Today's Health Tip will explore the validity of several medical issues that are commonly bandied about.  After reading each statement, decide whether it is true or false and then read on to learn more about the topic.

1. "Reading, sewing or doing other close work in dim light can damage your eyes."
In a survey on the topic, 71% of those polled had the misconception that eye damage would occur from reading under dim light.  Additionally, 66% erroneously thought that sitting too close to a television set would cause eye damage.  Reading in dim light can cause eye fatigue, but it will not cause eye damage.  When you think about it, for hundreds of years, people have been reading and working under dim light, such as oil or kerosene lamps.  While it is certainly preferable to perform these tasks with good lighting, aside from the fatigue that it creates, it does not do permanent damage.

2.  "Eating grilled meat can cause cancer."
Eating meat grilled well done or burned has been linked to several types of cancer, including colon and pancreatic.  The longer meat cooks at high temperatures, the greater the buildup of cancer-causing compounds called heterocyclic amines (HCAs)  This increased  risk of cancer is n
ot confined to grilled foods but is associated with pan-fried meats at high temperatures also.  Grilled vegetables, even well-done, do not appear to pose the same risk as overcooked meat.  You may be able to reduce your risk by precooking meats in the oven or microwave, and then finishing them on the grill for just a few minutes.

3.  "Eating chocolate will give you acne" 
This one has been debated back and forth for years.  Previously it was believed that acne development was related to factors such as hormones, heredity, and stress. Food, including chocolate, was not thought to cause it.  More recent research has found that people eating a diet with a low glycemic load (less sugar, higher fiber, etc.) were found to have healthier skin than those whose diet contained higher amounts of sugar.  This has led organizations, such as the American Academy of Dermatology, to recommend avoiding food with a high glycemic index (white bread, pasta, white rice, etc.) if acne is a concern.

4.  "Cracking your knuckles will give you arthritis."
There is no evidence that cracking knuckles causes damage, such as arthritis, to finger joints.  There is one report in the medical literature, however, of long-standing knuckle cracking resulting in injury to ligaments that support the finger joints. Additionally, people who habitually crack their knuckles have been found to have reduced grip strength as compared to people who did not crack their knuckles.
 
5.  "Undergoing anesthesia will cause your hair to fall out" 
The great majority of people undergoing general anesthesia notice no effect on hair growth or loss. There are two situations, however, in which receiving anesthesia may cause hair loss. The first is known as "pressure alopecia"--- hair loss in a specific area due to scalp pressure from the head lying in one position during prolonged anesthesia or postoperative recovery. The second is a condition known as "telogen effluvium".  This results in a more diffuse thinning of the hair on the scalp and is primarily seen following stressful events such as undergoing surgery, receiving general anesthesia or experiencing an illness with high fever.
That's all for this edition of Medical Fact and Fiction.  I hope that you found this entertaining as well as educational.  Stay tuned for the next episode.

Article Sources:
Safeguarding your sight, Harvard Health Publications
Chemicals in Meat Cooked at High Temperatures and Cancer Risk, National Cancer Institute
Acne, American Academy of Dermatology
Will Joint Cracking Cause Osteoarthritis?, WebMD
Hidden Causes of Hair Loss, WebMD

Content last reviewed by our Medical Director on 4-27-2016