Posts from the “Myths” Category

True or False – Sitting too close to the TV can damage your vision

Posted on April 16, 2013

False.

I would almost be willing to wager that every single person reading this post has at one point in their childhood been instructed by their mother or father to back away from the television set, or risk going blind. It has long been thought that sitting too close to the television can damage vision. Turns out mothers and fathers aren’t the only ones who believe this falsehood. I came across one study that reported even teachers and school children in Pakistan believed that watching television can damage vision. It is true that many years ago some referred to the television as the radiation box. Prior to 1968 televisions did emit low levels of x-rays, but I couldn’t find any studies linking television watching, even back then, to eye damage. The television sets of today do not emit x-rays or any radiation. So, watching SpongeBob up close on Saturday morning won’t damage your child’s vision, but most eye experts agree that it can cause eyestrain. Signs and symptoms of eyestrain can include red, itchy, burning, watery eyes, as wells as blurred vision. These signs and symptoms may be uncomfortable, but will usually subside or disappear in an hour if one stops watching television. Think about adults who stare at a computer screen up close for far too many hours a day. I’ve found no evidence that would suggest this cause’s eye damage either. The American Academy of Ophthalmology even reports that many kids can focus on close items better than adults. Watching television doesn’t damage vision, but research has shown (Toyran et. al, 2002) that too much television viewing contributes to obesity, headaches, back pain, and sleep problems. It’s probably a good idea to stay at least 5 feet back when watching television, and if you notice your child inching closer to the set take them in for an eye exam as that could be an indicator of nearsightedness.

Reference:
Toyran M, Ozmert E, Yurdakok K: Television viewing and its effect on physical health of schoolage children. The Turkish Journal of Pediatrics (2002), Vol. 44, pps 194-203.

Categories: Myths

True or False – Marijuana gives you the munchies?

Posted on April 9, 2013

True.

Marijuana (also known as Cannabis) has been grown and consumed for thousands of years. There are reports that marijuana was used as early as 300 AD in India to help stimulate the appetite in individuals who for whatever reason had lost the desire to eat. Keep in mind that using marijuana is illegal, unless prescribed by a physician (currently 13 states have legalized medical marijuana use). Marijuana has been shown to be an analgesic (pain reducer), has been used in the treatment of glaucoma (lowers intraocular pressure), and helps relieve nausea and vomiting. Early studies that were conducted in the 1930’s which examined whether marijuana stimulated appetite, were not always high quality studies. However, as the recreational use of marijuana increased in the 1960’s so did the interest in conducting high quality studies (e.g., studies that used control groups and attempted to standardize the doses of marijuana consumed). Most of the studies conducted support the idea that marijuana does in fact give you the munchies (stimulates appetite). The authors of one study (Cota et. al., 2003), which was published in the International Journal of Obesity state “Despite the public concern related to the abuse of marijuana and its derivates, scientific studies have pointed to therapeutic potentials of Cannabinoid compounds and have highlighted their ability to stimulate appetite, especially for sweet and palatable food”. This may be why marijuana use is thought to be helpful for patients with decreased appetites due to illnesses such as AIDS or late stage cancer, and it may be the reason people joke about taking late night runs to Taco John’s after consuming marijuana. It is believed that the active ingredient in marijuana (THC) is similar to chemicals in the body which are released when your stomach is empty with the purpose of telling the brain it is time to eat.

Reference:
Cota D, Marsicano G, Lutz B, Vicennati V, Stalla G, Pasquali R, & Pagotta U: Endogenous cannabinoid system as a modulator of food intake. International Journal of Obesity (2003), Vol 27, pp. 289-301.

Categories: Myths

True or False – Pesticide residue on foods cause cancer?

Posted on April 1, 2013

False.

