This month, Dr. Sydney Spiesel discusses the benefits of drinking coffee, a great new way to prevent infant anemia, whether acupuncture works, lightning and cell phones, and the link between depression and heart disease. (Click here and here for the last two columns.)
Coffee: Drink more.
Effects: As I write this, I am savoring an especially enjoyable cup of coffee, made so by the knowledge that sipping it may decrease my risk of developing adult-onset diabetes (though, sadly, the slab of gooseberry pie I ate a few minutes earlier almost certainly neutralized the beneficial effect). Coffee is one of the most widely consumed beverages in the world. We like its taste and, even more, its pharmacological effects, including an increased sense of alertness and ability to counteract sleepiness. Medically, coffee's most important active ingredient, caffeine, has only a few uses: It helps some headache sufferers, and it's sometimes administered to infants (especially premature ones) who need to be pharmacologically "reminded" to keep breathing. Other effects of caffeine are not so benign. It acts on the kidneys as a diuretic and can cause jitteriness, rapid heart rate, and loose stools. Extremely large doses can cause seizures and—extremely rarely—death.
Antioxidants: Coffee ought to be beneficial by virtue of its high content of antioxidants, natural chemicals that bind and neutralize a group of unstable materials in body cells that, among other things, damage DNA, causing the effects of aging and the cellular changes that lead to cancer. Coffee contains more of these antioxidants than green tea and red wine. Sadly, it's been hard to absolutely demonstrate the value of the antioxidant properties of these beverages, though most of us doctors believe in them anyway.
Diabetes: The association between coffee-drinking and reduced risk of adult-onset diabetes, on the other hand, has now been well-established by a number of studies that followed many, many patients in a wide variety of geographical locations. Often, in big epidemiological studies, one can't tell whether the observed association is the result of causation—drinking coffee protects against diabetes—or of two loosely related phenomena. Imagine, for example, that people with heavier, diabetes-prone bodies might find undesirable a beverage that's a stimulant and mildly diuretic. Still, the coffee studies add up: If many studies produce similar findings after drawing from diverse populations and taking care to rule out other, coincidental, factors as causes, it becomes increasingly likely that we are dealing with causation, not mere association. In addition, a dose-response curve—the more coffee drunk, the less diabetes risk—adds a lot to the causation argument.
New findings: That is what we have for coffee-drinking and diabetes risk. I counted more than seven good studies reporting that reduced diabetes is associated with coffee-drinking. The most recent, a study by Mark Pereira, Emily Parker, and Aaron Folsom of the University of Minnesota, followed more than 28,000 post-menopausal women over 11 years. The research team found an almost linear decrease in the risk of developing diabetes based on how much coffee their subjects drank on average. Women who drank six or more cups a day showed the most benefit. An earlier study conducted in Finland, which has the highest per-capita consumption of coffee in the world, found the effect especially beneficial for the 16 percent of the study population who drank 10 or more cups a day. Interestingly, the new study showed that the beneficial effect could not have been due to caffeine, magnesium, or phytic acid—each of which previously had been suspected of playing a role. Actually, decaffeinated coffee does more to decrease the risk of diabetes than the high-octane version. And the Finland study found that filtered coffee was more effective than boiled.
So, though we still have no idea of what in coffee protects against developing diabetes, the drink looks like that rarity: something you desire that might be good for you.
Anemia: An assist from the umbilical cord.
Iron deficiency: You have to love a simple intervention that promises to improve the lives of many patients. Camilla Chaparro, Kathryn Dewey, and their colleagues at the University of California at Davis, the Mexican National Institute of Public Health, and the Luis Castelazo Ayala Hospital in Mexico City have given us just such a prize in a paper published in the Lancet. In developing countries perhaps half of all children become anemic by their first birthday. The cause is usually iron deficiency, related to maternal iron deficiency, maternal blood loss associated with childbirth, or early infant feeding practices using iron-poor formula or foods. The deficiency often worsens with time because of the chronic blood loss associated with many intestinal worms that infest children in the tropics, and because poor families can't afford much meat. There is some disagreement in the scientific literature, but many experts believe that anemia in early childhood has negative—and perhaps irreversible—effects on development.
