A Breath of Fresh Air – But is it bad for you?

12/08/2015

Healthy Living - December 8, 2015
William Sturrock, MD

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For centuries the pendulum of prevailing medical opinion has swung back and forth on the question of whether breathing cold air was harmful or healthful. In the Middle Ages, before there was any understanding of germs, the cool night air was actually suspected as a source of illness. This “Miasma Theory” of the origins of epidemics was also widely held in ancient Chinese and Indian medicine. Given the poor state of sanitation in the urban centers of antiquity, where heaps of animal manure, human waste and rotting vegetable matter were a common sight on those crowded streets and alleys, one can easily understand how they believed the air itself could cause epidemics such as cholera, plague, and typhus. Physicians routinely advised their patients to make sure their windows were tightly closed, especially at night, to avoid the influx of the dangerous night air.
 
By the mid-1800s, however, the work of researchers such as Pasteur and Koch led to the understanding that microbes were the true cause of infectious disease. Physicians began to look at the robust health of country dwellers and even aboriginal peoples such as the Inuit who spent most of their lives in the open air and did not develop the diseases of urban living. A new movement arose that focused on”holistic” concepts that exercise, strict hygiene, and pure foods (often combined with avoidance of “sinful practices” to include the consumption of all alcohol, caffeine products, and even sexual activity!) were the keys to good health and long life. The Sanatorium movement began as a treatment for tuberculosis based on the belief that the disease could be stopped by encouraging those suffering from this usually fatal condition to spend hours breathing cold air while bundled in blankets on open porches in facilities that were built all over northern Europe. In the U.S., the first sanatorium was built at Saranac Lake in New York in 1885, and these institutions flourished until streptomycin was discovered in 1943 as the first antibiotic effective against TB.
 
Other groups of physicians that extolled the benefits of the cold night air included ENT and lung specialists of the early 1900s. In particular, they believed that sinus infections and inflammation of the bronchial tubes were worsened by breathing the hot dry air associated with central heating. Patients were now encouraged to open their bedroom windows at night, especially in the winter, to get relief from the less healthful indoor air.
 
So what is the truth about breathing cold air? Research does tell us that sudden inspiration of cold air can cause a reflex constriction of the airway like that seen in asthma.  Although this is not severe in all people, those who already have a diagnosis of asthma can suffer from this reaction, especially if combined with exercise.
 
More serious is the potential for cold air to cause angina, or decreased oxygen in the heart, potentially leading to heart damage or even sudden death. A study in Scandinavia found that when healthy subjects exercised in a temperature of 15 degrees, they did not suffer any heart problems. However, when the air was cold than – 20 degrees, the increase in blood pressure and increased need for oxygen could be potentially dangerous.  It is a well-known medical syndrome that individuals who may already have some restriction of coronary artery flow are at higher risk for heart attacks when exercising in the cold, similar to what someone might encounter when shoveling or even walking in deep snow.

So what is the best advice for those who are exposed to cold air?
 
  1.  First, to prevent lung or sinus irritation, keep indoor winter air temperature as cool as you can tolerate while wearing a sweater or warm clothes (65 to 70 degrees Fahrenheit for most people). It’s not necessary to open your windows in the winter if you keep the humidity level around 30 to 40%.
  2. If you have known exercise or cold-induced asthma, use your inhaler 5 minutes before exposure, especially if you are planning to do outdoor work.
  3. If you plan to do winter sports or even heavy work like snow removal, begin 4 to 6 weeks before the cold winter begins with an aerobic exercise program of gradually increasing intensity of 20 to 40 minutes at least 2 or 3 times per week.
  4. If you already have known heart disease or a lung condition like COPD that decreases your oxygen with exercise, then it’s time to hire that nice boy that lives around the corner to shovel your walkways. Cold air might be more dangerous for you than the “miasmas” that arose from the polluted swamps of medieval times.