Don't Cross Your Eyes...They'll Get Stuck That Way!: And 75 Other Health Myths Debunked (5 page)

Which brings us to aspartame. Approved for use in 1981, it wasn’t until 1996 when folks started worrying about aspartame containing carcinogens. In that year, a paper was published that got a lot of attention. This paper discussed the fact that there had been a recent increase in the incidence of brain tumors and questioned whether this could be linked to aspartame. As usually happens with these kinds of things, the media had a field day and people began to panic. But here’s the clincher: further investigations of National Cancer Institute statistics showed that the increase in brain tumors began in 1973, eight years before aspartame was introduced. Also, most of the increases in tumors were seen in people over seventy, who actually had the least exposure to aspartame. There is no evidence to support that aspartame is the cause of increases in cancer.

But, as with vaccines and autism, once the myth is out there, the truth is hard to swallow. People started to blame their headaches on aspartame, even though a randomized, double-blinded, placebo-controlled study showed that aspartame did not cause headaches in “aspartame sensitive” people. Others started to claim that sodas with aspartame were high in methanol. Analyses show that there is more methanol in a glass of tomato juice, or in fruits and vegetables, than in a diet soda. Another randomized double-blinded, placebo-controlled study (a great study!) showed that aspartame had no effect on mood, memory, behavior, EEG results, or physiology. And, finally, a prospective study of 285,079 men and 188,905 women ages fifty to seventy-one in the NIH-AARP Diet and Health Study could detect no effect of aspartame consumption on the development of blood or brain cancers.

There’s just no evidence. In study after study, these artificial sweeteners have not been shown to be the health risks that many make them out to be. It’s a myth.

Bathroom

The door handle is the dirtiest fixture in the bathroom

One thing we hear all the time from friends and family is the lengths they will go not to touch things in the restroom. One of the most common strategies involves using a paper towel to open the bathroom door. People seem to be genuinely afraid of the door handle. Rachel recently heard a woman pushing a public bathroom door open with her elbow repeatedly say “touching the door handle in a bathroom will make you sick.” Once Rachel left the bathroom, she saw that same woman smoking. Hmm. That’s interesting.

Let’s take a breather and think this through. It’s important to think about why we assume certain things are “dirty” or can harbor infection. In the case of the bathroom, it’s because we know something “dirty” occurs there. Picture a bathroom in your head. We bet you didn’t picture a sparkling clean room, shiny and bright. We bet you pictured a dark, dank, filthy room. But it’s important to remember that that’s your impression. It’s not necessarily based on fact.

The truth is that the actual dirtiness of an object or place comes down to two factors: (1) how many people have touched it with dirty hands, and (2) how often it is cleaned. With respect to the door handle of the bathroom, we can’t vouch for (2), but we bet it’s more often than the door handle in your office. But here’s the thing, as for (1), the door handle in the bathroom is touched far more often by clean hands—they’ve just been washed—than dirty.

In fact, the door handle seems to be one of the cleanest things in the bathroom. Don’t take our word for it; it’s been studied. Dr. Chuck Gerba, known also as “Dr. Germ,” has conducted a number of studies in this area. Someone had to, we guess. In one study, he found that toilet seats and door handles are the cleanest surfaces in public bathrooms. Amazing, but true! The bathroom floor was the dirtiest thing in the bathroom by a long shot, and often contained more than two million bacteria per square inch. So don’t put your purse or briefcase on the floor (which we bet lots of you do)!

Faucets and sinks are also worse than the door handles or toilets. That’s because people don’t wash their hands before touching those. Again, this has been studied. It’s not our guess. Think back to those rules we mentioned before. Think about the many things that are touched by lots of dirty hands and never cleaned. Things like elevator buttons. Shopping carts. Money machine buttons. Supermarket self-serve checkout machines. Playground equipment. Hotel room remotes.

Should we continue?

We don’t say this to make you crazy. After all, many of you are touching these things all the time and will not get sick as a result.

