My white hair is getting more and more. US President Barack Obama has more and more white hair. You always complain that we China people are not innovative, so we just copy. Americans are better at copying, aren't they? Even the president copied the white-haired king of China! Therefore, plagiarism is not important. The important thing is why Obama and I have turned white! Recently, some media raised this question to Obama. Obama's children's shoes said that Lao Yang's hair turned white, and he didn't know why, but his old man's hair changed color because of genes, not because of work pressure. Obama said: "When my grandfather was 29 years old, his hair began to turn white, so I think my stage is coming. It just happened to coincide with my term of office. " It sounds like being cool, but biologists say that Obama's statement basically reflects the fact that heredity is the main factor that determines whether hair turns white. In fact, the 50-year-old President Obama's genes are very typical: a commentary published in the journal Dermatology Research in 2005 pointed out that white people's hair began to turn white between the ages of 35 and 36, Asians were in their forties, and Africans were in their forties. Obama's mother is white and his father is African, so it is normal for him to start to have white hair in his early 40 s. However, experts have different views on whether stress will have a negative impact on his hair. Although there are still some ambiguities in hair whitening, the basic theory of hair whitening is very clear. With the aging of hair follicles that promote hair growth, hair will gradually turn white and become "abnormal". In a person's life, hair follicles go through 10 to 30 growth cycles. At each later stage, hair follicles produce less enzymes, which are called contact enzymes. Contact with enzymes is very important because it decomposes another chemical naturally produced by cells in hair follicles-hydrogen peroxide, which is the same substance used by "pretending to be a blonde" to lighten hair color. Because the elderly have less contact enzymes to decompose hydrogen peroxide, too much hydrogen peroxide in each hair follicle will make the hair turn white. According to Gerald weissman, editor-in-chief of the Journal of the Federation of American Societies for Experimental Biology, their magazine has published many papers that stress will accelerate the process of hair follicle aging. But he added: "Look at the hair of young people in Egypt or Libya, or the hair of young soldiers in Israel. Although under great pressure, these young people have no white hair. I think it is genes that cause hair to turn white. " However, not everyone agrees with weismann. Andel King-Slominsky, a dermatologist at the University of Tennessee Health Science Center, agrees that genes have the greatest impact on hair follicle aging, but he says there is "strong evidence" that environmental factors such as stress also have an impact. Slominsky said: "Stress is related to hair turning white. This phenomenon was particularly described during World War II, when many soldiers suddenly turned white or turned white overnight. " Slominsky said that although this anecdotal evidence shows that stress does cause hair to turn white, "the mechanism of this phenomenon is still unclear", and this process may be different from that caused by age. Ralph Bao Si of the University of Lü beck believes that stress hormones may lead to the production of free radicals, which will destroy melanocytes (cells that produce pigments in hair follicles and make hair appear black). As we all know, stress can affect other physical processes, such as suppressing the immune system, causing digestive problems and raising blood pressure. Bao Si and other scientists are currently studying how it affects hair follicles. (Yang Xiaowen)