; the Yale Schools of Public Health and Medicine predicted that the number of deaths due to diabetes each year in the U.S. could triple, to 622,000, by 2025. One way to reduce the risk, according to a 12-year study of milk-drinking men, is to switch to low- or nonfat dairy products. Another is to stay below a body mass index of 30; exceeding that number can almost double a man's chances of developing diabetes, according to the American Journal of Clinical Nutrition. Meanwhile, the FDA approved the smallest diabetes testing system available, Sidekick, to join the list of recently developed tools for diabetics, including blood-sugar monitors with less painful laser lancets and nasal sprays and inhalers for delivering insulin.
DOWN SYNDROME The number of Down syndrome babies born in the U.S. has fallen dramatically since second-trimester screening became routine about 15 years ago--a development viewed with some alarm by both anti-abortion and Down syndrome support groups. Now a new, more accurate screening test could accelerate that trend. Conducted as early as the 11th week of pregnancy, the test gives women more time either to prepare to raise a Down baby or to consider a less-risky first-trimester abortion. The test--which factors in the mother's age, a fetal ultrasound measurement and the levels of two pregnancy-related hormones--is about 87% accurate. An integrated test that combines results from first- and second-trimester screens is 96% accurate.
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EPISIOTOMY Doctors routinely make a small incision, called an episiotomy, to relieve some of the strain on mother and child during a vaginal delivery. The cut is supposed to speed the baby's exit, but cases of fetal distress that would require it are rare. In fact, the operation often does more harm than good. Analyzing 26 studies on the procedure conducted since 1950, researchers found that women who have episiotomies are at greater risk of injury, take longer to heal and don't have a better sex life.
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FISH OIL The good news about omega-3s--the fatty acids in oily fish, such as salmon, sardines and mackerel--continued to accumulate. One report suggested that 2 g of fish-oil supplements taken every day could help protect against heart attacks in the elderly and improve overall heart health in the rest of us in as little as three weeks. But there was bad news too. Another study found that heart patients with implantable defibrillators risk increased heart-rhythm abnormalities if they take too much omega-3.
FOOD PYRAMID The USDA's old food pyramid--with its diminishing stacks of carbohydrates, fruits, vegetables, protein, sweets and fats--may have been a license to overeat, as one expert called it, but at least it was comprehensible. The new pyramid, unveiled in April after long consultation with the food industry, is neither clear nor a call for moderation. To find out what those vertical color bars mean--and to build a customized food plan to fit your age, sex and level of physical activity--you have to visit the website mypyramid.gov
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HEART There's more to a broken heart than a songwriter's cliché. Stress cardiomyopathy, sometimes known as the "broken heart syndrome," is associated with the loss of a loved one and often mistaken for a classic heart attack. But researchers at Johns Hopkins studying a group of mostly female patients discovered that the syndrome is caused by a surge of adrenaline and other stress hormones that temporarily stuns the heart muscle. There is no permanent damage to the heart, however, and patients usually show dramatic improvement in a few days and complete recovery within two weeks.
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LAUGHTER Remember the last time you laughed so hard you couldn't stop? Good. Do it again. Laughter increases blood flow by causing the inner lining of blood vessels (the endothelium) to expand, according to a small study of healthy moviegoers who were shown both funny and distressing clips from films and then tested for the physical effects of each. With laughter, blood flow increased 22%; under stress, it decreased 35%.
LONGEVITY Why do some people live longer than others? One clue comes from a 15-year study of three Greek villages with a combined population of about 1,100. Although those who lived more than 3,000 ft. above sea level had more cardiovascular risk factors--such as higher blood pressure and blood-fat levels--they had lower death rates and fewer deaths from heart disease than their lowland counterparts. Researchers theorize that mountain dwellers may be strengthened by a lifetime of arduous hiking and better adapted physiologically to cope over the long term with high-altitude oxygen levels and other cardiovascular stresses.
