Don't Cross Your Eyes...They'll Get Stuck That Way!: And 75 Other Health Myths Debunked (8 page)

Colds are not caused by the weather; they are caused by something that human beings pass from one to another. Colds are caused by rhinoviruses—a particularly unpleasant family of very similar viruses that cause runny noses, scratchy, sore throats, and general cold-related misery. With so many slightly different varieties, there are enough cold viruses to keep you getting sick again and again over the course of your life, without ever building up immunity to every single one. A new one can always come along and make you miserable with a cold once again.

Even if it is the virus that makes you sick, you might still believe the cold weather plays a role in getting that virus. Does the cold hurt our immune systems and make us more susceptible to getting sick? Actually, the opposite seems to be true. In a study of how the body’s immune system reacts to cold exposure, the researchers actually found that the immune system was stimulated when people were exposed to the cold. The cold weather increased the number and the activity level of some of the body’s key sickness-fighting cells—the white blood cells (specifically, the leukocytes and the granulocytes for those of you who want to look for them under a microscope). Other chemicals that the body produces to fight infections were also increased. So, the cold weather actually may help your body to fight sickness! In this study, the researchers also looked at what would happen if you were warmed up first or exercised before your cold exposure. As it turns out, getting warmed up before you go out into the cold helps your immune system work even better. The infection-fighting cells and substances in your body increase even more if you are warmed up before you go out into the cold.

Even though your body may have better sickness-fighting ability during the cold weather, it still seems like people get sick more often when it is cold outside, especially during the wintertime. The cause of the seasonality of colds (known to doctors as upper respiratory tract infections) is not entirely clear. One explanation is that people spend more time indoors when it is cold outside, staying in relatively close proximity to one another and allowing them to pass those colds around with their sneezing and coughing. Another idea that one expert suggests is that cold weather keeps the airways in your nose cooler, and this decrease in the temperature of the inside of your nose gets in the way of how the nose works to protect you from colds. Even though the rest of the body’s immune system seems to be activated by the cold weather, when the nose is exposed to cold temperatures, the tiny hairs and mucus that keep things moving out of your nose might not work as well. This could give the cold viruses a chance to settle in and make you sick. While these studies show how the cold theoretically hinders how well your nose works to protect you, there is not yet wide-scale evidence that this is the reason people get sick in the wintertime.

There is a cycle of when certain viruses come and go. The rhinoviruses that cause most colds actually peak in the spring and fall, perhaps contributing to the belief that we get sick when the weather changes. Other families of viruses peak in the winter—viruses like those of the influenza family, which usually cause the much worse flu, or respiratory syncytial virus (RSV), which can make babies very sick and usually cause a cold in adults. We do not have a good explanation for why particular parts of the world see these viruses at particular times, but it is not necessarily the cold weather that brings them around. Don’t blame Frosty!

Plus, it is important to remember that the practical effects of cold exposure on getting sick have been tested. When scientists test what the cold virus does in humans, there is no evidence that the cold weather makes you more susceptible to infection. In study after study where scientists put cold viruses directly into people’s noses and then measure who gets infected, the people who are forced to be in very cold conditions are no more likely to get infected with a cold than the people who got to stay in warm conditions.

Researchers have even studied the question of whether or not wearing enough clothes when it is cold will make you get sick. In one study, volunteers were divided into groups where some people had to be in very cold conditions, but were allowed to wear warm coats; others had to be in their underwear in 60 degree temperatures; and a third group got to be the lucky ones in 80 degrees of warmth. It turns out that it didn’t matter at all how cold it was or what you were wearing; everyone with the virus stuck into their nose had the same risk of getting infected by that virus.

There has been one study that suggested that if a particular body part got very chilled, you were more likely to report experiencing cold symptoms. In this study, all of the volunteers were again exposed to the cold virus, and then some of them had to keep their feet in very cold water. Those who had chilled feet were more likely to report cold symptoms later on. Does this mean that you better make sure you are wearing warm socks and boots? While having cozy feet is always nice, it won’t necessarily affect whether you get sick. This study could not establish a cause-and-effect relationship. While icy toes and having a runny nose might be linked in some way, it could be that you just notice your runny nose more because you remember how cold your feet were and have been terrified about getting sick. There is no evidence to prove you are more likely to get a cold from leaving a body part without warm enough socks or gloves.

