Winter: Friend, Foe or Frenemy to Humankind?

Ah, fresh snowfall.

Simply close your eyes and imagine.

Full, puffy white flakes buoyed by the crisp winter air drift gently from the heavens.  A blanket of virginal white snow forms amidst the bustling holiday market in the warmly lit historic town center – reminiscent of that Nathaniel Currier and James Merritt Ives piece you remember above the fireplace in your grandparents’ home.

Suddenly, a car honks and your eyes snap back open to the intersection.

Right now:

• Airlines have cancelled flights ahead of winter storm Jayden warnings.  Again.
• A polar vortex for the generations is bearing down on the Midwest to make Chi-beria a reality. Again.
• Another indoor “easy to take care of tree” under loving care by a good friend of mine inexplicably bites the dust in New Hampshire. Again.
• Currently in Maine, I sigh loudly as I break out the snow shovel. Again.

As you may have noticed, I’ve an interest in the science of longevity.  For example, how tennis is the sport associated with longevity on a clinical and arguably molecular level.  And while New Englanders do attempt indoor play once winter has come, dag blast it, the cold and absence of sunlight still gets to the majority of the populace around this time.

This begs a question debated since the time of grandparents who love saying things like this.  So. Does science say cold weather is detrimental to your health?  Or are northern folk a healthier breed, akin to the toughened Night’s Watch stationed at Castle Black or perhaps hardier still the Freefolk that were born and still live beyond The Wall?

The Study

Hailing from two of the most idyllic places to research such a question, Kue Young, a former Dean of the University of Alberta School of Public Health teamed up with Tiina Maria Ikäheimo (formerly Mäkinen), a now adjunct Professor from the University of Oulu Center for Environmental and Respiratory Health Research in Finland (read: both are located beyond The Wall) and produced an answer derived from studying human populations living in Arctic regions. Unfortunately, the answer was not reassuring for northerners.

Ask any northerner, and they can easily rattle off many practical reasons that winter seasons are hazardous for humans. What Young and Ikäheimo found was that the temperature itself was a serious public health hazard – of even greater concern with global climates shifting. To arrive at this conclusion, they examined 27 Arctic region populations including some in Alaska, Canada, the Nordic countries and the Russian Federation.

First, they established mean temperatures for each region based on weather station data taken between 1961 and 1990, as seen in the table below. Alaska for instance posts a positively balmy -10.9 C (12.4 F) mean in January and 14.1 C (57.4 F) in July. But, things can always be worse. The Sakha Republic (part of the Far Eastern Federal District of the Russian Federation) sees a -37.9 C (-36.2 F) mean in January and a swimsuit ready 16.5 C (61.7 F) mean in July. For comparison, peruse a list of mean temperatures for various U.S. cities in January here.

After statistical correction for confounding factors like socio-economic status, access to healthcare, population density and education, the primary finding was that lower temperature was independently associated with lower life expectancy in both men and women.  To top it all off, there were higher infant mortality rates and higher mortality rates from respiratory diseases with lower temperatures.

“For every 10°C increase in mean January temperature, the life expectancy at birth among males increased by about 6 years and infant mortality rate decreased by about 4 deaths/1,000 live births.”

Young and Makinen. Am J Hum Biol. 2010 Jan-Feb;22(1):129-33. doi: 10.1002/ajhb.20968.

For comparison, the total U.S. 2016 infant mortality rate was 5.9 per 1000 live births. The table of life expectancies seen in the regions of study follow:

Mildly concerning.

Per reports, only the fact that they did not have access to and were unable to analyze other health information – e.g. smoking status, weight, sunlight exposure, active versus sedentary lifestyle – partially alleviated my selfish concerns about my own longevity as an individual living mere minutes from The Wall.

Packing for the south, as I press publish.

But wait. This can only mean that warmer, equatorial weather is the key to longevity and all else that ails in this study…right?

Tune in next time, as I research and write from more southerly climes on that question.

Miscellany

• Game of Thrones fans quickly recognize the phrase “The North remembers.” The interpretation is that the people of The North Kingdom seldom forgot betrayals. Interestingly, there are numerous studies stating cold weather can cause cognitive impairment, and hence memory problems. But, admittedly this is an area of current academic debate so the jury is still out on whether The North remembers.
• All this cold talk reminds me of Ulaanbaatar, capital of Mongolia -24.6 C mean (-12.3 F) in January. Mongolia currently reminds me of The HU and Wolf Totem – a guttural song befitting that of even the Freefolk.