Some African Americans appear to have a genetic vulnerability to the harmful chemicals in cigarette smoke

Possible triggers for canker sores include: A minor injury to your mouth from dental work, overzealous brushing, sports mishaps or an accidental cheek bite Toothpastes and mouth rinses containing sodium lauryl sulfate Food sensitivities, particularly to chocolate, coffee, strawberries, eggs, nuts, cheese, and spicy or acidic foods A diet lacking in vitamin B-12, zinc, folate (folic acid) or iron An allergic response to certain bacteria in your mouth Helicobacter pylori, the same bacteria that cause peptic ulcers Hormonal shifts during menstruation Emotional stress Canker sores may also occur because of certain conditions and diseases, such as: Celiac disease, a serious intestinal disorder caused by a sensitivity to gluten, a protein found in most grains Inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis Behcet's disease, a rare disorder that causes inflammation throughout the body, including the mouth A faulty immune system that attacks healthy cells in your mouth instead of pathogens, such as viruses and bacteria HIV/AIDS, which suppresses the immune system Unlike cold sores, canker sores are not associated with herpes virus infections

Ratajczak A, Jankowski P, Strus P, Feleszko W
The negative effects of nicotine on reproductive systems are also well documented for both male and female subjects