Though greying of hair is a natural process, it could sometimes be due to medical conditions like a vitamin B-12 deficiency, anemia, vitiligo or issues with the pituitary or thyroid gland. There is a proven correlation between going grey and smoking, according to studies.
One such study found that smokers are two and a half times more likely to go grey early as compared to non-smokers. Smoking is also said to be related to baldness because of the chemicals present in cigarette smoke damage hair and cause hair cells to break down, as stated by The New York Times.
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