Gray Hair Can Return to Its Original Color

Few signs of old age are clearer than the sight of gray hair.     1     we grow older, our strands of hair lose their youthful color. Although this may seem like a permanent change, new research reveals that gray hairs     2     miraculously regain color — at least temporarily.

In one 1972 paper, the late doctor Stanley Comaish reported an isolated case of a 38-year-old man, with his three strands     3    (be) light near the ends but dark near the roots. This signaled a reversal in the normal graying process,     4     begins at the root.

A new study from researchers at Columbia University is the first     5    (offer) quantitative evidence linking psychological stress to graying hair in people. Having analyzed individual hairs from 14 volunteers, researchers compared the results with each volunteer’s stress diary, in which individuals’ review of their calendars and each week’s level of stress rated are included.

When hairs were aligned with (与……对照) stress diaries, striking associations between stress and hair graying     6    (reveal) and, in some cases, there was a reversal of graying when stress was removed. There was one individual who went on a long vacation, and five hairs on that person’s head returned back to dark during the vacation.

Although it may seem easy to understand     7     stress can speed up graying, the researchers were surprised to discover that hair color can be restored when stress is eased. We could picture hair as a powerful tool to assess the effects of     8    (early) life events on aging — because hair provides a kind of physical record of past events, much    9     the rings of a tree. It’s pretty clear that the hair encodes part of your biological history in some way. Hair grows out of the body, and then it crystallizes into     10     hard and stable that holds the memory of your past.

Three Myths About Skin

We put importance into caring for skin since it’s the first thing other people see. Skin might be one of the least correctly     1     (interpret) parts of our bodies. So today, I’d like to run through three myths we have about skin.

Myth No. 1: Healthy skin is skin that looks perfect. When we talk of healthy skin, we     2     think of a clear and smooth surface. But skin is a living organ,     3     heart or lungs and any other complex organ, serving many functions, not just about what’s going on at the surface.

Myth No. 2: You only need sunscreen on sunny days. UV rays from the sun are so strong that     4     damage our cells’ DNA. There are two types that affect the skin. UVA rays damage protein in skin, quickening the pace of aging. UVB rays, meanwhile, cook the outer layer of the skin, causing sunburn.     5     our cells can repair that damage to some extent, it accumulates over time, and can lead to skin cancer. When our skin     6     (expose) to UV rays, it gets darker, which is the way of showing it’s been damaged. So by wearing sunscreen, even when it’s cloudy, you are protecting yourself from sunburn, early aging and skin cancer.

Myth No. 3: You can shrink pores. Pores are the tiny openings in our skin. They’re     7     let sweat cool you and oil smooth skin. Pore size is largely determined by genes,     8     function is to carry information for particular characteristics, and rarely changes. In other words, pores don’t really shrink. So stop     9     (spend) your money on pore minimizers and just wash your face with the products basically made from stuff that won’t block pores.

Our skin is     10     amazing organ, so let’s treat it right and forget about those myths, OK?

5 . Who is to blame for the shapes of our noses?

If you are not satisfied with the shape of your nose, blame it on climate, not your parents or grandparents. In a study published this week in the journal PLOS Genetics, researchers from the Pennsylvania State University found that human noses may have been shaped, in part, by a long process of adaptation to local climate conditions.     1    .

The findings were based on an examination of the size and shape of noses on people with West African, South Asian, East Asian, or Northern European ancestry. It showed that the width of the nostrils is strongly related to temperature and absolute humidity (绝对湿度), but not the result of genetic drift (遗传漂变).

One purpose of the nose is to condition the air we breathe, to ensure that it is warm and moist when it reaches the lungs, which helps to prevent infections.     2    which was probably more essential to have this trait in cold and dry climates, it said.

People with narrower nostrils probably had better and had more offspring than people with wider nostrils, in colder climates.    3    . The nose has had a complex evolutionary history, however, and researchers suspected that additional factors, such as cultural preferences when picking a mate, have also pl played a role in shaping the nose.     4    . Studies of human adaptation are essential to our understanding of disease and yield insights into why certain conditions, such as skin cancer, are more common in certain populations.

The researchers said that it may be worth investigating whether the shape of the nose impacts ones risk of contracting breathing diseases when living in a climate that is different from one's ancestors.

Not everyone is born with beautiful hair, but by learning a few hair care facts, you can make your hair look its best. Healthy, attractive hair should     1    . Whether your hair is long or short, light or dark, it should look smooth, silky and     2    . Everyday events such as shampooing, brushing and blow     3     can do great damage to your hair, causing the dry, brittle and frizzy appearance.

When you     4     your hair, you should use a shampoo for your specific type of hair. If you have permed [烫(发)] or color treated hair, you should use a shampoo for chemically treated hair. Many people believe that baby shampoo is very gentle and safe to use on their hair. This is a wrong idea. Leave the baby shampoo for your baby. If you are not sure what your hair type is or what type of shampoo to use, ask your     5    . Your hairdresser can recommend a specific shampoo and     6     to keep your hair healthy and shiny.

Brushing your hair can actually help improve the shine. You should never brush wet hair. When hair is wet it is much weaker than when it is dry. Wet hair will break very easily if it is not combed very gently. Never     7     your hair between the towel to dry it, for this can cause severe breakage. Before combing, a leave-in conditioner should be sprayed on the hair to help restore shine and help remove tangles. Using a wide tooth comb,     8     hair from the ends and work your way up.

Blow     9     are very convenient and many of us use them daily. If they are used incorrectly, they can cause severe heat damage to your hair. You should allow your hair to air dry until it is about half way dry. If you follow these healthy hair practices, you should notice an improvement in the condition of your hair within two to four weeks, depending on how       10     your hair is.