Posts from the “Myths” Category

True or False – Organic food is more nutritious than non-organic food

Posted on February 5, 2013

False.

A few hours before I wrote this section of the book I was in our family’s garden picking raspberries with my 11 year old son. We ended up picking almost two pints worth and probably ate a pint between us as we worked. Following the raspberry harvest we drifted over to the peas and simply smiled at each other as we crunched away, consuming pod and all. Growing healthy food is a topic I am very interested in and rarely if ever do we use chemicals in our garden. I guess I would consider myself an organic gardener. The organic food industry is one that is grown tremendously over the past 5 to 10 years and probably will approach the 50 billion dollar mark this year. Organic farms have traditionally been small scale operations, however, as the interest in organic increases, so does the size of the farms. Generally speaking, organically grown foods are grown without using things like pesticides and herbicides (for plant products) or hormones (for animal products) and some say that organic growing processes have less of a negative impact on the environment.

Many people believe that organically grown food is nutritionally superior to conventionally grown food, but research really doesn’t support that. Dangour and colleagues (2009) published a review article in which they identified 162 articles on organic farming. They then determined that 55 were of satisfactory quality to include in their review. These authors stated that “One broad conclusion to draw from this review is that there is no evidence to support the selection of organically produced foodstuffs over conventionally produced foodstuffs to increase the intake of specific nutrients or nutritionally relevant substances.” There may be many good reasons to grow or purchase organic food; however, to do so because of the belief that they contain more nutrients doesn’t appear to be one of them.

Reference:
Dangour A, Dodhia S, Hayter A, Allen E, Lock K, Uauy R: Nutritional quality of organic foods: a systematic review. American Journal of Clinical Nutrition (2009), Vol 90, pps. 680-685.

Categories: Myths

True or False – Chocolate is good for your health

Posted on January 29, 2013

True.

Are you one of the millions of people who love chocolate? If you are, do you sometimes feel guilty after indulging yourself? If the answer to that is yes, please keep reading! Cocoa and chocolate have been consumed for thousands of years, however, very few of us think about the health benefits associated with chocolate. In fact, it’s only been recently that scientists have started paying attention to the health benefits of chocolate. Chocolate contains compounds called flavonoids, which have been shown to have antioxidant properties, and be very beneficial to health. Research is starting to show that consuming chocolate may help reduce the risk for having a heart attack or stroke, aid in cancer prevention, lower blood pressure, improve insulin sensitivity, decrease blood clotting, and even improve skin health. In fact, there was a conference in 2007 in Milan, Italy where researchers gathered to discuss current research on how chocolate consumption impacts health. Visioli et. al, (2009) published an article in the journal Critical Reviews in Food Science and Nutrition summarizing research presented at the conference. These authors concluded “While the near entirety of experimental data indicate healthful consequences of cocoa intake, the caloric load of chocolate should not be overlooked and its consumption is to be positioned within a balanced and isocaloric diet.” Keep in mind that dark chocolate is much higher in flavonoid content than say milk chocolate which may contain few of these compounds as they can be destroyed during processing. Also be aware of the calories when eating chocolate (there’s always a downside), more isn’t always better. Even a quarter or a half an ounce of dark chocolate per day will likely improve health. Go ahead and indulge yourself, but remember, the darker the chocolate the better, and enjoy in moderation.

Reference:
Visioli F, Bernaert H, Corti R, Ferri C, Heptinstall S, Molinari E, Poli A, Serafini M, Smit H, Vinson J, Violi F, Paoletti R: Chocolate, lifestyle, and health. Critical Reviews in Food Science and Nutrition (2009), Vol 49, pps. 299-312.

Categories: Myths

True or False – If you wait to drink until you are thirsty, you are already dehydrated

Posted on January 22, 2013

False.

I usually get thirsty two or three times during a normal day. If it is a weekend and I am at home working in the yard or the garden, or playing sports with my three children, I might actually experience thirst a half dozen or more times during the day. Should I be afraid that I am chronically dehydrated and that my health is at risk? Most experts are now saying no. This notion of “If you wait to drink until you are thirsty you are already dehydrated” has been around for some time and is something that many people believe. However, there really is very little scientific evidence to support the idea. Heinz Valtin (2002) in an article published in The American Journal of Physiology – Regulatory, Integrative and Comparative Physiology states this notion or fear of being dehydrated if you experience thirst is a myth. He writes that a rise in plasma osmolality (the proportion of materials like glucose and sodium in blood) of 2% can elicit thirst and that a plasma osmolality increase of roughly 5% is when someone would be considered dehydrated.

