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Though it first appeared last spring, it wasn’t until winter arrived that the H1N1 flu started hitting large portions of the population.
Why does this virus prefer cold conditions to spread itself around?
In North America, flu season takes place every year around the winter solstice, from the end of November to the beginning of March.
It was assumed for a long time that transmission of the flu was made easier during the winter because people stayed inside more. This, however, is unlikely because most of us are in close contact with people throughout the year, whether that is on the bus, at school or at work, without contracting the virus.
Today, the reasoning is that that winter weather conditions have some effect on the contagious properties of the virus. In 2007, scientists infected guinea pigs with the influenza virus (H3N2) and examined the impact of temperature on the virus’ transmission rate. They found that when the animals were placed in a temperature of 5 C, the virus jumped quickly from animal to animal. However, there was no transmission of the virus when the animals were subjected to a temperature of 35 C
The transmission rate had nothing to do with the immunity of the animals subjected to cold, but rather a marked increase in the time the animals were secreting viral particles when in a colder temperature. In fact, the researchers found that the animals in the cold secreted the virus for 40 hours longer than they did in warmer temperatures.
The amount of humidity also appeared to play a significant role in the transmission of the virus; the transmission rate rose in 20% humidity but was practically non-existent in more humid conditions. Long story short, the influenza virus is quite simply more contagious at lower temperatures and low humidity, two weather conditions present during the winter.
In addition to aiding the transmission of the virus, it is also possible that the winter conditions can be favourable to the infection by affecting the immune system. For example, it is well known that the lower amounts of sunlight during winter months can cause a marked decrease in Vitamin D absorption.
This vitamin has multiple positive effects on the immune system, notably the vitamin’s ability to stimulate the production of antimicrobial peptides by the immune system cells that line the walls of the respiratory system.
The importance of Vitamin D was made more obvious when it was suggested that children with low levels (<10 ng/ml) were 10 times more at risk of pulmonary infections. It seems our grandmothers weren’t out of their minds when they made their kids consume cod liver oil, one of the best sources of Vitamin D, come winter time!
BASE PRECAUTIONS
While the current H1N1 strain seems to be very contagious, most who come down with it show only mild flu symptoms. Still, it is important to take a certain number of precautions if you want to avoid getting the virus.
• For people in the higher risk groups (young children, people with health problems, pregnant women), the H1N1 vaccination remains the best way to protect against the virus.
• For people in good health that don’t want to get vaccinated (or those who want to but can’t get it for several weeks), there are still a number of ways to improve the efficiency of your immune system:
• Eat well. What we eat can have a huge impact on the way our immune system cells function. A diet rich in vegetables and containing items known for their immune system benefits (algae, mushrooms, probiotics) can go a long way in protecting yourself. And because foods rich in Vitamin D are rare, a 1,000 UI (or 400 UI for children) is recommended.
• Sleep well. Many studies have shown that a lack of sleep hurts immunity to some illnesses.
• Keep moving. Active people are generally less affected by the flu than those that are sedentary.
• Stay clean. Regular hand washing and the disinfecting of objects touched regularly (phones, computer keyboards, etc.) remains the best first line of defence against infections.
ANTI-CANCER RECIPE: MISO SOUP
Miso is a fermented soy paste rich in isoflavones. There are many different qualities of miso and they come in white or red. In Japan, this low-calorie soup is consumed morning, noon or night. Miso can be stored for at least one year in a fresh, dry place.
Gai Lan has been nicknamed “Chinese broccoli” even though it is not actually part of the broccoli family. Its long leafs are a dark green and the stems are very thin.