By michael - February, 19th 2014

The importance of the immune system is underlined by the example of people who have been born with problems with their immune system (this can mean that it doesn't work at all, or that only parts of it work) – a condition called ‘immunodeficiency'. Such individuals can become infected extremely easily, and the results can be fatal – this can mean living in a sterile environment, with only limited contact with people. Thankfully, many individuals can be helped with a bone marrow transplant that allows them to develop a working immune system (the bone marrow is the source for all of our immune cells) – however, this still depends on finding a suitable donor. There are other approaches being perfected however, such as replacing ‘faulty' genes with working ones to correct the problem.

Some people seem to survive cold and flu season with nary a sniffle. And yet plenty others seem to catch cold after cold; sidelined with a perpetually stuffed-up nose and hacking cough that lasts all winter. So what's different between these two groups? Research shows your cold and flu vulnerability may come down to a few important—and unexpected—habits, like how much sugar you eat or how dry your nose is.

You have a sweet tooth

Eating too much sugar doesn't just pack on pounds. A study published in the American Journal of Clinical Nutrition found that eating 100 g of sugar (think three cans of soda) significantly hampered the ability of white blood cells to kill bacteria for up to 5 hours afterward.

You don't drink enough

There's a reason moms and doctors always push fluids on you when you're sick. Your body needs plenty of water to flush out toxins—and yes, coffee …

You may pay more attention to the health of your immune system during the winter, when colds and flu surround you. But the truth is, your immune system has to work hard all through the year, whether it’s offering protection from a flu virus or an infection that could happen any time.

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