The fix: Chaparro and her colleagues tested the effects on iron levels in infants of delaying the clamping of the umbilical cord until two minutes after birth. Following more than 350 infants, the researchers found that a two-minute delay (which allowed the return of about 4 ounces of the baby's blood that's temporarily held in the placenta and cord vessels) led to a substantial decrease in anemia at 6 months. The intervention was most effective for babies at greatest risk: those born to iron-deficient mothers, with low birth-weights, or who don't get iron-fortified formula.
The usual practice: The usual practice of clamping the cord right away (an average of about 17 seconds after birth in Mexico City) is standard hospital practice everywhere. The idea is that quickly clamping and cutting the cord will make it easier to attend quickly to the needs of both newborn and mother. In addition, hospitals can finish labor and delivery faster, which has some institutional advantage. And it is sometimes argued that the extra increment of blood produced by delayed cord clamping might cause the baby to wind up with too much blood in his system, increasing circulatory difficulties and the risk of jaundice. But this study did not encounter either adverse effect.
In short: an easy, free, safe intervention that is likely to give a leg up to newborns in developing countries. What more could one ask for?
Acupuncture: Of pains and needles.
Complementarytherapies: Acupuncture, nutritional supplements, homeopathy, and naturopathy seem to many to offer safer, less invasive, more "natural" ways to deal with bodily woes than conventional medicine. They appeal to the desire for the spiritual and the mysterious. They may be less expensive. Their practitioners are often warmer and less pressed for time; they appear to pay attention to our whole selves and not just the broken parts. And some patients relish the increased autonomy: Instead of asking your doctor for a prescription, you can reach for a bottle of pills in the vitamin department of the supermarket.
The question: Do these treatments work? Sometimes yes and sometimes no. And sometimes for reasons practitioners don't anticipate. A particularly good example comes from a study reported recently in the Annals of Internal Medicine, conducted at the Universities of Heidelberg and Bochum in Germany by Hanns-Peter Scharf and his colleagues. The purpose was to help German insurers decide whether to pay for acupuncture, a practice of Chinese traditional medicine in which tiny needles are inserted to a shallow depth at specific locations in the skin.
The ailment: The researchers focused on acupuncture for osteoarthritis of the knee, a painful and debilitating joint inflammation that results from wear and tear in aging joints. It occurs in the majority of people by age 65, and in 80 percent by age 75. The knee is the most commonly affected joint. There is no cure. The standard treatment is anti-inflammatory drugs, which have their own risks; pain medication; and physical therapy. Ultimately, many sufferers have surgery, in which the damaged and painful knee joint is replaced with an artificial substitute.
The new study: Previously, some studies have shown the benefit of acupuncture for osteoarthritis of the knee, and others have not. For this study, Scharf and his colleagues looked at about 1,000 patients. The patients were divided into three groups. One group was treated with acupuncture. A second "sham acupuncture group" was treated with needles placed in locations that don't match those specified by traditional Chinese medicine. A third group received no needle treatments at all. All the patients had identical access to physical therapy and nonsteroidal anti-inflammatory medications. After 26 weeks, the subjects were all interviewed by people who didn't know which treatment they had received. The treatment was regarded as successful only if there was a 36 percent or higher improvement in knee function or pain relief.
The results: Acupuncture was clearly associated with improved function and pain relief. But it didn't much matter whether the treatment followed traditional Chinese medicine methods or consisted of needles placed in the wrong locations—both worked equally well. It is tempting to think that the physical act of placing needles caused the improvement, and that may well be the case. But there was another significant factor: The patients who got no needle treatment had substantially less contact with their doctors than the acupuncture patients, sham and real, had with their practitioners.
Conclusion: Should the German insurers pay for this complementary treatment? Well, without acupuncture, the patients in Scharf's study needed more physical therapy, more pain-killing medication, and more anti-inflammatory drugs. I sure wish I knew, though, what would happen if patients were treated without acupuncture but given more attention and care by their doctors.
Lightning and cell phones: Don't mix them.
