Common Medical Myths That Many People Continue to Believe Despite Proof to the Contrary

These disproven beliefs have been repeated so often that we don’t realize they are false. I will explain them to you.

An old wives’ tale refers to “spurious or superstitious claims.” It is not that the “old wives” intentionally lied about something. Rather, they believed that certain things, like running outside in the cold, caused you to get a cold. The “old wives” truly believed this. However, subsequent research showed it is not true. The general and even medical population still perceive many other beliefs as true.

If you ask ten people if eating turkey makes you sleepy because of the L-tryptophan content, most would answer yes. But it is not true, according to this review.

“The myth is the idea that consuming turkey (and the tryptophan it contains) might particularly predispose someone to sleepiness. Actually, turkey does not contain an exceptional amount of tryptophan. Turkey, chicken, and minced beef contain nearly equivalent amounts of tryptophan (about 350 mg per 115 g), while other common sources of protein, such as pork or cheese, contain more tryptophan per gram than turkey.”

The real reason we are sleepy after the traditional Thanksgiving meal is that we drink alcohol and eat too many calories and carbs. Eating a meal of high carbs and high fats can cause drowsiness.

Yet, this often repeated myth about turkey and L-tryptophan circulates annually around that holiday. Scratch below the surface of other popular medical beliefs, and you will find more fiction.

Now, based on my research and decades of medical experience, I will dispel eight more myths for you briefly. This is not medical advice but to give you some ideas and create awareness so that you can do your own research and discuss them with your family physicians.

1 — People Should Drink Eight Glasses Of Water Per Day

After recent severe constipation, I was given written instructions by my gastroenterologist’s office to eat a high-fiber diet and have at least eight glasses of water or liquid per day. A Registered dietician gave me similar advice last year. You might be surprised that there are almost zero scientific studies or data to support this arbitrary but almost universal recommendation.

While fluid intake is important, and adequate hydration can be a major issue for infants, the elderly, and those physically active, particularly during hot weather, the exact number of ounces necessary cannot be defined by a “one size fits all” number.

Since I live in Florida and am an avid fisherman, I am familiar with dehydration issues. Rather than exact numbers, I follow what my body tells me. If I am not urinating frequently, and my urine is deep-colored, I increase my fluid intake until it is almost clear. During the hot summer months here, it is almost impossible to ingest too much fluid. However, doing it too quickly can be dangerous. There are significant risks with drinking too much water too fast. Although rare, one can die from water intoxication.

2 — Exercise Alone Can Make You Lose Weight

Unless you run marathons or are a tri-athlete, it is unlikely that exercise alone will make you lose weight. Exercise is good for bones, muscle, mental health, and perhaps longevity. But for weight loss, it contributes less to that loss or management than a good diet.

Most studies suggest an 80/20 rule. This means that to lose weight, 80% of weight loss is attributable to diet and only 20% to exercise. This is not to say that exercise is unimportant, particularly for maintaining ideal body weight. However, the belief that you can lose excess body weight with mild to moderate exercise is untrue.

3 — You Can Catch A Cold By Being Cold

Despite what your mother may have told you, being in cold and or wet weather won’t make it easier for you to catch a cold. A virus spreads a cold and not the temperature or humidity outside. While it is true that close contact with others indoors occurs more likely in cold weather, and therefore, colds spread more easily, the weather and the cold virus are otherwise unrelated. This is a good example of correlation without causation.

4 — Eating Eggs Is Bad For You

This belief has existed for so long that even many doctors believe it is true. There is no data to suggest egg whites are unhealthy. They are packed with protein, few carbs, and almost no fat. It is the egg yolk that causes disputes. The egg yolk is high in cholesterol; therefore, many people with heart disease should limit the amount ingested per week.

However, for everyone else, data suggests that up to seven eggs per week do not adversely affect your health. Rather, the butter, ham, sausage, or bacon that may be eaten along with the eggs should be restricted. They are high in saturated fats, nitrates, and preservatives.

5 — It Is Good To Cleanse Or Detox Your Body

This is untrue. Nature has designed our kidneys, liver, and gut to do this regularly. A juicing diet or colon cleansing does not do a better job of this and, in many cases, may be unhealthy. If you decide to juice at home, use a blender, not a “juicing” machine, as the latter removes healthy fiber. And no data suggests that colon cleansing “removes toxins.” It may, however, cause dangerous fluid and electrolyte depletion.

6 — Sugar Causes Children To Be Hyperactive

Based solely upon a single study in the 1970’s, sugar does not lead children to be hyperactive or have a “sugar high.” Since then, over a dozen studies have refuted this theory that sugar causes your kids to become “wild.” There are other good reasons, however, to restrict your children’s sugar intake, as it can contribute to childhood obesity and replace good calories with empty ones. The same is true for fruit juices with a large sugar content. It is far better to give your children an apple than apple juice.

7 — Honey, Maple Syrup, Or Agave Are Better For You Than Sugar

Despite popular postings, all forms of pure sugar are not great for your body. It matters little if the sugar is glucose, fructose, or sucrose. “The reality is that most added sugars are composed of glucose and fructose in varying ratios.

For example, sucrose (common table sugar) is 50% glucose and 50% fructose; the most common form of (high fructose corn syrup) HFCS (which is produced from corn starch through industrial processing) contains 45% glucose and 55% fructose; and some types of agave nectar contain up to 90% fructose and 10% glucose.”

Honey may have micro-nutrients but, on balance, is not that much healthier than pure sugar. And ingesting local honey does not significantly help your allergies. Although a National Allergist Foundation sponsored this reference cited, they are vested in making money by treating your allergies; therefore, the study could be biased. Multiple other less influenced sources show minimal allergy benefits.

8 — Breakfast Is the Most Important Meal of the Day

I love eating breakfast, so it pains me to state this is untrue. Some studies show you could consume fewer calories and lose weight if you skip it. The decision cannot be generalized, and if you have a disease that requires frequent small feedings, that is a good reason to eat something shortly after waking. And if you are prone to intense episodes of being “hangry,” like I am, it is probably not a good idea either. Here is an interesting perspective from Dr Yildiz, who has not eaten breakfast for a long time but does well.

Conclusions and Takeaways

Many other popular beliefs have not withstood the scrutiny of science. However, conventional wisdom is often neither universal nor wise. Many things you hear, are taught, or read online are not accurate or true.

The Internet makes it easy to research anything. I would stay with good medical sources and be skeptical of sites like TikTok, YouTube, Facebook, Instagram, Reddit, and Quora.

Even medical sources can be biased. Pharmaceutical drug ads support many respected medical journals. And be wary of drug studies and their conclusions if they were supported by the drug company that makes the study drug.

I tend to trust a study underwritten by the National Institutes of Health or the American Cancer Society more than Big Pharma. The modern standards for medical publications now require a study’s or drug trial’s financial sponsorship to be disclosed along with the publication.

Science is dynamic and open to changes. It is rarely static, and we all should be willing to accept new evidence if supported by good research or data.

I am a retired MD passionate about culture, health, sports, and food.