In the mid-19th century, a revolution took place in science and medicine. Germs were discovered, and with their discovery, the “germ theory” of disease was born. Of course, today we all know that infections are the result of germs that get into us from another person, from an animal, or from the environment. But, grandmas have long had their own theories about what causes illness.
Many of us grew up with grandma teaching us that illness came from being underdressed in cold weather, or overdressed in warm weather. If our hair was wet when we went outdoors, guaranteed sickness. If our feet got wet in the snow or rain, sick again – we had caught a chill! Food and drink, of course, were also critical determinants of health. Hot was healing – chicken soup and oatmeal; but heaven help the poor soul who drank something too cold on a cold day – or, for that matter, on a hot day. Ice was a public health menace. Hot tea with honey was curative; ice tea – are you kidding? If we got enough sleep, we stayed healthy – if not, sickness. Our grandparents thought that stress made us more likely to get sick, and that exercise kept us healthy. The truth about infections rests somewhere between grandma and science. The following paragraphs briefly examine the science behind grandma’s wisdom. For much more on traditional and non-traditional approaches to germ defense, see Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections (ASM Press, Washington, D.C., 2008).
Sleep
Sleep-deprived rats develop severe, life-threatening infections. In humans, laboratory tests show dramatic effects of sleep-deprivation. When blood tests are done on sleep-depressed adults, all test-tube measures of immunity are weakened. But, what do clinical studies show about the impact of sleep and sleep deprivation on actual infections? Do our kids really get sicker if they don’t get adequate sleep? Although there is no research on sleep-deprivation in kids, adult studies have shown that lack of sleep results in a weakened immune system. In one study, 10 days after receiving the flu vaccine sleep-deprived adults had less than half the amount of flu immunity (protective antibodies measured in the blood) compared with a normal sleep group. Grandma was probably right – your kids’ immune systems need adequate sleep (for much more, see Chapter 11 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections).
Stress
Childhood shouldn’t be stressful – how many of us would instantly trade our adult hassles and headaches for the carefree childhoods we remember? And yet, anyone lifting our kids’ backpacks after school or watching them try out for their competitive soccer teams knows that kids do have stress. Science has looked at two types of stress: short-term (like the big test or the big try-out), and long-term (like divorce or family illness). The effects of the two types of stress are opposite: while long-term stress does weaken the immune system, short-term stress actually boosts immunity! Along with adrenaline that’s released under stressful conditions, the body releases other chemicals that boost the immune system (for much more, see Chapter 11 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections).
Weather and wardrobe
Will kids get fewer infections if they bundle up in the cold and wear their boots in the rain? Let’s start with the term the “common cold”. It is not a coincidence that the word “cold” applies to both the weather and the illness – that language linkage exists in many languages besides English. The sniffles are called a “cold” because everyone form the beginning of time knows that colds are more frequent when it’s cold outside. But now there’s science as well as language to support the relationship. In a study done in 2005, 90 volunteers sat with their bare feet in a bucket of ice water for 20 minutes, while another 90 “controls” kept their feet in an empty bucket, still wearing their socks and shoes. Nearly 30% of the cold feet group developed common cold symptoms within the next 5 days, compared to only 9% of the warm-and-dry-footed volunteers. How can this be? How can 20 minutes of an icy foot bath cause 3 times the number of colds? The theory is that we are all occasionally infected with respiratory viruses; oftentimes we don’t get sick because our immune system halts the virus in its tracks. If, however, we experience a body chilling event while the virus is loitering in our nasal passages, our defenses are temporarily lowered and the virus gets the upper hand, making us sick (for much more, see Chapter 11 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections).
Exercise
The strongest scientific evidence in support of grandma’s wisdom involves the role of exercise in the health of our immune systems. The research has been done in two areas – regular, moderate exercise and extreme exercise (e.g. marathon running). Several well-done clinical trials in adults have shown that daily or almost-daily moderate exercise reduces sick days by half compared with non-exercising adults in the same studies. A large study of nearly 550 adults examined the relationship between physical activity and days of upper respiratory tract infections (the “common cold”). There was nearly a 30% reduction in episodes of respiratory infections in the group with the highest level of regular, moderate physical activity. It’s as if exercising gets our immune systems “in better shape” to respond when challenged by infection, even as exercise gets our muscles and cardiovascular system in better shape to respond to other challenges. But, it’s a whole different story with “extreme” exercisers. In highly active adults, such as elite marathon runners, more than a dozen formal clinical studies have now confirmed that there is a markedly higher rate of upper respiratory infections (the “common cold”) following marathon running (for much more, see Chapter 11 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections).
Chicken soup and honey
Chicken soup has been prescribed by grandma for centuries. In modern times, this wonderful elixir has been given to treat the common cold and the flu. There are several theoretical reasons that chicken soup might help these conditions, but there is no actual scientific proof that chicken soup prevents or treats infections. Even though we can’t prove grandma right on this one, feed it to your kids whenever they are sick – it tastes great, makes the house smell wonderful, and shows your kids that you love them. Serve it to your kids when they’re not sick, too – same reasons.
Over-the-counter cough medicines don’t work in kids and pose a risk for side effects and for accidental overdose (because kids like the taste of some of these products and will drink from an open bottle left in reach). Grandmothers have long known that honey (in tea, in milk, or straight up) makes kids with coughs and colds feel better. A study in 2007 proved that, again, grandma is right. Honey performed better than cough medicine or no treatment at all in easing the cough and helping kids sleep through the cough. (A warning though – honey should not be given to kids under 15 months of age because of the risk of botulism) (for much more, see Chapter 8 in Germ Proof Your Kids – The Complete Guide to Protecting (without Overprotecting) Your Family from Infections).
Conclusion
Listen to your grandmother!