Reader

23

Cracking your knuckles

will give you arthritis.

Myth! Recent studies haven’t found

a link between cracked joints and

arthritis. But some studies showed

that cracking your knuckles can

result in soft-tissue damage (which

can cause swelling) and a decrease

in handgrip strength.

24

You don’t need eight

glasses of water every day.

Truth! There’s no scientific evidence

that eight is the magic number. You

might need more or less than that,

depending on factors such as climate

and body size. To make sure you are

getting enough, just drink water

throughout the day.

25

Sitting up straight can be

bad for your back.

Truth! “Hunching can certainly be

bad for your back. But the opposite is

true, too,” says Neel Anand, MD, pro-

fessor of orthopedic surgery and

medical director of spine trauma sur-

gery at Cedars-Sinai Spine Center in

Los Angeles. “Sitting up straight for

too long without a break can also

cause strain.” When you’re sitting,

keep your lower back supported and

your legs uncrossed with your knees

at a 90-degree angle, and get up to

stretch every half hour or so.

26

People with dark skin

can’t get skin cancer.

Myth! Dark skin is less likely to burn,

but it isn’t immune to harmful

UV rays and the damage they cause.

People of all skin types need to use

sunscreen.

27

If you don’t have a

bull’s-eye rash, you

don’t have Lyme disease.

Myth! About 20 to 30 percent of

people with Lyme disease will never

develop that classic rash. Other

symptoms to watch for include fever,

headache, achy muscles, and swol-

len lymph nodes and joints.

28

You need less sleep

as you get older.

Myth! Older adults often sleep less

as a result of chronic conditions that

are more common with age as well

as the medications used to treat

them. But that doesn’t mean they

require less sleep. While sleep needs

vary from person to person, the CDC

recommends most adults get at least

seven hours of sleep for optimal

health.

29

Holding in a sneeze

is unhealthy.

Truth! As your body gets ready to

sneeze, pressure builds in your lungs.

When your body tries to push the

air out, it needs somewhere to go—

and if you’re pinching your nose and

mouth, it could be rerouted to the

ears. In rare cases, sending the

sneeze in that direction can lead to

damage such as ruptured eardrums.

rd.com 73

Cover Story Reader’s Digest