For generations, myths have grown up around the body’s shape, size and color, suggesting these factors can explain whether you will be prone to physical diseases – or even mental illness.
Now, scientists are beginning to examine these superstitions – revealing at last the true secrets of the body.
Read our guide below to the truth behind some well-known body myths.
MYTH: HAIR COLOR INFLUENCES YOUR HEALTH
Fact: All hair is made of compacted protein called keratin, which grows – on average – about 5mm a week. But some hair coloring can actually have benefits to your health.
Redheads seem to have a secret genetic weapon, since scientists have discovered that red hair and a pale complexion permit more sunlight into the skin, where it encourages the production of vitamin D.
A deficiency in this vitamin means weaker bones, and, in adequate amounts, it helps to prevent the lung disease tuberculosis, which can be fatal.
The color of your hair also influences how well the head is insulated. Redheads have the least strands – at around 80,000 – while blondes have the most – at around 120,000. Blonde hair is also thinner than red or brunette, which also accounts for the greater number of strands.
A strand of hair grows for a year before it falls out and is replaced by another. You will grow an average of 590 miles of hair in a lifetime.
Different races have different types of hair growth. Those with Negroid genes will usually have curly hair, while pale complexions have coarse, straight hair. These differences are caused, in part, by the shape and size of the hair shaft and hair follicle.
MYTH: BLUE EYES ARE WEAKER THAN BROWN
Fact: Eye color is determined by the presence of the pigment melanin, which also protects the macula lutea part of the eye – responsible for detailed vision – by trapping light rays and preventing damage.
The darker the eye, the more melanin in the iris, which is why those with pale-colored eyes are more sensitive to sunlight. People with light-colored eyes are more vulnerable to macular damage, such as cataracts or loss of vision.
Scientists at Southampton University found that people with dark-colored eyes are less likely to go deaf if they get meningitis, suggesting the more pigmentation, the better the inner ear is protected.
MYTH: YOUR NOSE CAN KEEP YOU WARM
Fact: In its basic form, the shape of the nose is influenced by the position of the teeth. Broad teeth create a broader nose and small front teeth create a narrow nose.
Nostrils that aren’t circular are more efficient warming and moistening air, which is why small noses are found in those who live in colder countries throughout the world.
Many Eskimos also have flat, padded faces, flattish noses and an extra fold of skin over their eyelids to help protect the face from the harsh environment. Large, circular nostrils warm and moisten air less, so they are found more often on people who live in hot, dry climates.
MYTH: LACK OF SLEEP CAUSES BAGS UNDER THE EYES
Fact: The eyelids are the thinnest, softest part of skin in the body and only 0.5mm thick. Fluid retention can cause puffiness because gravity draws fluid to pool in areas where skin is thin.
While lack of sleep is thought to be responsible for dark circles round the eyes, lying down causes the problem. However, sleeping propped on two pillows can drain the eye area. There are two fat pads on the upper eyelid and three on the lower, and under-eye bags are caused by fat accumulating in the area.
MYTH: LAUGHING GIVES YOU WRINKLES
Fact: Unlike the skin on your body,
which lies in sheets over muscles, facial skin is knitted to the structure beneath with fingers of muscle which protrude into the dermis (inner skin), giving the face its flexibility and allowing our expressions to change.
How the face creases is determined by genes and by habits you develop. Thus, people who laugh a lot develop ‘crow’s feet’.
As we age, the dermis loses its spring-back capacity and skin becomes less able to retain moisture.
MYTH: DARK SKIN WILL PROTECT YOU FROM THE SUN
Fact: Skin color depends primarily on a pigment called melanin, which helps protect the skin from ultraviolet light.
Black skin contains more melanin for greater sunscreen protection, which is why paler complexions are found in Northern Europe, where there is less exposure to the sun.
Though your skin color changes in the sun, your constitutive color is genetically determined without the effects of exposure.
There is an infinite number of different skin colors – phenotypes – the genes of melanin can produce, ranging from black skin to white.
Each expression of melanin has an accumulating effect on skin tone – the more there is in each parent’s genes, the darker that person will be. Other factors can darken skin, such as hormones in pregnancy.
Curiously, in white people, the darkest area of the body is the upper thigh and the lower back is the lightest. In black people the abdomen is the darkest.
MYTH: SHORT PEOPLE DON’T FEEL THE COLD
Fact: There is some sense in this claim: populations in cold regions of the world tend to be short and well-padded with fat to expose less surface area to the environment, which is why the Eskimos are not a tall race.
People who live in warmer climates tend to be taller and thinner because a greater surface area allows more heat to be dissipated.