There is no question that pesticides are dangerous. After all, the purpose of pesticides is to kill pests. Millions of people each year get sick from pesticide exposure and thousands are killed. However, most of those who get sick do so because they work with (e.g., produce, transport, apply) pesticides and not because they are exposed to pesticides on the foods they eat. Some people take the idea of pesticide residue on foods very seriously. I realized this one afternoon as I watched a woman at a park rinse and carefully wipe off grapes one by one before she ate them. Survey research tells us that many people believe that pesticide residue on food increases their risk for cancer. Pesticides are strictly regulated. The Environmental Protection Agency sets safety standards, known as tolerances, for how much pesticide residue can be on foods. The California Department of Pesticide Regulation (CDPR) reports that most crops are treated with pesticides. Those pesticides not only allow farmers to grow crops in areas that might not otherwise be suitable, they also result in higher crop yields, and extend shelf life of products. The CDPR also report that there is no pesticide residue on about 60% of the produce they test and that only about 1% of their test samples have pesticide residue levels that are too high. They also state that years of monitoring show that most fruits and vegetables have little or no detectable residue by the time they reach market, and even less by the time they are washed and served. Lois Gold and colleagues (1997) in an article titled Pesticide residues in food: investigation of disparities in cancer risk estimates state “Using standard methodology and measured dietary residues in the total diet study, the estimate of excess cancer risk from average lifetime exposure to synthetic pesticide residues in the diet appears to be less than one-in-a-million for each of the ten pesticides for which adequate data were available.”

Reference:
Gold L, Stern B, Slone T, Brown J, Manley N & Ames B: Pesticide residues in food: investigation of disparities in cancer risk estimates. Cancer Letters (1997), Vol 117, pps 195-207.

Categories: Myths

True or False – Going outside with wet hair increases your chance of catching a cold

Posted on March 25, 2013

False.

Mothers and fathers routinely scold their children for doing things like going out in the cold without their hats and mittens on, for having their jackets unzipped, and especially for going outside with wet hair. Many well-meaning parents still believe that going outside or going to sleep with wet hair will increase the likelihood of catching a cold. Research going back to the 1950’s has shown that just is not the case. Studies in which participants were exposed to cold viruses or even had viruses put in their nose, and then where placed in chilled or wet environments didn’t come down with more colds than participants who were exposed to viruses in the same manner but were kept in warm or normal environments. In an article titled “Acute cooling of the body surface and the common cold” published in the journal Rhinology, R. Eccles writes, “There is a widely held belief that acute viral respiratory infections are the result of a chill and that the onset of a respiratory infection such as the common cold is often associated with acute cooling of the body surface, especially as the result of wet clothes and hair. However, experiments involving inoculation of common cold viruses into the nose, and periods of cold exposure, have failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses.” Experts do agree that in order to get sick or to catch a cold, you must be exposed to a virus that causes the cold. There are roughly 200 such viruses, with rhinovirus being the culprit in the majority of cases. People often come in contact with the virus that causes a cold by breathing in viral particles after someone has sneezed or coughed or by picking up the virus from a door knob or hand rail and then touching their nose or mouth. Colds are also more common in the winter months as people tend to stay inside more and be in closer contact with one another.

Reference:
Eccles R: Acute cooling of the body surface and the common cold. Rhinology (2002), Vol. 40, pps. 109-114.

Categories: Myths

True or False – You should not eat after 9 P.M. because the calories are usually stored as fat

Posted on March 18, 2013

False.

In past generations many families held to a consistent dinnertime. Now, the typical evening of the American family is much more complicated. It often involves parents chauffeuring one or more of their children to extracurricular activities and events, making it difficult to eat at the traditional dinner hour. In an article entitled “Impact of the daily meal pattern on energy balance”, France Bellisle states “The development of the obesity epidemic has coincided with the loosening of traditional meal patterns, and it seems legitimate to ask whether this has any impact on the energy balance of individuals and their ability to control weight”. Specifically, there is a question of whether eating late at night contributes to weight gain because of how the body treats those calories. There is a common misconception among many that calories eaten in the evening (say at 9:00 or 10:00 pm) are more readily stored as fat. It seems completely logical that food eaten in the morning will be burned up by our daily activities, while calories consumed just before bedtime will not have the same opportunity, and therefore be turned into fat. There are times when even health professionals have perpetuated this popular myth. However, I could find no evidence in the medical or nutritional literature that would suggest that the body digests and stores calories any differently in the morning or at night. Most nutrition experts agree that what is important is the number of total calories eaten per 24 hour period, regardless of at what time of day they are eaten. The question may not be when are we eating, but how much are we eating? It really gets down to calories in vs. calories out. Simply put, if you consume more calories than you burn, you will gain weight. If you burn more calories than you consume, you will lose weight. It is a simple equation, but certainly a challenge to accomplish.

Reference:
Bellisle F: Impact of the Daily Meal Pattern on Energy Balance. Scandinavian Journal of Nutrition (2004), Vol 48, pp. 114-118.

Categories: Myths

True or False – Swallowing gum is dangerous as it can stay in your stomach for months or even years

Posted on March 12, 2013

False.

