Is cutting hair short really beneficial to the health of hair? What is the scientific basis?

The health of hair roots determines the quality of hair, because hair grows from hair roots, and absorbs rich nutrients during the growth period to make hair grow. If the nutrient absorption is unbalanced, the hair quality will naturally be affected. Hair that has been outside the scalp, after growing from the scalp, has been hurt by the outside world, such as sun exposure, wind blowing and frequent dyeing. The longer the hair, the more trauma. Compared with long hair, short hair is often trimmed, severely damaged "old" hair is trimmed, and because it is "short", the hair that enters people's field of vision is only "fresh" hair that exceeds several parts of the hair root. Therefore, the hair quality of short hair is better than that of long hair, but it should be noted that if the hair roots are not healthy enough, even if the hair is cut short, it will still be short-tempered, dry, weak and even lose hair. These are the answers I got from Shi Yunxun's consulting experts in specialty store. I hope I can help you.