It is easy to think that smoking might contribute to health problems anywhere in the body--but hair dye? A recent U.K. study published in Gut journal questioned over 4,500 people about their health habits and genetic tendencies to determine if environmental factors were linked to an increase of liver disease. The results showed that a history of smoking occurred in 67 percent of those diagnosed with a form of liver disease called primary biliary cirrhosis (PBC) and hair dye was used by 37 percent of women with the disease.
Primary biliary cirrhosis (PBC) is a chronic disease where the bile ducts in the liver become damaged and are no longer are able to effectively pass digestive enzymes to the GI tract. These enzymes, in the form of bile, are what allow us to metabolize fat. The bile then becomes trapped in the liver leading to cirrhosis or scar tissue. If the cirrhosis progresses, the liver fails to function properly and fatal complications may occur.
The cause of PBC is unclear. It is thought that family history or an autoimmune disease trigger may be involved. This study attempted to look at whether environmental factors play a role. Three different groups of people were given questionnaires regarding their own environmental practices of smoking, drinking, use of hair dye as well as other medical illnesses and genetic tendencies.
The study showed that people with PCP were more likely to be smokers and have started smoking before developing PCP. Women who had PCP used hair dye more often than women in the control group. It is unclear why hair dye might be a contributor. Some theorize that the chemicals in hair dye may be related other cosmetic chemicals, especially octynoic acid, which is in both hair dye and nail polish.
Other results from the study showed that autoimmune diseases such as rheumatoid arthritis and thyroid disease or a family history of another autoimmune diseases occurred more often in PCP patients. Skin diseases such as psoriasis or shingles were more common in those with PCP as well as it being more prevalent in those with frequent urinary tract infections.
The study has its limitations.