What about wearing a hat? Your mother may have convinced you that the reason the cold weather was finally going to make you sick was because you did not cover your head. Many people have heard that covering your head is the most important thing you can do to stay warm since you lose the majority of your body heat through your head. This is a myth, too! You do lose body heat through your head, but you lose heat through any part of your body that is uncovered. The amount of heat loss depends on the surface area of what is uncovered. You don’t lose any more heat from your uncovered head than you do from an uncovered arm or an uncovered leg. The one thing that is special about the head is how we feel about heat when our heads are covered or uncovered. Studies have shown that how warm people feel when their head is covered is out of proportion with how warm they actually are. “Thermal sensation,” or feeling warm, is increased when you wear a hat more than your actual body heat is increased. Along with the studies examining whether people who are not dressed warmly enough get sick, scientists have studied whether cold viruses will infect you if you are not wearing a hat. However, bald people do not become sick more easily than people with hair. There is no evidence that people who go without hats get sick more often. Similarly, there is no evidence linking baldness (where your head is always less covered) with any sicknesses except sunburn and potentially skin cancer.

If you are cold and your head is still uncovered, then by all means put on a hat! But a hat alone is not a guarantee of warmth or health. You may be tempted to stay inside or wear extra layers of clothes when it is cold outside. There is certainly nothing wrong with being comfortable, but you should be reasonable about why you take your precautions. The cold weather may make you uncomfortable, but it is not going to make you sick.

Cough and Cold Medicines

I have just the thing for that cold … Over-the-Counter Cough and Cold Medicines

When you are suffering from a terrible cold, that long aisle at the drugstore with its myriad cough and cold remedies appears promising. The various pills and syrups promise to improve your stuffed-up or runny nose, your hacking cough, your scratchy throat, or all of the above. Yes, please! But you may find it hard to know which one will work best. What might be even harder to grasp is that none of these medicines will actually cure your cold. Colds and coughs are almost always caused by viruses, and none of the medicines on the drugstore shelf are designed to kill viruses. Instead, they are supposed to help with your symptoms, such as making your nose run less or relieving your congestion.

Antihistamines are one type of medicine commonly used to treat the symptoms of the common cold. When scientists looked at combined results from thirty-two studies of antihistamines involving almost 9,000 people, they do not find any improvement overall from using an antihistamine by itself for either children or adults. In the small subset of patients who did report some improvement after taking an antihistamine, 81 percent of the patients still had cold symptoms even with this improvement. For children, antihistamines did not perform any better than a placebo in any of the studies.

Many over-the-counter cough and cold medicines are combined medicines that include both an antihistamine and a decongestant. In studies involving children, these combined antihistamines and decongestants did not have any effect; they simply did not improve cold symptoms for children under five. For older children and adults, though, there was a small benefit. Similarly, decongestants alone seem to have some benefit for patients with colds. So, if you want to improve your nasal stuffiness or congestion, a combined antihistamine and decongestant or a decongestant alone might help you, but an antihistamine alone will not make a difference.

Some studies have shown that nasal sprays can relieve congestion for approximately one day, but there is no evidence that using them again and again will help you. In fact, many people develop a “rebound” runny nose or congestion when they use these nasal decongestants for more than one or two days.

When it comes to medicines that relieve your cough (antitussives), we again find that most do not work when you look at the science. A review of studies evaluating what helps or does not help with coughs in adults found that codeine did not help with coughs any more than a placebo or fake medicine did. Another common anti-coughing medicine called moguisteine did not work either. There was some evidence that a medicine called dextromethorphan (you see this in medicines labeled “DM”) did help with coughs; two of the studies showed that dextromethorphan worked better than a placebo, though one study did not show that dextromethorphan helped at all. That is not a ringing endorsement for dextromethorphan, but at least there is the possibility that it works. For children, none of these anti-coughing medicines seems to work at all, including codeine and dextromethorphan. Studies of other pediatric cough syrups did not show any benefits for children’s coughs or other symptoms.

