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Myths about the human body and health still prevalent

Nov. 17, 2011
Medical myths serve as a reminder that we can be wrong and need to question the “legends” often passed on in the practice of medicine, dental, hygiene and other forms of health care. Maria Perno Goldie, RDH, MS, expounds on some of these myths talked about in a recent presentation.
By Maria Perno Goldie, RDH, MS
Dr. Aaron E. Carroll and Dr. Rachel C. Vreeman are the authors of the book, Don't Swallow Your Gum! Myths, Half-Truths, and Outright Lies About Your Body and Health, and speakers at the North American Dental Hygiene Research Conference. Their light-hearted and informative presentation was well received and a welcomed addition to the program. They also authored Don't Cross Your Eyes...They'll Get Stuck That Way: And 75 Other Health Myths Debunked.(1) Dr. Carroll earned a BA in chemistry from Amherst College, an MD from the University of Pennsylvania School of Medicine, and an MS in health services from the University of Washington, where he was also a Robert Wood Johnson Clinical Scholar. Dr. Rachel C. Vreeman is an assistant professor of pediatrics in Children’s Health Services Research at the Indiana School of Medicine and co-director of Pediatric AIV/AIDS Research for the Academic Model for the Prevention and Treatment of HIV/AIDS (AMPATH). Their work has been featured in The New York Times, USA Today, The Los Angeles Times, Newsweek, and many other national publications, and they have appeared on programs such as Good Morning America, the CBS Evening News, ABC News Now, and The Colbert Report. These medical myths are a reminder that we can be wrong and need to question the “legends” we innocently promulgate as we practice medicine, dental, hygiene, and other forms of health care. Drs. Carroll and Vreeman have produced a collection of common medical or medicine related beliefs advocated by physicians and the general public, based on statements we had heard endorsed on multiple occasions and thought were true or might be true. Let’s review a few here.“People should drink at least eight glasses of water a day.” The advice to drink at least eight glasses of water a day can be found throughout the popular press. One origin may be a 1945 recommendation that stated: A suitable allowance of water for adults is 2.5 liters daily in most instances. An ordinary standard for diverse persons is 1 milliliter for each calorie of food. Most of this quantity is contained in prepared foods. If the last, crucial sentence is ignored, the statement could be interpreted as instruction to drink eight glasses of water a day. Studies have produced varying recommendations over the years, but water needs depend on many factors, including a person’s health, their activity level, and where they live. Water is the body's main chemical component and makes up about 60 percent of our body weight.
Every system in our body needs water. Water flushes toxins out of vital organs, carries nutrients to cells, and provides moisture for ear, nose and throat tissues. So how much fluid does the average, healthy adult living in a temperate climate need? The Institute of Medicine determined that an adequate intake (AI) for men is roughly 3 liters (about 13 cups) of total beverages a day. The AI for women is 2.2 liters (about 9 cups) of total beverages a day.(2) Although no single formula fits everyone, knowing more about your body's need for fluids will help you estimate how much water to drink each day.Thirst is not a signal that you’re already dehydrated. Dog mouths are not cleaner than human mouths. And spinach doesn’t get extra credit as a strength-enhancer. These “myths” are discussed by Drs. Aaron E. Carroll and Rachel C. Vreeman in the book. They looked through medical research to assess the evidence supporting various notions and misconceptions. Some of their conclusions won’t be a surprise: Flying while pregnant is safe. The best way to cure a hangover is not to drink too much. Another misconception is the belief that an average person swallows eight spiders a year. Another is that a person’s eyeballs will pop out if the eyes aren’t closed during a sneeze. Other interesting items in the book, citing actual studies, are: co-sleeping with infants, fluoridated water, vaccines and autism, etc.
Other things you may have wondered about: double-dipping with chips really can transfer bacteria into the dip, especially if the dip is runny; mayonnaise-containing food such as potato salad is far less likely than unwashed fruits and vegetables, or undercooked meat, to make you sick at a summer picnic; the five-second rule won’t protect dropped food from germs; as for swallowed chewing gum, it will simply be eliminated along with more traditional waste.Despite their popularity, many medical beliefs range from unproved to untrue. Although the authors did not perform systematic review of either the breadth of medical myths or of all available evidence related to each myth, the search methods produced a large number of references. While some of these myths simply do not have evidence to confirm them, others have been studied and proved wrong.As Thanksgiving approaches, do you think you will fall asleep from eating too much turkey? The presence of tryptophan in turkey may be the most commonly known fact pertaining to amino acids and food. Scientific evidence shows that tryptophan is involved in sleep and mood control and can cause drowsiness.(3) L-tryptophan has been marketed as a sleep aid. Read the book to find the answer!We all need to read and understand the evidence supporting our decision making. We should recognize that what we do can be based, in part, on tradition, anecdote, or art. Who actually said that patients should see their dentist every six months? While belief in the described myths is unlikely to cause harm, recommending dental or medical treatment for which there is little evidence may not be in the best interest of the patient.
1. Carroll A and Vreeman R. Don't Swallow Your Gum! Myths, Half-Truths, and Outright Lies About Your Body and Health. St. Martin’s Press: New York.2. Panel on Dietary Reference Intakes for Electrolytes and Water, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate. Consensus Report. ISBN: 0-309-53049-0, 640 pages, 6 x 9, (2004) This PDF is available from the National Academies Press at: Carroll A and Vreeman R. Medical Myths. BMJ 2007; 335:1288.

Maria Perno Goldie, RDH, MS

To read previous articles in RDH eVillage FOCUS from 2011 written by Maria Perno Goldie, go to articles.