From the old wives tales handed down from our parents to the advertising material we see everyday - sometimes it's hard to discern fact from fiction when it comes to health. We shed light on seven popular health myths.
Chewing gum takes seven years to digest
It turns out that wad of Wrigley's you swallowed seven years ago hasn't actually been haunting your digestive system ever since. In fact, Rodger Liddle, a gastroenterologist at the Duke University School of Medicine, USA states that 'nothing would reside that long [in your system], unless it was so large it couldn't get out of the stomach or it was trapped in the intestine'i. It is true, however, that chewing gum is primarily composed of indigestible ingredients such as natural/synthetic elastomers, plasticising softeners, resins and preservative anti-oxidizing agents, making its digestion a more difficult and slower process than with other foodsi. But don't worry: it will come out before seven days -- not years - are upii!
Cracking your knuckles will lead to arthritis
Give it another crack! Recent studies conducted by the University of Health Sciences, USA, indicate that a history of habitual knuckle cracking does not seem to contribute to osteoarthritis in the handsiii. And while it doesn't sound healthy, the "pop" sound that the joint makes is actually doing you no harm - it's simply gases dissolved in the fluid between joints forming bubbles which pop"iv.
Low-fat products are better for you
According to Professor Kerin O'Dea, from the University of South Australia, low-fat products are not necessarily healthier for you than full fat products. Products claiming to be "low-fat" may have higher sugar or salt content than their full fat counterparts. She states that 'many low-fat foods contain the same number of kilojoules - or even more - than their full-fat counterparts because of extra sugars added to make up for the loss of taste...when the fat is removed'v.
Sitting too close to the TV will ruin your eyesight
Sitting too close to the TV will not cause blindness or permanent eye damagevi but it may cause eyestrain or may be an indication of short-sightedness in the viewer,vii according to the American Academy of Ophthalmology. Be sure to take breaks when watching TV for many hours, keep the room well lit and try not to watch TV excessively as it contributes to a sedentary lifestyleviii. If you can't see the TV without sitting close, you may have a vision problem and should seek advice from an eye doctor.
Skipping meals is a great way to lose weight
Skipping meals is such an ineffective way of losing weight that it even helps you put on weight! Studies show that skipping meals contributes to an increased appetite, meaning that when you do eat, you eat more and this leads to an increased stomach capacityix. On top of this, starving yourself will put your body into 'survival mode' where your metabolism slows down and your body conserves energy (fat) rather than burning itx.
A tan is healthy
A vital vitamin for the body, Vitamin D, comes from exposure to the sunxi. In this regard, sun exposure is healthy for the body. However, a tan is not necessarily healthy: you can still get Vitamin D from the sun while wearing a sunscreen that protects you from harmful UV rays (these are the what makes your skin tan)xi. A tan is your skin's way of protecting itself from the sun's ultraviolet (UV) rays and is an indication of skin damagexii. Exposure to UV radiation either from sunlight or a solarium will increase your risk of developing skin cancerxii, and excessive exposure to the sun will age your skin prematurely, directly causing fine lines and wrinklesxii.
Not eating carbohydrates is a good way to lose weight
'Low-carb' diets have been fashionable for a long time but this doesn't mean they are the best way to lose weight. Carbohydrates are essential for a healthy body and should not be removed from the dietxiii. If you choose to lose weight, choose good carbs - such as multigrain bread, fruits and vegetables - rather than eliminating carbs from your diet completelyxiv.
i Matson, J., 2007, Fact or Fiction?: Chewing Gum Takes Seven Years to Digest, Scientific American, http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-chewing-gum-takes-seven-years-to-digest
ii Jenkins, K., 25 health myths exposed, Canadian Living, http://www.canadianliving.com/health/prevention/25_health_myths_exposed_4.php
iii De Weber, K., Olszewski, M., Ortolano, R., 2011, Knuckle Cracking and Hand Osteoarthritis, Journal of the American Board of Family Medicine, vol. 24 no. 2169-174doi, http://www.jabfm.org/content/24/2/169.long
iv Library of Congress, 2013, What causes the noise when you crack a joint?, http://www.loc.gov/rr/scitech/mysteries/joint.html
v Australian Broadcasting Corporation, 2011, Fact Buster: Are low-fat foods always a healthy choice?, http://www.abc.net.au/health/talkinghealth/factbuster/stories/2011/04/27/3198072.htm#.UYmwraJTBIF
vi EyeSmart, Your Eyes in a High-Tech World, http://www.geteyesmart.org/eyesmart/ask/questions/q090413b.cfm
vii O'Connor, A., 2005, The Claim: Sitting Too Close to the TV Is Bad for Your Eyes, New York Times, http://www.nytimes.com/2005/06/07/health/07really.html?_r=0
viii Better Health Channel, 2013, Eye disorders - some common problems, State Government of Victoria, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Eye_disorders_some_common_problems
ix Better Health Channel, 2013, Weight loss - a healthy approach, State Government of Victoria, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Weight_loss_a_healthy_approach
x Nestlé, Food & Nutrition Myths Busted, http://www.nestle.com.au/nhw/resources/food-and-nutrition-myths-busted
xi Better Health Channel, 2011, Vitamin D, State Government of Victoria, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Vitamin_D
xii Better Health Channel, 2011, Skin cancer and tanning, State Government of Victoria, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Skin_cancer_tanning?open
xiii Better Health Channel, 2011, Weight loss and carbohydrates, State Government of Victoria, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Weight_loss_and_carbohydrates
xiv Harvard School of Public Health, Carbohydrates: Good Carbs Guide the Way, http://www.hsph.harvard.edu/nutritionsource/carbohydrates-full-story/#what-are-carbohydrates