Why some people always have a runny nose while others don't

London, Oct 13 (ANI): Ever noticed how some people always seem to falling prey to cold, be it summers or winters? It may be genetic, and now a leading science writer, Jennifer Ackerman, busts some other common myths about cold in her book 'Ah-Choo'.

Vitamin C won't stop a cold: Studies have shown that there's no evidence that vitamin C prevents cold. The only time it might help is if you're engaged in extreme physical exercise or exposed to extreme physical cold, reports the Daily Mail.

You can't catch a cold by kissing: a kiss won't give you a cold. The largest family of viruses causing colds are rhinoviruses, and these rarely enter our bodies through the mouth, according to research at the University of Wisconsin Medical School.

Estimates suggest that it takes as much as 8,000 times as much virus to cause infection by way of saliva than by other routes. So kissing or sharing drinks is unlikely to spread a rhinovirus.

Green mucus isn't a sign of bacterial infection: green mucus is not a sign of bacterial infection, but a sign the immune system is working properly.

As the body recruits more and more virus-fighting white blood cells to the nose, the colour of the mucus changes from clear to yellow to green. The greener the colour the more robust the immune response.

Blowing your nose hard doesn't help: The stuffy, blocked feeling that stifles breathing during a cold is not the product of excess mucus, but swelling blood vessels in the nasal passages. But colds exaggerate the asymmetry of rhythm - completely closing one nasal passage. So the urge to blow forcefully is increased, though it doesn't relieve the stuffy feeling.

Chicken soup really helps: Touted as a cold remedy by grandmothers since time immemorial, recent research shows there may be some scientific fact behind the legend that chicken soup helps a cold.

Drinking fluids makes little difference: there are no controlled clinical studies showing any benefit of maintaining steady fluid intake during a cold. (ANI)