Many were told never to do it, most did it anyway, that is they swallowed a piece of chewing gum. This maybe the most perpetuated health myth of all time. The parental information that is usually shared with young children to deter them from swallowing gum is that gum is not digestible (which for the most part is true) and remains in the stomach or intestines where it can turn into a huge ball of sticky goo and plug up the digestive system (which for the most part is not true). People have chewed gum type substances, usually resin from trees, for thousands and thousands of years. It wasn’t until the 1840’s that a businessman noticed loggers chewing tree resin and tried to mass produce and market the resin as gum, but ultimately couldn’t find adequate supplies of the resin. Then in the 1860’s a Mexican general with the help of a New York inventor, identified a chewing gum base that became very popular. It is this gum base that makes gum chewy, which is not broken down in the system, but ultimately passes through the digestive system in about the same amount of time as other ingested materials. It is reported that swallowing gum can result in adverse effects such as diarrhea, gas, and stomach discomfort (Milov et. al., 1998). These authors even reported the cases of three children who had masses of gum removed from their digestive system. However, in one case a 1 ½ year old girl had swallowed a number of coins that was entangled with the gum, and the two other cases were of four year old children who habitually swallowed 5 or more pieces of gum a day. So, even though there are reported cases of masses of gum being removed from the intestinal tract of children, these cases are extremely rare and usually involve large quantities of gum swallowed.

Reference:
Milov D, Andres J, Erhart N, Bailey D: Chewing Gum Bezoars of the Gastrointestinal Tract. Pediatrics (1998), Vol 102, pp. e22.

Categories: Myths

True or False – Eating protein increases your metabolism more than carbohydrates

Posted on March 5, 2013

True.

Could losing weight be as easy as increasing the amount of protein you eat? I do a fair amount of reading when it comes to nutrition and have to say it can be very confusing to try and figure out how much protein we should be taking in. If you read bodybuilding and power lifting magazines, it is common to see recommendations that we should be taking in 1 or 2 grams of protein per pound of body weight. On the other hand, many nutritionists and registered dietitians say that we Americans take in more protein than we need. Whether we get too much or not enough protein, the question of whether protein increases our metabolism more than fats or carbohydrates is an interesting one and one that is getting more attention these days. It turns out that protein actually does increase our metabolism more than fat or carbohydrates do. In a review article published in the Journal of the American College of Nutrition, Halton & Hu (2004) examined previous studies that looked at whether protein increased the thermic effect of food, which they described as being the energy required for digestion, absorption, and disposal of ingested nutrients. It is generally accepted that the thermic effect of protein is 20-30%, compared to 5-10% for carbohydrates, and 0-3% for fat. Halton and Hu concluded that “Convincing evidence exists that protein exerts an increased thermic effect when compared to fat and carbohydrate. The increased amount of energy attributable to this thermic effect is probably too small to have a visible effect on weight loss in the short term, but over periods of months or years, this difference may become significant, both clinically and statistically.” So even though your body will burn more calories breaking down and absorbing protein vs. carbohydrates and fats, it is not a tremendous amount and will likely have little impact on weight in the short term.

Reference:
Halton T, Hu F: The effects of high protein diets on thermogenesis, satiety, and weight loss: A critical review. Journal of the American College of Nutrition (2004), Vol 23, pps. 373-385.

Categories: Myths

True or False – Carbohydrates make you fat

Posted on February 25, 2013

False.

Over the past ten to fifteen years there has been a sharp increase in the number of high protein, low carbohydrate diets being marketed. I believe one of the reasons so many people explore these types of diets is the mistaken belief that carbohydrates make you fat. Carbohydrates are a macronutrient; macronutrients are nutrients we need in larger quantities to help provide energy to cells for normal growth and development. Protein and fats are also macronutrients. Carbohydrates are a very important energy source for our bodies. In fact, many medical and exercise science researchers believe that carbohydrates are the preferred energy source for the brain, and also are important for supplying the energy needs of muscles and other organs in the body. Various organizations recommend that you consume somewhere between 45 and 65% of your daily calories from carbohydrates. So, roughly speaking, it is recommended that the average person consumer more than half of their daily calories in carbohydrates. If your daily caloric intake is about 2,000 calories that would mean you would want to consume roughly 250 grams of carbohydrates per day. One study published in the journal Obesity Research (1996) showed that subjects who ate a carbohydrate rich, low fat diet lost more weight and fat mass than controls that did not change their diets. I find it hard to believe that nutritional experts would recommend we consumer over half our calories in carbohydrates, if carbohydrates in fact made us fat. Additionally, it is often recommended that we consume more complex carbohydrates (whole grain pasta, vegetables) instead of simple carbohydrates (sugars). Now eating too many carbohydrates certainly does have the potential to add extra pounds to your body, just like eating too many fats or proteins. It really comes down to the total number of calories you consume.

