The Medical Minute: Medical myths, part 3

By John Messmer
Penn State Family and Community Medicine
Penn State Milton S. Hershey Medical Center
Penn State College of Medicine

Myths and tall tales are part of every civilization so it stands to reason there would be many related to medicine. Here are more medical myths:

"Vitamin C prevents colds."
Linus Pauling, a Nobel Prize winning chemist, was a major proponent of the idea that vitamin C prevents colds. Even top scientists can be wrong. In fact, vitamin C in megadoses proposed by its advocates can be harmful in some cases. Vitamin C is essential for tissue integrity and proper functioning of many organ systems and is an antioxidant, but multiple studies have shown no benefit for preventing colds. Possible explanations for those who believe it really helps them are that people who take extra vitamin C every day also may be paying closer attention to taking care of themselves and naturally have fewer colds. Another possibility is the placebo effect -- if we really believe it will work, it does. In medical studies, typically about one in five people getting an inactive drug show improvement due to the placebo effect.

"Aluminum cookware causes Alzheimer's disease."
Aluminum is the third most plentiful element on earth. If it were a cause of Alzheimer's we should see more than we do. Studies in the 1970s showed brains of Alzheimer's patients had more aluminum present, but nothing has ever demonstrated a causative effect. It might get there during development of Alzheimer's rather than as the cause. Even if it were a problem, modern aluminum cookware is anodized to prevent aluminum from leaching off and most ingested aluminum is not absorbed anyway. Besides, there is more aluminum in an antacid tablet than in a meal cooked in an aluminum pot.

"Spinach is a good source of iron."
Whether we liked it or not, our mothers may have coerced us to eat our spinach because of this myth. The cartoon character, Popeye, who saved the day after eating spinach, reinforced the misconception. The idea of spinach as high in iron stems from a typographical error in a publication in 1870 in which a misplace decimal point attributed an iron content in spinach 10 times higher than in reality.

Although there is a fair amount of iron in spinach, it is in a nonorganic form not easily absorbed. Spinach also has high levels of oxalate which binds iron and prevents absorption. Large amounts of oxalate can contribute to kidney stones in people with that susceptibility. Spinach is a rich source of antioxidants, vitamins A, C and E and folic acid plus fiber, but is not as good a source of iron as the folklore suggests.

"Everyone should take vitamins."
Think about this. Humans evolved during a time when there were no health food stores or pharmacies to sell vitamins. Although many societies languished due to poor nutrition, it was improper diets that led to vitamin deficiencies, not some intrinsic physiologic need. Sailors lacking fruit developed scurvy for want of vitamin C and using polished rice contributed to beriberi, but people who ate a variety of foods in their natural state did well. For the average person who eats a well-balanced diet with multiple types of fruits, vegetables and grains, no vitamin supplements are needed.

There are a few exceptions. Women of childbearing years may not consume enough sources of folic acid and should supplement this vitamin. Older people do not require as many calories as younger people and could potentially be deficient in vitamin D, C or B vitamins so a supplement could be useful and it is thought that macular degeneration, a condition that can lead to blindness in the elderly, might be less likely with extra vitamin C, E, beta carotene and the mineral zinc. Women should consider a calcium supplement if they do not consume enough dairy and children should have a fluoride supplement if their community does not fluoridate its water.

"Over-the-counter medications are safe."
Safety is relative. All medications are potentially harmful, but there are many products that used carefully and as directed on their labels are generally safe for most people. When the Food and Drug Administration approves a medication for over-the-counter sale, their benefits should outweigh their risks, the chance of misuse should be low, the conditions they treat are usually easy to self-diagnose and the label can include enough information to use them safely. However, anti-inflammatory drugs like aspirin, ibuprofen and naproxen can cause ulcers, kidney problems, worsen high blood pressure and can interfere with many prescription medications. Acetaminophen can affect the liver if the user is a heavy drinker or has certain medical problems that affect liver function. Decongestants can raise blood pressure, stress the heart and make urination difficult. Used with an incorrect diagnosis, many medications can mask a problem and delay diagnosis. Non-medical people should understand that most over-the-counter medications are fairly safe for most people but no medication is perfectly safe for everyone.

"There are things that doctors and the pharmaceutical industry don't want you to know."
If there really were some miraculous product that could easily cure a problem, doctors would prescribe it. The supposition of this myth is that doctors don't want you to know about something so they can continue to practice and charge for treatment with costly prescription medications. Physicians earn their living by treatment and prevention of disease. If something really works, they can earn a living using it even if it is not promoted by a pharmaceutical company. Consider the least expensive and most effective way to lose weight and have more energy while simultaneously clearing clogged arteries, reducing the risk of heart disease and preventing erectile dysfunction that just about every doctor already prescribes: no smoking, regular exercise and proper diet. It costs nothing and is practically miraculous.

There are no creams, pills, nutritional supplements, or any other product that works well that is not already part of standard medical treatment. It's just hope that keeps this myth alive.

The wise person will ask for the evidence when considering something they have always thought to be true. The Internet works to propagate myths but has also made it easier to search for the truth. It pays to maintain a healthy sense of skepticism when it comes to things that "they say that ..."