Another kind of medicine for coughs is an expectorant. An expectorant helps to dissolve or thin your mucus, which may make it easier to cough up that nasty stuff in your lungs. For adults, one type of expectorant called guaifenesin seems to help those who take it four times a day to cough less hard and less often; however, there is no evidence that this type of medicine works for children.

You may have noticed that children do not seem to benefit from any of these medicines. Although over-the-counter cough and cold medicines are frequently used in children, the scientific data suggest that they do not actually work! In six randomized placebo-controlled studies testing the use of cough and cold medicines in children under the age of twelve, the scientists could not find any difference between taking a cough and cold medicine or taking a placebo medicine. No one knows exactly why these medicines do not work for kids, but the science is clear that they do not!

Even worse than not working, these medicines have a higher risk of negative side effects in children, especially in the youngest children. In safety data from the United States Food and Drug Administration (FDA) that report on the use of these medicines over the course of thirty-seven years (1969–2006) for children younger than six, fifty-four children were deemed to have died because of side effects from decongestants and sixty-nine died from side effects from antihistamines. Usually, an overdose of these medicines was responsible for the child’s death. Children can actually die from these medicines! Many more children have bad side effects from these medicines that do not kill them, but that require medical treatment. In the United States in 2004–2005, 1,519 children under the age of two had to go to the emergency room for treatment because of negative side effects from over-the-counter cough and cold medicines. These side effects can include serious conditions like abnormal heart rhythms and loss of consciousness. Because of these bad side effects (and also because these medicines don’t work!), the FDA has issued more strict advisories cautioning against the use of these medicines in young children, especially for children less than two years old. As pediatricians, we advise you not to give your babies and toddlers these medicines. And talk to your doctor before you administer them to your older children.

In conclusion, no over-the-counter medicines for colds and cough are effective for kids, and many are not effective even for adults. Dextromethorphan and guiafenesin for cough, antihistamine-decongestant combinations for general symptoms, and at least the first dose of nasal decongestants may offer some benefit for adults. For children, none of these medicines offers clear benefits and many have been associated with bad side effects, so they are best avoided altogether.

Croup

Cool mist will help your child’s croup

When babies get croup, they have a terrible, barking cough and can get to a point where they have a lot of trouble breathing. Pediatricians will usually recommend that parents put these babies in a humid place, like the bathroom with the shower running, in order to help with the cough and breathing difficulties. Doctors will also sometimes use special plastic tents with humidified air or humidified breathing treatments when croup sends a baby to the hospital. Parents may even start using humidifiers in order to prevent babies from having these problems. If you ask most doctors, they would say that humidified mist will help your child’s croup. Doctors have used mist like this since the nineteenth century, when physicians felt that the steam from teapots and hot tubs alleviated croup symptoms.

Pediatricians and parents alike may be surprised to learn that there is no evidence to support using humidified air to treat croup. There have only been a few studies looking at this, but none have shown a benefit. A study from 1978 in Britain showed no improvement when using a saline mist (nebulized saline) for children with croup. Another study, done in Australia in 1984, randomized children with croup to either a normal environment or to an enclosed cot where they were surrounded by cool, humid mist. The children were evaluated throughout twelve hours, and there were no differences between the groups in terms of their clinical conditions, vital signs, and the amount of oxygen in their blood. Two subsequent randomized, controlled studies done in Canada showed no evidence that humidity improved croup symptoms of children in the emergency department. A study of dogs showed that airway resistance (which is higher than it should be when a child has croup) actually got better with dry air than with moist air. In fact, both cool dry air and hot dry air created lower airway resistance than cool moist air or hot moist air. A meta-analysis that searched for all of the available studies testing humidified air for croup in children, found that the combined studies did not support using humidified air for croup. It just does not work.