To many of us, the health advantages of winter are obvious. No mosquitos. No snakes. No limb-threatening encounters with rogue lawnmowers or weed whackers. But the cold season has its own set of perils. In addition to the obvious slippery surface issues that yield falls and car accidents, statistics show a marked increase in the likelihood of death due to cardiac problems! Studies reveal  that  more heart attacks occur during the winter than any other season—in the Northern Hemisphere you are twice as likely to have one in January than in July. Why that is so, and what a person can do to avoid winter heart attacks, is an important health issue.

One reason more heart attacks occur in the winter is due to the effect of cold weather on circulation. It takes more energy to keep the body warm when the air is chilly, and pumping more warm fluid (in this case, blood) is the main mechanism for keeping tissues in the right temperature range. Thus, the circulatory pump, the heart, has to work harder. Unfortunately, though, just when the body needs more circulation, the cold external temps also prompt a reflexive tightening, or constriction, of the blood vessels. Blood flow becomes more difficult. This cold-induced reduction in artery flexibility, combined with the increased amount of blood being pumped, results in a marked rise in blood pressure.  And as we know, high blood pressure makes heart attacks more likely. This explains, in part, why heart attacks are more common in the winter.

Another aspect of winter that endangers the heart is felt to be attributable to vitamin D deficiency.  Vitamin D is naturally synthesized in a person’s skin when that skin is exposed to the sun’s ultraviolet (UVB) rays. In winter months a person’s vitamin D level falls due to the reduced intensity of sunlight.  Scientists have found an increased mortality rate associated with low vitamin D and are working to explain it. One compelling study compared winter heart attack rates of similar populations that differed only in the altitude of their communities. Fascinatingly, while average temperatures in the high elevation villages were much colder, the mountain inhabitants had a lower – not higher – rate of heart attacks compared to the flatlanders. This reduced heart attack rate correlated with higher average vitamin D levels found in those high altitude dwellers .The sun’s rays are stronger at higher elevations, allowing increased production of “D”.  Taking vitamin D, therefore, may theoretically reverse one component of winter’s negative health impact.

Also adding to the winter heart attack risk are the “sudden surge” types of activities that are common to this season. The number one dangerous activity is snow shoveling.  It is estimated that the average full snow shovel weighs over 16 pounds, and repetitive lifting is a marked work-burden on your heart.  Combining this stressful type of exercise with blood pressure that is already elevated due to cold temperatures creates a very perilous situation for the heart.

There is one other factor that is felt to contribute to the heart attack tendency in the winter. Cortisol is a hormone in your body that varies based on the day/night cycle. High cortisol levels raise blood pressure and increase the tendency of blood to clot. Cortisol levels are highest in the morning, so it is not surprising that heart attacks in any season occur more frequently in the morning! And surveys reveal that the tough outdoor chores of winter—like snow shoveling—are more often done early in the day.   Thus evolves a treacherous scenario: waking  up early to clear paths and driveway, perhaps tossing down a cup of coffee beforehand to try and pep yourself up (warning—caffeine increases blood pressure too!) , then venturing  into the cold to do heavy lifting….it is a recipe for cardiac disaster.

So what can a person do to prevent winter heart attacks? First, understand your baseline cardiac status.  If your doctor feels you are already at risk for heart problems, you should give serious consideration to never snow shoveling and to sharply curtailing your time outside during the real cold periods. For the rest, a simple strategy can save lives. First, acknowledge and respect the stress that cold temperatures place on the heart. Dress warmly and remember that covering the head and face greatly reduces heat loss from the body. This simple technique dramatically decreases the cardiac strain associated with efforts to keep warm! And try to do arduous outdoor work later in the day so as to avoid exertion during the high-cortisol am hours. When shoveling snow or participating in other strenuous outdoor winter activities, be sure to take a break every 15 minutes or so–and don’t load up on caffeine or nicotine then!  Lastly, consider taking a vitamin D supplement. Your doctor can determine your exact need.

Yes, the livin’ is easy in the winter: no poison ivy, no sunburn.  But the season presents multiple dangers to your heart and it is urged that you take steps to reduce your risk of cold weather heart attack.

Submitted exclusively to Pawling Public Radio