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MARIJUANA Research into the analgesic and anti-inflammatory effects of cannabis continued to bolster the case for the medicinal use of marijuana, making the "patient pot laws" that have passed in 11 states seem less like a social movement than a legitimate medical trend. One trial--the first controlled study of its kind--showed that a medicine containing cannabis extracts called Sativex not only lessened the pain of rheumatoid arthritis but actually suppressed the disease. An earlier study published in the Journal of Neuroscience showed that synthetic cannabinoids, the chemicals in marijuana, can reduce inflammation in the brain and may protect it from the cognitive decline associated with Alzheimer's disease.
MALARIA It was a big year for progress against the anopheles mosquito and the malaria parasite it carries. Eradicated in North America with the development of a vaccine 50 years ago, the disease continues to plague the developing world, killing an estimated 1 million people a year, mostly in sub-Saharan Africa. But there were several promising developments in 2005, including a huge influx of research money from the Bill & Melinda Gates Foundation and a pilot project to contain the disease in one African country (see "Zambia"). The best news may be the results of a study of the experimental vaccine developed by GlaxoSmithKline called RTS,S. In a test conducted in Mozambique and funded in part by GSK and the Gateses' Malaria Vaccine Initiative, RTS,S offered the first significant vaccine protection against malaria. The number of clinical cases in a group of children ages 1 to 4 who received the three-dose regimen fell 35%, compared with a control group, while the number of severe cases fell nearly 50%.
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OBESITY The obesity epidemic and its attendant health risks continued to spread around the world. The World Health Organization (WHO) estimated that the number of adults who are overweight or obese passed the 1 billion mark in 2005. Although obesity rates have grown threefold or more since 1980 in some parts of the U.S., Britain, Eastern Europe, the Middle East and the Western Pacific Islands, some of the most rapid increases are found in developing countries. The cause is the same everywhere: increased consumption of energy-dense, nutrient-poor food high in saturated fats and sugar, combined with a decrease in physical exercise. The rise in childhood obesity is especially troubling. The WHO estimated that 22 million children are overweight worldwide, including places like Thailand, where rates of obesity in children ages 5 to 12 rose from 12.2% to 15.6% in the space of two years. Meanwhile, a large U.S. study of the long-term risks of developing obesity suggested that there is more bad news to come. The 30-year study tracked 4,000 white Americans and found that 9 out of 10 men and 7 out of 10 women were overweight or became overweight. In addition, more than 1 out of 3 was obese or became obese. There was some good news: a drug called rimonabant showed promise when used in combination with a restricted-calorie diet. But it's going to take more than a pill or a diet plan to reverse the long-term trends.
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PAINKILLERS Although Ibuprofen and the other over-the-counter painkillers known to doctors as nonsteroidal inflammatory drugs (NSAIDs) do not carry the same risks as the COX-2 inhibitors (see "Black Box Warnings"), they are not problem-free. Reacting to reports of cardiovascular, gastrointestinal and skin problems associated with NSAIDs, the Food and Drug Administration asked manufacturers to rewrite their warning labels.
PARKINSON'S Most people think of Parkinson's disease as something that leads to a shuffling gait or uncontrollable tremors in the hand. But the neurodegenerative process behind the condition can also trigger anxiety or other psychological disorders and--as scientists learned this year--so can the treatment. A Mayo Clinic study found that in rare cases, treatment with a so-called dopamine agonist led 11 patients to develop compulsive-gambling habits (two reported losses over $60,000). Four had never gambled before, but all the patients stopped their wagering within months after treatment was discontinued. The effect was apparently greatest with the drug pramipexole, which investigators theorize indirectly triggered the "reward system" of the brain. Fortunately, the urge to gamble didn't seem to show up in folks who only took the major Parkinson's drug, with carbidopa to slow its effect.
There's still no cure for Parkinson's disease, of course, so anything that prevents or delays its onset would be a welcome development. Harvard researchers found that vigorous regular exercise early in adult life cut in half a man's risk of developing Parkinson's later on. Physical activity was also associated with a decline in Parkinson's in women, although the drop was not statistically significant. Still, there are plenty of other reasons--from helping the heart to improving one's mood--to get moving.
POLIO This is the year polio was supposed to be wiped out. That didn't happen, but the number of cases worldwide dropped from 350,000 in 1988 to 1,499 reported cases as of mid-November, and global-health experts are optimistic about eliminating the paralytic scourge in 2006.
