What is the cause of dandruff in hair?

Dandruff, which about half of humanity suffers from the first identifiable example of his problem is 125 million years old.
it's based on a fossil. What remains today on China's borders the first specimens of Bran in history were discovered in 2018 in fossils left over from a dinosaur, a species of Microraptor (crow-sized and able to glide through the air) that lived in an area.

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The one who has inhabited our scalp since our infancy Malassezia fungi proteins and fats in our skin it feeds on. These fungi especially prefer our scalp the reason for this is that fatty sebum secretion is abundant in the follicles where our hair roots are located.
Malassezia fungi break down fat in the sebum with lipase enzymes that they produce. But because they can only consume saturated fatty acids of a proper structure, they are extra unsaturated in twisted structure due to carbon bonds they leave fatty acids as waste. In some people, these fat residues that are stuck in the scalp activate the body's defense mechanism. Under Normal circumstances, it is the top layer of our skin dry and relatively hard Dead Cells in the epidermis are approximately
in a month's time, it is removed from the skin under the influence of newer cells from the bottom. In the usual process this spills the pieces are too small to be seen by the eye. But this cycle speeds up to a week when the defense mechanism is activated due to fungal residues he could fall.
At this rate, the cells in the upper skin are masses of hundreds of cells, as the conditions under which they will shed individually do not occur Bran grains of the size visible to the eye creates