When scientists at the University of Kanazawa in Japan investigated the effects of radiation and other chemicals on the fur of mice, they found that their clothes were discolored over time. This is because the cells in their hair are forced to mature, reducing the production of melanin and the chemical that gives hair and skin color.
Premature graying of hair, also known as poliosis, is the appearance of gray hair before the age of 30. It is a common condition that affects about 20% of the population. The exact cause of premature graying is not known, but it is thought to be due to a combination of genetics and environment. But Dr David Fisher, head of the department of dermatology at Harvard Medical School,
said that preventing these cells, which have damaged DNA, to divide is beneficial. This can prevent you from developing a tumor, which is a ball of damaged cells that grows out of control. “Graying may be a protective mechanism,” Dr. Fisher told Bloomberg. They showed that this process removes damaged cells. “The good news is that if you’re going gray, it’s best if the cells don’t stop.”
He said that the findings, reported in the journal Cell, have “great implications” as they suggest that maturation and differentiation into other cell groups can also help prevent cancer. Stem cells are the lifeblood of the body, allowing them to copy themselves which can be different from other types of cells. When the mice’s hair follicles stopped growing,
the animals rapidly depleted the pigment-producing cells in their hair. Dr. Fisher spoke about the findings of Dr. Emi Nishimura of Kanazawa University in Japan, who worked with them at Harvard did. Dr. Nishimura has discovered stem cells in hair and shown that their exhaustion during aging causes gray hair. For this study,
his team exposed mice to radiation and drugs used in chemotherapy, and analyzed changes in their fur color and their stem cell levels. Looking at the hair under the microscope, they saw when the stem cells changed into other types of cells and linked the change to gray hair.
A similar mechanism may work in humans, he says. The research challenges current ideas about how the body tries to protect itself when it experiences genetic damage from radiation or other toxins, Dr Nishimura said. People have thought that cells die when their DNA is damaged through apoptosis, the scientific term for cell suicide, Dr Nishimura said. Some of the factors that can cause premature gray hair include:
