Darkened lips are quite a common occurrence in many people, especially after a certain age. It is worth noting that smoking does not really have a direct impact on the color of the lips like most people actually believe. This is because the only way that the lips can be affected by smoking is the years of hypoxia. However, since you did mention that you were a smoker, this is not something that you need to worry about. The skin on the lips, as you would have noticed, is a little different from the rest of the skin on our body. Fundamentally, it is a lot thinner and doesn’t have the hard kertinocyte layer that our normal skin has.
The layer of keratinocytes is the layer of the skin that is responsible for waterproofing the body. Additionally, the keratinocyte layer also protects the skin from continuous pressure and friction damage by forming additional layers that will form a callus. When it comes to the color of the lips there is another bunch of cells apart from the keratinocytes, called the melanocytes. Melanocytes create a substance called melanin that is the human skin pigment. More or less of this pigment are responsible for the different skin colors that human beings display. When there are very few melanocytes in the lips, as is the case in Caucasians, the lips naturally appear to be pink; whereas, when there are more melanocytes, they appear brown. What takes this equation to the next level is the amount of sunlight that one is exposed to in a lifetime. When the ultraviolet rays of the sun come into contact with the melanin in the skin and lips, the melanin darkens because of a chemical reaction called oxidative stress. This is an incomplete oxidizing reaction that leaves the melanin a shade darker. Repeated exposures keep darkening the melanin till they appear black.
Reversing this effect requires a bleaching. This can be done by simply taking some strawberry and lemon juice mixed pulp and applying to your lips every day. Allow the pulp to dry on your lips and avoid licking them while this is underway; this mix of ingredients work because of the presence of vitamin C that can reverse the effects of oxidative stress. Vitamin C is an antioxidant and therefore perfect for the task at hand. You should also increase the amount of azelaic acid that you consume by having more bran, wheat, and rye in your diet.
answered by G M