Air dryers will keep your hands cleaner than paper towels

One of the best things about writing a book like this is that we get to discover some amazing science being done by people we would never otherwise hear of. One of those people is Dr. Keith Redway of the School of Biomedical Sciences at the University of Westminster in London. Believe us when we tell you that he is the man when it comes to drying your hands in the bathroom. Sure, other people have done some work in the area, but no one else—to our knowledge—has dedicated himself to the truly important question of how best to dry your hands in a public restroom. Don’t take our word for it. Go look him up.

Why is Dr. Redway’s work important? Well, how many times have you finished washing your hands at the sink and been presented with the impossible choice of whether to use the hot air dryer or paper towels? From what we see online and hear from many of you, the overwhelming choice would be to use the air dryer. People believe it’s more sanitary than paper towels. After all, you need to touch nothing to use it. Many air dryers even have claims about being more sanitary printed right on the machine.

But is that true? In a series of experiments, Dr. Redway and a colleague of his decided to find out. For each of these studies, they compared different paper towels, warm air dryers, and newer jet air dryers.

First, they looked at how well each of these methods achieved dryness. After all, that is the primary purpose of drying your hands. Specifically, they measured the amount of water remaining on the hands at different times up to one minute. They found that all five types of paper towels and the jet air dryer achieved 90 percent dryness by ten seconds. The warm air dryer took much longer to achieve the same effect. Make of that what you will.

The next study was where it gets interesting. How much does using each of these drying mechanisms affect germs on your hands? They took twenty people and measured the numbers and types of bacteria on their hands both before and after using two types of paper towels and the warm air and jet air dryer. Both types of paper towels reduced the number of all types of bacteria on both the palms and fingertips. Warm air dryers, on the other hand, actually increased the number of all types of bacteria and the jet air dryer increased the number of most types of bacteria on both the palms and fingertips. The paper towels were the obvious winners in terms of reducing bacteria on hands.

But they weren’t done yet. For their next study, they took ten people and artificially contaminated their hands with a yeast suspension. Again, they had them dry with two types of paper towels and the warm air and jet air dryer. The point of this was to see how these drying methods contaminated the rest of the environment. They found that the jet air dryer dispersed the contaminant over two meters from where the dryer was located. The warm air dryer was slightly worse than the paper towels in that it dispersed more contaminant, but only directly below the dryer.

There’s more. In a final experiment, they went to sixteen public restrooms in a London rail station and swabbed the jet air dryers to see what kind of bacteria was there to be potentially spread around the room and onto hands. They also measured what was contained in air emitted from them over a ten-second period. They found a large number of bacteria, some of which were potential pathogens.

So to sum it up, paper towels dried just as well as anything, removed more bacteria that were on the hands already, and did not contaminate other parts of the bathroom. Seems like an easy decision on which to use next time.

We should note that other work has been done comparing air dryers to paper towels. Some of the work agrees with Dr. Redway’s findings. Some of it finds less of a difference between the methods. We should also note that Dr. Redway has often been funded by the paper towel industry in his research. But we can find no fault with his methods, and no one seems to have the single-mindedness of his calling.

The idea that hot air or jet air dryers are superior (in cleanliness or drying ability) is simply a myth.

Bubbles

The bubbles in soda will make your bones brittle

There are plenty of arguments to be made about the negative nutritional effects of soda, especially nondiet soda, which is full of empty sugar calories. One thing about soda that is not harmful, though, is its carbonation. In spite of this, many people believe that the bubbles in soda will negatively affect your bone structure.

This belief can be blamed, in part, on misunderstanding some studies from the turn of this century. A study published in the
American Journal of Clinical Nutrition
found that excess urinary excretion of calcium occurred when people drank carbonated drinks with caffeine. That means that people drinking carbonated, caffeinated drinks were peeing out more calcium. However, this study also noted that, later in the day, the kidneys compensated by lowering the amount of calcium excreted in the urine. This meant the overall loss of calcium was negligible. They concluded that the seemingly negative bone health effects of drinking carbonated beverages were likely due to the fact that people drinking soda were less likely to drink milk. Since this research was funded in part by Dairy Management, Inc., a significant conflict of interest exists.