Reference:
Siggaard R, Raben A, Astrup A: Weight loss during 12 week’s ad libitum carbohydrate-rich diet in overweight and normal-weight subjects at a Danish work site. Obesity Research (1996), Vol 4, pps. 347-356.

Categories: Myths

True or False – Ulcers are caused by stress

Posted on February 18, 2013

False.

Many of us have a stereotype in our minds of the classic ulcer sufferer. We can picture them- overworked in a high-pressure job, overstressed both at work and at home as well. Incessantly worried, they are bombarded at every side from kids, bosses, clients- the world. They eat antacids like candy and look permanently perplexed as their troubles seem to multiply. If they could just relax and unwind, de-clutter and de-stress their lives, maybe take a stress management course, then the pain in their abdomens would subside, right? As it turns out, that may not be right. In the not-so-distant past, this was the advice given ulcer patients by their physicians. Medical knowledge up until about the early 1980’s suggested that a decrease in blood flow to the stomach during times of anxiety weakened the stomach wall, making it vulnerable to harsh stomach acids. While stress is still thought to create an environment that is conducive to ulcers, it is no longer considered to be the primary culprit.

In the early 1980’s Dr. Robin Warren, a researcher, made a startling discovery. While conducting biopsies of ulcer patients, he found a bacterium which was later named Helicobacter pylori. Warren and his colleague, Dr. Barry Marshall believed that this bacterium, rather than stress, was responsible for the ulcers. Because their claim was such a divergence from conventional belief, it was met with much resistance and skepticism. Unable to convince his peers, Dr. Marshall set out to prove the theory in a radical way. He actually drank the H. Pylori bacteria. Days afterward, he became pale and lethargic and had, indeed, developed an ulcer. Ulcer research thereafter was focused on these bacteria. According to his article in the Journal of Gastroenterology, James Freston (2000) reports that “Helicobacter pylori infection is recognized throughout the world as the most common cause of both duodenal and gastric ulcers.”

Reference:
Freston J: Helicobacter pylori-negative peptic ulcers: frequency and implications for management. Journal of Gastroenterology (2000), Vol 35, pp. 29-32.

Categories: Myths

True or False – Drinking tea has many health benefits?

Posted on February 11, 2013

True.

Millions of people enjoy drinking tea, the second most consumed beverage on the planet. Until recently I had always been a heavy coffee drinker, but I had not given tea a try. Then one evening when I had a sore throat a friend recommended I try some throat-coat tea. I don’t remember exactly what type of tea it was, but it worked and I was hooked. I still drink 2 or 3 cups of coffee in the morning, but instead of continuing to drink coffee when I get to work, I now drink tea. I really love the variety of teas on the market. I’m more of a fruity / flavored tea drinker, the two flavors I have in my office right now are “Wild Berry Zinger” and “Pomegranate Pizzazz”. I spent some time on the internet investigating whether there is health benefits associated with drinking tea and found hundreds of proposed benefits. Supposedly, tea helps with hydration, irritability, headaches, memory, cardiovascular disease, blood pressure, digestion, metabolism, immunity, the flu, cavities, arthritis, Parkinson’s and even bad breath! I then looked for something more scientific on the topic and found an article by Gupta and colleagues (2008) on the beneficial effects of tea published in the International Journal of Pharmacology. These authors sited over 200 references in their paper and discussed how tea has beneficial effects on cancer, skin health, cardiovascular disease, weight loss and even our nerves. The authors stated that “Research conducted in recent years reveals that both black and green tea have very similar beneficial attributes in lowering the risk of many human diseases, including several types of cancer and heart disease.” There are few if any downsides to drinking tea, some tea does contain caffeine, so be careful if you react negatively to caffeine. So, if you currently don’t drink tea, starting to would likely be a simple way to improve your health.

Reference:
Gupta J, Siddique Y, Beg T, Ara G, Afzal M: A review on the beneficial effect of tea polyphenols on human health. International Journal of Pharmacology (2008), Vol 4, pps. 314-338.

Categories: Myths