Peroxide is also ineffective in preventing halitosis. Peroxides are oxygenating agents which can produce harmful free radicals and have been of concern to some health professionals when used for long periods of time in the presence of chronic inflamed tissue. Gum tissues are usually chronically inflamed and therefore are susceptible to negative effects of peroxides which can cause adverse cell changes to occur. Unfortunately, almost all major toothpaste and mouthwash makers are jumping on the misguided baking soda and peroxide band wagon. Alcohols can be harmful and I strongly urge consumers to stay away from them.
Smoking too can make bad breath worse.
Smoking and chewing tobacco dry out the mouth and again produce adverse tissue dryness and plasma secretions which are broken down by bacteria into volatile organic compounds. Anything which dries the mouth can promote bad breath, including some prescription drugs, alcohol consumption and some systemic diseases. Dry mouth can be caused by sinus congestion and nasal blockages. Rhinitus and nasal drainage also cause bad breath. Even dieting and diabetes can cause odor.