There is some evidence that carbonated cola drinks might have some connection with weaker bones. Another study was conducted by scientists at Tufts University. They looked at data from 2,500 women and men (ages forty-nine to sixty-nine) who took part in the Framingham Osteoporosis Study. They found that noncola carbonated drinks were not associated with low bone mineral density; cola intake, on the other hand, was associated with lower bone mineral density at the hip in women, but not in men, and in neither group’s spines. There was a dose response, in that women who drank more cola had more of an effect. Contradicting the theorizing at the end of the study, women who drank more cola did not drink less milk, although their overall intake of calcium was lower. This study offers some suggestion that there might be a tie between weaker bones and cola, but not with carbonation.

Backing this up is an additional study published in the
British Journal of Nutrition
in 2005. Researchers gathered a group of otherwise healthy women who had gone through menopause and compared those who drank noncarbonated mineral water to those who drank carbonated mineral water. Specifically, they looked at whether tests of blood and urine could detect changes in bone turnover, a sign of bone weakening. They could detect no differences after eight weeks. The carbonation alone clearly does not make a difference.

Even the studies that came out against soda in some way focus on colas. None specifically implicates carbonation. There seem to be no problems with sparkling mineral water or seltzer. The carbonation is not to blame for any bone mineral problems or for low levels of calcium. And even if you think caffeine or other things in colas might take away your body’s calcium, go ahead and make sure to get enough calcium from other sources. But don’t worry about the bubbles. They won’t do you any harm.

Caffeine

Caffeine stunts your growth

Aaron loves coffee. Loves it. In fact, he’s somewhat of a coffee nut and has been known to roast his own beans. But when he was young, his parents—like many of yours—told him that he couldn’t drink coffee because it would stunt his growth. That was the line in Rachel’s family too, but since they were all tall Dutch people who had consumed massive amounts of coffee from young ages, the threat didn’t hold much credence.

It’s not totally clear where this myth comes from. Ironically, some believe it stems from the same literature that allegedly linked carbonation to brittle bones. If you remember, those studies found that it wasn’t the bubbles in the drink, but perhaps the caffeine that led to problems in calcium in bones. Some people may have extrapolated this to mean that caffeine reduces the calcium available to your bones, which leads to bone problems, which leads to stunted growth. Case closed!

Or not. When we follow coffee or caffeine drinkers over time in good prospective studies, we see that this really isn’t the case. Growing bones does require your body to use calcium. If caffeine prevents your body from absorbing calcium, then it seems feasible that caffeine would stunt bone growth. Science does not bear this out. In studies, caffeine did slightly limit how well the gut absorbed calcium. However, the studies also showed that the body compensates easily for this change in calcium absorption, by decreasing how much calcium it gets rid of in your pee over a twenty-four-hour period. The overall difference in calcium absorption is quite small. In fact, the study finding that calcium was not absorbed as well when you drink caffeine stated that whatever negative effects the caffeine had on calcium absorption could be overcome by drinking an extra one or two tablespoons of milk.

Some posit that people who drink caffeine may be taking in less dairy or drinking less milk. That’s possible, but it’s a far cry from claiming that coffee stunts your growth.

There’s more. Another study enrolled eighty-one girls between ages twelve to eighteen to see how caffeine affected their total body bone mineral gain and hip bone density over a six-year period. One group consumed less than 25 mg of caffeine per day, one consumed 25 to 50 mg of caffeine per day, and one consumed greater than 50 mg of caffeine per day. The researchers found that there were no significant differences among the three groups with respect to the bone health. Caffeine intake at various levels did not affect bone health or growth.