There have been glitches, however; religious concerns have kept people from getting inoculated, not just in developing countries but also here at home. Five children--all from a group of Amish families in central Minnesota that don't believe in vaccination--developed polio this fall, something that hasn't happened in the U.S. since 2000.
PRESCRIPTION DRUGS The biggest expansion of the Medicare program in 40 years began this November when seniors and other eligible beneficiaries started enrolling in new plans to cover prescription-drug costs. Officially called Medicare Part D, the plans are offered by private insurers and may cut costs for some participants as much as 50%.
That doesn't necessarily mean they are easy to understand. Medicare patients who currently pay for all their prescriptions out of pocket will benefit from just about any plan they choose. If they already have some prescription-drug coverage, however, say, as part of a union benefit or retiree health plan, they must be prepared to do some real digging to understand if switching makes sense. A good place to start is to call 1-800-MEDICARE or to visit medicare.gov Anyone who decides to enroll, however, should sign up as soon as possible. Delaying past May 15, 2006, will increase the premiums.
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RIGHT TO DIE Americans have often fought bitterly over how and when to end human life. But there's never been a battle quite like the one that culminated last March, when doctors removed the life-sustaining feeding tube from Terri Schiavo, a Florida woman who had been languishing in a persistent vegetative state--awake but unaware--since 1990. The battle that began in private between Schiavo's husband and guardian Michael, who insisted she did not want to be kept alive in such a condition, and Schiavo's parents, who vehemently disagreed, played out on the public stage. The issue sparked fierce debates in Washington, where then House majority leader Tom DeLay called the removal of the tube an "act of medical terrorism" and Congress passed a midnight law giving federal courts a chance to make doctors reinsert it. The courts refused to hear the case, and Schiavo was allowed to die. An autopsy showed that her brain had atrophied and that her condition was, as her husband had claimed, irreversible.
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SCHIZOPHRENIA Americans spend about $10 billion a year for antipsychotic medications, but are we getting our money's worth? Not according to a landmark government-funded trial published in the New England Journal of Medicine. It found that Risperdal, Seroquel and Geodon, three of the new "atypical antipsychotics" that doctors widely prescribe to treat schizophrenia, are no more effective--and no safer--than an older and much cheaper generic drug called perphenazine. The study was another reminder that the flashy new compounds coming out of pharmaceutical labs may not be worth the high price tags they command. Perphenazine, for example, costs about $50 a month, while the new antipsychotics can easily run 4 to 10 times as much or more. Zyprexa, a fourth atypical antipsychotic included in the study, helped more patients for longer than the other drugs, but it was also more likely to cause severe weight gain, high blood sugar and high cholesterol. By the end of the study, 74% of patients had abandoned their medicines because they either didn't work well enough or caused intolerable side effects.
SEXUALLY TRANSMITTED DISEASES The lessons of the '70s and '80s seem to have been lost on this generation of sexually active young adults. The Centers for Disease Control and Prevention (CDC) reported a rise in cases of early-stage syphilis last year (up 29% from 2000, largely among gay men) and chlamydia (up nearly 6% since 2003). By contrast, rates of gonorrhea dipped to their lowest level since 1941, when record-keeping began.
Ironically, one group that is still at high risk for sexually transmitted diseases is the millions of teenagers who made public "virginity pledges" to abstain from sex until marriage. A report in the Journal of Adolescent Health found that compared with other teens, those who made the pledge are more likely to experiment with oral and anal sex, are less likely to use condoms and are just as likely to contract sexually transmitted diseases. As a group, however, pledgers do tend to wait longer to lose their "technical" virginity.
SUDDEN INFANT DEATH SYNDROME In October the American Academy of Pediatrics revised its guidelines for preventing sudden infant death syndrome. Key recommendations include giving babies a pacifier at nap time and bedtime but only when they are between 1 month and 1 year old--after breastfeeding has been firmly established and before dental problems are likely to arise. The academy also advises parents to place babies on their back to sleep, never on their side or front, and to put them to sleep in their crib, not the family bed, where they risk being strangled or suffocated.