I spoke with one of my colleagues, Dr. Carl Foster about this. Dr. Foster is a well respected exercise physiologist and a past president of the American College of Sports Medicine. Dr. Foster stated that the idea of already being dehydrated if you got thirsty was a common belief 8 to 10 years ago, and that most experts today think it is perfectly acceptable to let thirst be your guide in regards to drinking fluids. There certainly is nothing wrong with consuming fluids before you are thirsty, but it seems that our society has gotten to the point where the expected norm is to carry a water bottle everywhere you go and be sipping water every 10 or 15 minutes. I’m sure the companies that are making millions keeping us all well hydrated will continue to be in support of that idea.

Reference:
Valtin H: “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8 X 8”? The American Journal of Physiology – Regulatory, Integrative and Comparative Physiology (2002), Vol 283, pp. 993-1004.

Categories: Myths

True or False – When eating celery, you burn more calories than you consume

Posted on January 14, 2013

False.

It is a common belief that eating certain foods results in your body burning more calories than are actually contained in the food itself. These foods are referred to as negative calorie foods. The belief revolves around the fact that when we eat food we do expend some energy breaking down and absorbing that food. This is referred to as the thermal effect of a meal (TEM), the thermal effect of food (TEF), the thermal effect of eating (TEE), or diet induced thermogenesis (DIT). Celery is one of the foods that many claim to be a negative calorie food. Other foods often listed as negative calorie foods include cucumbers, mushrooms, lettuce, onions, zucchini, etc. When you think about it, most of these foods are basically water and fiber. With the number of people who struggle with being overweight now days, this concept of eating negative calorie foods for weight loss purposes has gotten to be very popular. In fact, I did an internet search using the terms “negative calorie foods” and quickly found lots of information on negative calorie diets. I got really excited when I read more information on the negative calorie diet. Apparently, when you follow this diet you can eat all the food you want! While eating all the food you want, you will lose lots of weight. Best of all, if you try this diet you will never be hungry again. I’ll have to admit, I am a bit skeptical. When I read material like that I often think back to my parents telling me the old adage “if it sounds too good to be true it probably is”. I recently came across a book written by Registered Dietician Roberta Larson Duyff for the American Dietetic Association (1999). The author does say that the notion of eating celery as a weight loss aid because you burn more calories than it contains is a myth, and if there is a weight loss benefit it is likely because you are eating the celery in place of higher calorie foods.

Reference:
American Dietetic Association: Food folklore: tales and truths about what we eat. Nutrition Now Series – Tips From the Nutrition Experts (1999), pg 80.

Categories: Myths

True or False – Eating while watching TV increases caloric consumption

Posted on January 7, 2013

True.

Watching TV has become a routine part of most of our lives. Different sources report slightly different statistics on just how much TV we watch. Generally speaking adults tend to watch 2-3 hours of TV a day, with children watching more like 3-4 hours of TV a day. Many people like to eat while watching TV and my wife and I are no different. Like most people we live busy lives, jobs, kids, hobbies, etc., and watching 30 to 60 minutes of television before bed is one way we relax and unwind at night. When we watch TV, we tend to eat. For me, it usually starts with a large bowl of popcorn (we are popcorn addicts)! Then I often make a sandwich, when that’s gone I eat an ice cream cone, I’m somewhat health conscious so I usually have a piece of fruit, and top it off with a large bowl of cereal. Research supports the idea that we tend to eat more calories when we watch TV. Blass and colleagues (2006) did a study and reported that college students ate more pizza (36% more calories) and more macaroni and cheese (71% more calories) during a 30-minute meal while watching TV.

Also, consider the types of food people generally eat while watching TV. We often chose foods like pizza, chips, cookies, ice cream, etc., foods that are calorie dense, but not necessarily nutritionally dense. Very rarely will you find someone sitting down and gorging themselves on broccoli, asparagus, tofu, carrots, spinach, egg whites, and tomatoes while watching TV. What can you do to try and limit the number of calories you eat in front of the TV? If you eat some or all of your meals in front of the TV, turn it off! Try to make healthier choices, eat some cherries instead of the ice cream. Finally, if you must eat things like chips, put a serving or two on a plate and put the bag back in the cupboard. That will help keep you from mindlessly eating until you hit the bottom of the bag.

Reference:
Blass E, Anderson D, Kirkorian H, Pempek T, Price I, Koleini F: On the road to obesity: Television viewing increases intake of high-density foods. Physiology and Behavior (2006), Vol 88, pps. 597-604.

