11 Health “Myths” That Are Actually True
Myths, half-truths, and wives’ tales are common in health. Here are 11 health 'myths' that are actually true, according to science.
Myths, half-truths, and “old wives’ tales” related to health are common and may be passed on from generation to generation. The truth is some of the things you heard about your health when you were growing up are actually true. Others, not so much. It can be difficult to separate fact from fiction when it comes to health information because sometimes new studies come out that contradict—or at least shed new light on—previous research, particularly when it comes to food and nutrition. In other cases, there simply isn’t good scientific evidence one way or another to support or discount an old wives’ tale.
Therefore, to help you separate fact from fiction, we identified 11 health myths that evidence suggests have at least a grain of truth. (Here are some medical myths you probably shouldn’t believe.)
True: An apple a day keeps the doctor away
Although eating an apple a day may not keep you from catching a cold, research suggests it is associated with greater health benefits when compared with people who don’t eat them daily. A 2015 study published in JAMA Internal Medicine found not only were daily apple eaters more likely to “keep the doctor away” with fewer physician visits, but they also used fewer prescription medications compared with non-apple eaters. This type of study, of course, may say something more about the type of people who eat apples daily, rather than the apples themselves. (Although apples do have health benefits.) Matthew A. Davis, PhD, study co-author, notes apple-eating may be reflective of an overall healthier lifestyle. “There are many other factors exhibited among apple eaters—better diet and healthier behaviors, for example,” says Davis, associate professor at the University of Michigan School of Nursing & University of Michigan Medical School. “When we accounted for these factors, the apple-eating alone does not lead to a reduction in doctor visits. We looked at other medical services and—after taking into consideration healthy behaviors—found that apple eaters used fewer medications. This makes sense—a healthy diet is associated with [fewer] health conditions that require medications.”
True: You can catch up on sleep during the weekend
The negative effects of not getting enough sleep on a regular basis is well documented—from impaired performance and concentration to increased risk of heart disease, type 2 diabetes, and even early death—and for a long time, science suggested you couldn’t “make up” missed sleep. In a 2018 study in the Journal of Sleep Research, Swedish researchers found that people who slept for five hours or less each night had a 65 percent greater chance of early death as compared with those who regularly got six or seven hours. However, they also found that people who slept five hours a night on weekdays, but longer on weekends, lived just as long as those who slept longer every night.
“You don’t make up missed sleep in hours, but you do make up missed sleep in recovery value,” says Torbjörn Åkerstedt, MD, lead author of the study and a senior professor at Karolinska Institutet and Stockholm University in Stockholm, Sweden. As for how many hours of sleep a night you should get, aim for six to eight hours, but keep in mind that quantity doesn’t always add up to quality. “People have different sleep mechanisms,” says Dr. Akerstedt. “Some sleep more efficiently than others. The best criterion for sufficient sleep is the absence of fatigue or sleepiness during the daytime.” (Here are the 9 best vitamins for sleep.)
True: Eating late will make you gain weight
Late-night eaters tend to weigh more and have a higher body mass index (or BMI, a ratio of weight to height) than those who eat earlier in the day. A 2019 study in the Journal of Obesity suggests that having a late dinner or bedtime snack is associated with a higher probability of being overweight or obese. Specifically, researchers found nighttime eating behaviors, including late dinner and having a bedtime snack, with skipping breakfast, was associated with a higher risk of being overweight compared with those who did not engage in night eating. The researchers believe this is because eating at night can disrupt your circadian rhythms and your body’s ability to regulate blood sugar levels. Don’t fall for these 15 food myths that may lead to unhealthy gain weight.
True: Going outside without your jacket may give you a cold
A 2015 animal study published in the Proceedings of the National Academy of Sciences shows that immune cells in your nose and upper airway may not function as well in cooler temperatures. Plus, viruses can become more virulent in the cold. That’s because cold weather makes the outer membrane of the flu virus solidify, so the germ becomes more durable and easier to transmit, according to the researchers. Once it enters your respiratory tract, the gel coating liquefies and the virus is ready to wreak havoc on your body. Will you immediately fall ill if you go outside without a coat? Maybe not, but keeping yourself warm may help you fight off viruses more effectively. Check out these 8 habits doctors use to avoid colds and flu.
