Remember when you were growing up and your mom always told you to wear a coat when you went outside during the winter so you wouldn't catch cold? It turns out that you can't actually catch cold from cold weather. This was actually scientifically proven back in 1958 and the results were published in "American Journal of Hygiene" by researcher H. F. Dowling. He subjected 400 volunteers to viruses that cause colds in different temperature environments. Some wore heavy coats while some wore only their underwear. Some volunteers were in 80 degree temperatures while others were exposed at 60 degrees. All the groups, regardless of temperature or amount of clothing, had the same level of infection.

The bottom line is that you can't actually catch cold from cold temperatures. You do catch cold whenever your immune system is not operating at its peak. According the "Natural Science Daily" it's your cells that catch the cold first, and that happens when the cold virus binds to a cell. Once a cell becomes infected the virus can spread by reproducing itself and infecting other cells. Voila! You've caught cold.

So how do you not catch cold this winter? You have to boost your immune system in two ways. First you have to increase your body's awareness that viruses are in your system so that it can produce an immune response. According to biologist Paul Freimuth, it often takes time for your body to stage this immune response. This delay can mean the difference between catching a cold and being healthy, so increased awareness of viral invaders is crucial. Second, you need to support your body's immune response by providing nutrition it needs. Here's how to do both.

** Increase Your Body's Awareness **

A primary way your body knows that invaders like viruses and bacteria are present is through macrophages. Macrophages are a type of white blood cell and they circulate throughout the body and engulf and digest foreign invaders. They also play a pivotal role in coordinating the immune system's arsenal of defenses. But for macrophages to work they have to get moving and circulate through your body.

Scientific research shows that certain substances stimulate your body's macrophages. Key among them is a substance found in brewer's yeast: beta 1,3 glucan. Beta 1,3 glucan is a specially extracted ingredient of brewer's yeast and is not the same as taking brewer's yeast, which will not give you the same results. Beta 1,3 glucan, taken orally, stimulates your body's innate immune system to, among other things, produce white blood cells, mobilize cells to "recognize" foreign invaders, and produce anti-microbial agents. Still think you'll catch cold with all this activity going on?

** Support Your Immune Response **

Once your body is aware that foreign invaders are present, you need to support the immune response that follow or you'll still catch cold. To support your immune response you need to focus on your natural killer (NK) cells. According to a paper published in "The Journal of the American Nutraceutical Association," NK cells play an important role in neutralizing foreign invaders, including pathogenic bacteria, viruses, parasites, and diseased cells in the blood, lymph, tissues, and organs of the human body. When NK cells come in contact with these foreign bodies, they secrete biochemicals that neutralize them. That is, of course, why they are called natural killer cells. Scientific research shows that natural foods and herbs such as blue-green algae, astragalus root, and ginseng all support and boost the activity of NK cells. All of these substances are easy to obtain, if not locally, at least on the internet.

When it's cold out you won't ever have to worry that you'll catch cold from the cold, but you do need to focus on supporting your immune system throughout the year. Luckily, you can do it easily by just adding the natural ingredients discussed in this article to your regular nutritional regimen.