SLEEP Failing to get a good night's sleep can be hazardous to your health, even if you are not a teamster or an airline pilot. For one thing, sleep deprivation goes hand in hand with obesity. In a study of just over 1,000 patients, subjects with normal body mass indexes got 1.86 more hours of sleep a week than those who were overweight. Sleep disorders such as obstructive sleep apnea (OSA) pose even graver risks. Not only does OSA cause raucous snoring, but it can also stop your breathing as often as 60 times an hour, which may strain your cardiovascular system. Studies show that moderate to severe OSA significantly raises your risk of stroke and sudden death from cardiac causes. The condition can be effectively treated, however, with masks that force air through your nose while you sleep.
SMOKING It's no secret that smoking is bad for you, but secondhand smoke is proving more dangerous than anyone suspected. Two studies showed that women who don't smoke but live or work with people who do have a 27% increased risk of breast cancer and are as much as twice as likely to develop cervical tumors. Another study showed that children raised by smokers have as much as three times greater risk of developing lung cancer when they grow up. A fourth study found that the grandchildren of women who smoked while pregnant are more than twice as likely to develop asthma as children whose grandmothers did not. And environmental smoke, even at low levels, was associated with lower reading, math and logic skills in children and teenagers.
The good news is that eliminating secondhand smoke really makes a difference. In 2003, Pueblo, Colo., banned smoking in restaurants, offices and other indoor spaces. In the 18 months following the ban, the number of heart attacks among Pueblo residents fell 27%.
STATINS The more than 10 million Americans who take statin drugs to lower cholesterol may be enjoying some unexpected benefits. New studies suggested that regularly taking medicines like Lipitor, Lescol, Pravachol and Zocor may halve a patient's risk of developing colon and advanced prostate cancers while reducing their risk of pancreatic and esophageal cancers more than 50%. Another study showed that patients who aren't on statins can cut their risk of death following a heart attack more than 50% if they take them before hospitalization and within 24 hours after the attack. Doctors think the cholesterol- and inflammation-reducing effects of the drugs may even help Alzheimer's patients; in a three-year study published in the Journal of Neurology, Neurosurgery & Psychiatry, statins appeared to slow the progress of the disease.
STEM CELLS Before admitting to ethical lapses last week, the same Korean researcher who created Snuppy the cloned puppy (see "Cloning") shocked Western scientists by producing 11 custom-made human-stem-cell lines from the cloned skin cells of individual patients. The labs' procedure was surprisingly efficient; Woo Suk Hwang and his team needed on average only 17 human eggs to grow each of the cell lines (in contrast to the 242 eggs they needed to make a single stem-cell line just 15 months earlier). Research like this may someday lead to treatments for a wide range of disorders, including Alzheimer's and Parkinson's diseases and spinal-cord injuries.
Meanwhile, U.S. scientists made progress in the field without having to sacrifice human eggs or embryonic tissue. At Duke University, doctors used umbilical-cord blood to save babies born with Krabbe disease, a rare and usually fatal genetic disorder. The illness, which prevents brain development and causes rapid deterioration and death, was immediately halted by transplanting another baby's cord blood--and the stem cells it contained-- into infants with the Krabbe defect.
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TEA Curling up with a nice cup of hot tea can do your body a lot of good--at least if the tea you're drinking is chamomile. A British study of 14 tea lovers found that downing five cups of chamomile tea a day increases the body's levels of compounds that may boost the immune system and relieve muscle spasms like those that cause menstrual cramps. Drinking too much instant tea, on the other hand, can be harmful. A Washington University study reported that some brands of instant tea contained dangerous levels of fluoride--as much as 6.5 parts per million, well over the 4 p.p.m. that the EPA allows in drinking water. Ingesting high levels of fluoride can cause bone pain, bone spurs and fused vertebrae.
