It's best to steer clear of secondhand smoke altogether whenever possible; studies done by American Society of Heating, Refrigerating and Air-Conditioning Engineers have found that ventilation does not necessarily reduce the dangers of secondhand smoke exposure.
Another thing our tweeters have an aversion to is milk. They avoid it for fear it will gunk up the works.
Studies find that dairy does not increase the flow of phlegm. Eliaz said foods such as yogurt and fermented milk, which contain probiotic bacteria, can turbo-charge the immune system's response to the flu virus, possibly decreasing the frequency and intensity of illness.
A 2011 Cochrane review of 10 studies found probiotics to be a superior cold and flu fighter compared to a placebo or no treatment in both adults and children. They found that taking probiotics could help reduce the number of upper respiratory tract infections by 12 percent.