Categories: Myths

True or False – Caffeine improves exercise performance

Posted on January 3, 2013

True.

The majority of people consume beverages that contain caffeine at some point during their day. For many, it’s the two or three cups of coffee they drink early in the morning, for others, it comes in the form of tea or soda. Individuals who purposely consume beverages that contain caffeine often say it gives them a bit of a jolt, helps they wake up or feel more awake, and helps give them energy. Might this translate into improved performance when exercise or physical activity is involved? The overwhelming answer from the research that has been conducted up to this point is yes, caffeine consumption does improve exercise performance. Caffeine is considered an ergogenic aid, something that enhances performance. There have been a tremendous number of studies conducted on caffeine and performance with many of the studies showing that performance is improved by about 10% with the aid of caffeine.

Graham (2001) published an extensive review article on the topic in the journal Sports Medicine, and stated that there is no doubt that caffeine enhances physical performance; he referenced many articles to support the claim. He also stated that he was not aware of any published study that has shown a negative effect of caffeine on performance. Keep in mind, though, that not everyone responds the same to caffeine. Don’t assume you can drink a cup or two of coffee and immediately knock off 3 or 4 minutes from your 5k race time or go out and bike an additional 20 miles. For some, consuming caffeine can result in getting jittery or fidgety and can contribute to increased nervousness or anxiety in others. The International Olympic Committee has set a limit on how much caffeine can be ingested by Olympic athletes. Consuming 1 or 2 cups of coffee likely wouldn’t cause an athlete to be over the limit, but consuming 5 or 6 cups certainly could.

Reference:
Graham T: Caffeine and Exercise: Metabolism, Endurance and Performance. Sports Medicine (2001), Vol 31, pps. 785-807.

Categories: Myths

True or False – Eating more slowly results in consuming fewer calories

Posted on December 18, 2012

True.

The trend in our society is to do everything in a hurry and many Americans report that they feel rushed on a daily basis. Regretfully, this often carries over to our nutritional practices as well. I read recently that Americans now eat 1 out of 5 meals (that’s 20%!) in their cars. I remember, as will many of you, being scolded by my mother for eating too fast. I was the youngest of four boys. Breakfast, lunch, and dinner were by no means times to sit down, talk, and socialize as a family, they were times to eat. I imagine we looked like pigs bellying up to a trough during those meals. At times, I still find myself eating too fast and have also wondered if the speed at which we eat impacts the number of calories we consume. It looks like research is starting to address that very question.

An interesting study conducted by Andrade and colleagues (2008) and published in the Journal of the American Dietetic Association examined number of calories consumed and satiety (the feeling of being full and satisfied after a meal), in participants who either ate a meal quickly (in 8 minutes) or slowly (in 29 minutes). The authors results showed that research participants who ate fast consumed on average 645 calories, whereas those who ate more slowly consumed 579 calories. Interestingly, those participants who ate slower also consumed more water during the meal, 409 grams of water verses 289 grams for those who ate quickly. The slower eaters also rated the meal as more satisfying and pleasant. So, there appears to be a number of benefits to eating slower, though I imagine the scolding I received from my mother for eating too fast came from a fear of choking. One of the reasons we might eat less when we eat slowly is that it takes about 20 minutes for our body to signal itself when it is full. My advice is to slow down, enjoy your food, and you will likely take in fewer calories.

Reference:
Andrade A, Greene G, Melanson K: Eating slowly let to decreases in energy intake within meals in healthy women. Journal of the American Dietetic Association (2008), July 2008, pps. 1186-1191.

Categories: Myths

True or False – Drinking coffee can help prevent Type II Diabetes, Parkinson’s, and Alzheimer’s Disease

Posted on December 10, 2012

True.

I’m very much like 100 million or so other Americans in that I drink coffee on a regular basis. I think we all know someone (like me) who doesn’t function all that well in the morning until about cup number two or three. Much to my dismay, I remember years ago hearing reports of how drinking coffee could increase the risk for cancer and heart disease. There has been a tremendous amount of research conducted on coffee. I recently performed an electronic search through the library for scientific references using the word “coffee” and came up with nearly 23,000 hits. In a nutshell, the thousands of studies conducted on coffee suggest there are far more health benefits related to drinking coffee than there are risks. Taylor and Demmig-Adams (2007) published a review article on the health risks and benefits of coffee drinking. The authors concluded that “The most currently available evidence suggests that coffee drinking can help reduce the risk of several diseases, most notably type 2 diabetes, Alzheimer’s disease, and Parkinson’s disease, although the underlying mechanisms for this effect are still being investigated”. Other review articles have come up with very similar conclusions. Other studies also suggest that drinking coffee can help reduce the risk of certain cancers and even heart disease. One of the reasons coffee may be beneficial for health is that it is loaded with antioxidants. Antioxidants are molecules that help prevent healthy cells in our body from being damaged. Even with all the benefits of coffee, there can be a downside to drinking it. For some, coffee can cause the jitters or the shakes, can increase heart rate, and can result in higher levels of anxiety or nervousness. Also, those who are pregnant, have hypertension, are at risk for osteoporosis, or have epilepsy should talk to their doctor about drinking coffee.