TEETH Here's an often overlooked aspect of prenatal care: Mom's dental health. A new study published in the Journal of Periodontology showed that pregnant women with high levels of an oral bacterium associated with cavities are at high risk for delivering preterm, low-weight babies. Doctors think problems occur because bacteria travel from the mouth to the uterus and interfere with pregnancy. One way to keep teeth strong is to watch what you drink--and how you drink it. Researchers writing in the journal General Dentistry reported that organic acids in sports beverages may cause irreversible damage to tooth enamel over time--damage 3 to 11 times as great as that caused by colas. They recommended minimizing the effect of the acids by chugging rather than sipping the drinks.
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VACCINES If all goes well, the FDA could approve the first vaccine for cervical cancer by 2006. A large-scale study presented at a meeting of the Infectious Diseases Society of America in October found that Merck's experimental vaccine Gardasil was 100% effective against two strains of human papillomavirus that cause 70% of all cervical cancers. Another experimental Merck vaccine was tested this year for protection against shingles, the painful blistering disorder caused by the chicken-pox virus. In a trial of more than 38,500 adults 60 and older, the vaccine cut the risk of shingles by more than half. It also reduced by two-thirds the symptoms of chronic pain that afflict many of the 1 million U.S. adults who develop shingles each year.
An older vaccine got a new look when a CDC advisory panel backed the broader use of a vaccine for hepatitis A in 1- and 2-year-olds, estimating that routine use in children could cut the national caseload of the disease by 180,000. For teens and adults, the panel recommended a booster shot for pertussis, or whooping cough, a highly infectious, long-lasting illness that has been on the rise since 1976, particularly among adolescents. The shot could prevent 1 million cases a year.
If you're still wary about the risks of inoculation, consider this: a study in J.A.M.A. reported that routine childhood vaccinations do not increase children's vulnerability to unrelated diseases or infections. What's more, in a survey of 302 pediatricians that was published in the Archives of Pediatrics & Adolescent Medicine, 39% of doctors said they would stop caring for families who refused vaccinations.
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WAIST Your belt size may have more to do with your health than your vanity. New research showed that a large waist is associated with insulin resistance and metabolic syndrome--a precursor condition to cardiovascular disease and diabetes--in children and adults. A study of 27,270 men found that thick-in-the-middle guys--with 40-in.-to-62-in. waists--are 12 times as likely to develop Type 2 diabetes as men measuring 29 in. to 34 in. around. Studies also supported the contention of many experts that the waist-to-hip ratio is a more accurate measure of obesity and a better predictor of heart-attack risk than the widely used body mass index.
WATER Staying hydrated while exercising is important, but drinking too much water can be as dangerous as not drinking enough. Research showed that hydrating too much over the long haul--during a marathon, say, or a long-distance bike ride--dilutes the blood's salt content and can lead to hyponatremia. The body's cells, including brain cells, absorb the excess fluid and swell, and growing pressure in the skull can cause permanent damage or death. Hyponatremia is surprisingly common; in a study of 488 runners of the 2002 Boston Marathon, 13% were over-hydrated. Many of the symptoms of hyponatremia--nausea, dizziness, confusion, lethargy--mimic those of dehydration. The authors of the Boston study offered a handy way to test yourself: if you weigh more after exercising than before, you're drinking too much.
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ZAMBIA Public health officials will be watching Zambia closely over the next few years. With a $35 million grant from the Bill & Melinda Gates Foundation, the country has launched Africa's first nationwide antimalaria initiative, with a three-year plan to get bed nets, medicines and indoor insecticides to 80% of the population. The goal is to reduce deaths from malaria 75% and to show the rest of the world--including donor countries-- that malaria can be contained using low-cost tools that are readily available.
ZINC Got zinc? A study by researchers at the Grand Forks Human Nutrition Research Center in North Dakota found that seventh-graders who took 20 mg of zinc--double the recommended dietary allowance--five days a week for as long as three months outperformed their peers on tests of memory, word recognition, attention and learning. Halfway around the world, a study of Bangladeshi children demonstrated the life-saving health benefits of minimal levels of this essential mineral. In a yearlong study of 1,621 children ages 2 months to 1 year, zinc supplements either prevented or lessened symptoms of pneumonia and diarrhea--conditions that kill millions of children each year in the developing world. Compared with the placebo group, children who took a weekly 70-mg dose of zinc had an 85% reduced risk of death.