The scare: A few weeks ago, the news was full of stories about the dangers of being struck by lightning while talking on your cell phone. Soon after, the press rescinded the warnings. Why? The original case report, described in a letter by three English ear, nose, and throat specialists to the medical journal BMJ, described a 15-year-old girl struck by lightning while talking on her cell phone in a London park during a storm. She was successfully resuscitated following a cardiac arrest, but a year later still suffered serious aftereffects (from the lightning strike? from the cardiac arrest?). The authors attributed the injury to the effect of a metallic conductor that had had contact with the skin and redirected the flow of lightning electricity from the surface of the skin to cause internal injury.
The physics: But the enormous electrical current of a lightning strike doesn't pass through the body (if it did, the resulting explosion would be impressive indeed). Instead, the electricity travels between cloud and earth along a highly conductive path of ionized air. When a conductor (that is, you or I) is near a field generated by a lightning bolt, electrical currents are induced in the conductor that can badly, even lethally, disrupt the nerve impulses that control the rhythm of the heart or the workings of the brain. But that is not the result of lightning electricity diverted into the body by a piece of metal near the skin. If metal acted as such a point of contact, we would see deep internal burns originating at metal jewelry or watches worn by people who are struck. We don't (though there is some danger of localized burns). Cell phones are mostly plastic and don't have much metal in them. So, the authors' idea that the phones are good conductors for diverting the lightning's current into a victim is especially implausible. After the initial scare letter, the BMJ published two letters written by people with substantially more technical knowledge who showed that the threat was spurious.
The problem: The medical journal editors should have thought to test the claim about the 15-year-old against what is known about the physics of lightning. And the media should have covered the correction with the same gusto it did the anxiety-provoking initial claim. Burying the correction increases our perception of the world as dangerous and misdirects our thinking away from the important questions about new technology (like its effects on our lives) toward nonexistent risks.
Conclusion: Is there any risk in using a cell phone in a thunderstorm? Actually, I suspect there is—the same danger as using it while driving: We become focused on the phone conversation and lose track of hazards. Which, in the case of lightning, means forgetting to seek shelter. That is probably the real lesson of the strike that injured the teenager in London.
Depression and heart disease: Will treating one help the other?
The new findings: There is no doubt that a powerful relationship exists between depression and heart disease, as demonstrated most recently in a study of more than 7,500 elderly women conducted by a research group under the direction of Mary A. Whooley of the San Francisco Department of Veterans Affairs Medical Center. The women were followed for seven years. During that time, only 7 percent of those with no depressive symptoms died, compared with 17 percent of women with three to five depressive symptoms, and 24 percent of those with six or more symptoms. The increased mortality was due to cardiovascular disease and some other conditions (chronic lung disease, pneumonia, accidents, and trauma), but not to cancer. Results like these have been replicated many times. Other studies show that depression also significantly worsens the prognosis for patients who already have coronary artery disease, making them 70 percent more likely to die.
Theunknowns: You'd expect the symptoms that often go along with cardiac disease—decreased tolerance for exercise, pain on exertion, a general feeling of weakness and ill health—to be quite capable of causing depression. However, it looks as if the depression usually precedes the heart disease and not the other way around. And as yet, there is no clear and unequivocal answer to explain the association. It is not even known whether the cause is more to be blamed on the behaviors that often accompany depressive feelings or on some biological factors that are caused by or at least related to depression.
Possible biological factors: Depressed people often have a higher resting heart rate, a higher level of the hormones that control blood pressure and heart rate, and a higher level of platelets (the blood elements that start the cascade leading to the formation of blood clots).
Possible behavioral effects: Depressed people are more likely to smoke, eat badly, exercise less, and fail to take medication. All of these factors, biological and behavioral, might well play a role in the relationship between depression and cardiovascular disease.
Conclusion: If we treat depression, can we help prevent cardiovascular disease and the increased risk of dying? Unfortunately, we don't know. But Dr. Whooley makes a strong case for identifying and treating depression in patients with cardiovascular disease, perhaps to help their cardiac health, and certainly to improve their quality of life.