Reference:
Taylor S & Demmig-Adams B: To sip or not to sip: the potential health risks and benefits of coffee drinking. Nutrition & Food Science (2007), Vol 37, pps. 406-418.

Categories: Myths

True or False – Eating carrots improves your vision

Posted on November 30, 2012

False.

Proposed links between certain foods and improved eyesight have been discussed for hundreds and maybe even thousands of years. When the focus is improving eyesight, carrots usually dominate the conversation. Many mothers and fathers have told their children to eat their carrots because it would improve their eyesight, especially in the dark. Truth be told, there is little to no evidence supporting the idea that eating carrots leads to better vision. Supposedly this myth originated during WWII when Britain’s Air Ministry pilots started shooting down more Nazi bombers at night. The pilots were relying on a new technology in their war efforts, Airborne Interception Radar, but the Air Ministry didn’t want the Nazi’s to know that. To keep their secret safe, they purposely spread a rumor that their pilots’ improved vision was due to eating tremendous amounts of carrots. Carrots are high in vitamin A, which is important for good eye health; however, vitamin A deficiency is relatively rare in industrialized nations. Authors of one study (Smith et al., 1999) asked people about carrot consumption and seeing in the dark. Surprisingly, they found that women in their study who said they ate more carrots reported higher rates of poor night vision. It’s not likely that eating carrots negatively impacted vision in these women, but as the authors state “it is probable that people attributing poor driving ability to their vision may be eating more carrots in the hope of reversing this decline”. My wife and I have both had Lasik eye surgery so we wouldn’t need to wear contacts or glasses. If we thought we could have improved our vision by eating carrots that would have been the first thing we would have tried!

Reference:
Smith W, Mitchell P, Lazarus R: Carrots, carotene and seeing in the dark. Australian and New Zealand Journal of Opthalmology (1999), Vol 27, pps. 200-203.

Categories: Myths

True or False – Eating turkey makes you drowsy

Posted on November 19, 2012

False.

You slowly push yourself away from the table after having just completed your third heaping plate of Thanksgiving dinner. The meal included mashed potatoes, gravy, stuffing, cranberry sauce, three bean salad, homemade bread, pumpkin pie, ice cream, wine, and of course lots of turkey. You slosh your way over to the sofa where you settle in and get comfortable. Your intention is to watch some Thanksgiving Day football. However, even with nearly a dozen kids running crazy through the house rambunctiously reenacting scenes from Star Wars, you drift off to sleep in a matter of minutes. An hour and fifteen minutes later, after getting struck by a misguided light saber strike, you wake up and realize you missed the entire fourth quarter of the game. Of course the blame for drifting off into the dream state is immediately directed at the turkey, which we all know is laced with that evil substance tryptophan. Tryptophan is an amino acid and is a precursor (helps make) serotonin.

Serotonin can be converted or turned into melatonin which has been shown to cause sleepiness and drowsiness in humans. Research has shown that giving humans L-tryptophan (Charney et al, 1982) can increase feelings of drowsiness. However, it is widely believed that tryptophan doesn’t act on the brain unless it is consumed on an empty stomach and there is no protein present in the gut (there is lots of protein in turkey). Additionally, there is not enough tryptophan in turkey to cause you to become sleepy. There is also tryptophan in eggs, beans, cheese, beef, pork, lamb, chicken, milk, barley, brown rice, fish, and peanuts, yet none of these foods are credited, or blamed for inducing sleep. Experts agree that one of the reasons we become sleepy after we eat a big meal is blood is diverted from the brain and other parts of the body to the stomach to aid with digestion.

Reference:
Charney D, Heninger G, Reinhard J, Sternberg D, Hafstead K: The effect of intravenous L-tryptophan on prolactin and growth hormone and mood in healthy subjects. Psychopharmacology (1982), Vol 77, pps. 217-222.

Categories: Myths