True: Sitting too close to the TV is bad for your eyes
Actually, this is a partial myth: Sitting close to the TV seems to be relatively safe, and research suggests the only potential risks are eye strain and fatigue. However, staring at your smartphone may cause some damage. A study published in 2018 in Scientific Reports that looked at laboratory-grown cells suggested that the blue light from a smartphone or computer might harm cells in the retina. Other scientists worry about the potential impact on children, in particular, because of their early exposure. In a 2015 study of 350 kids published in Pediatrics, half had their own television and three-fourths their own mobile device by the age of four. Nearly all the children in the study used mobile devices, and most started using them before age one. More study is needed to determine if there are eye-health risks of the light exposure in children. (Check out these health “facts” that are no longer true.)
True: Spicy foods may lead to weight loss
If you’re looking to lose weight, eating spicy foods that contain capsaicin may help. A 2017 animal study in Bioscience Reports suggests that the capsaicin in chili peppers may help with weight loss by encouraging thermogenesis—the process of creating heat from burning fat. After the researchers added capsaicin to the high-fat diet of mice, they found capsaicin prevented weight gain by turning on thermogenesis in the body. Furthermore, mice from the study did not gain weight even when fed an unhealthy diet high in fat. However, it’s important to note that this study was conducted in mice and not humans. Therefore, the findings may not be directly applicable.
True: Your allergies will disappear at the first frost
This “myth” is true, but only if you’re allergic to fall allergens—namely, ragweed. (Depending on your location, ragweed season may last six to 10 weeks, peaking in mid-September.) The good news is that cold temperatures will kill ragweed. The bad news is that allergies can still persist if you’re allergic to something that you can be exposed to during the winter, such as mountain cedar (which pollinates in South and Central Texas from December to March), Christmas trees, mold, or dust mites. Even the cold itself can cause hives and swelling if you have a rare syndrome called cold urticaria. (Don’t miss these 15 health myths that make doctors cringe.)
True: Pickle juice alleviates muscle cramps
A 2010 study in the journal Medicine & Science in Sports & Exercise suggested that pickle juice may be better for resolving muscle cramps than water. In the study, the researchers induced cramps in 10 people who were already dehydrated. Those who drank about 74 milliliters of pickle juice (about 2.5 ounces) had a shorter cramp duration than those who dank water (49 seconds vs 85 seconds).
The researchers aren’t clear on why this occurs, but they theorize that the pickle juice causes a muscular reflex when it hits the back of your throat that turns off misfiring neurons throughout the body and therefore, the cramp. The vinegar may be responsible for this phenomenon, and other researchers believe that mustard can have the same effect. Here are 6 health reasons you need to be drinking pickle juice.
True: Exercise makes you smarter
It’s not just your body that benefits from exercise; it’s also your brain. A molecule called irisin, which the body produces during endurance exercise, is credited for the brain benefits of exercise. When levels of irisin rise, genes related to learning and memory are activated, and the expression of BDNF (brain-derived neurotrophic factor) increases, creating new neurons, a 2019 study in Nature Medicine suggests. This may also lower levels of the stress hormone cortisol, as well as improve your critical thinking—not to mention your mood and stress levels. Make sure you know the truth about these myths about the human body that could harm your health.
True: When it comes to your brain, use it or lose it
Constantly challenging your brain may help stave off cognitive impairment and dementia. A 2017 study in PLOS One suggests that playing video games may improve brain function and increase gray matter in the hippocampus—the area of the brain thought to be the center of emotion and memory in older adults, ages 55 to 75. Those who played on their game console 30 minutes every day, for five days a week, over six months experienced an increase in gray matter in their hippocampus and cerebellum, along with improvements in their short-term memory. Here are 15 things that may delay Alzheimer’s.
True: Carrots are good for your eyes
Although carrots may not improve your vision, research suggests that they can help maintain it. The reason lies with beta carotene, a carotenoid (or pigment) that the body converts to vitamin A. Your body uses vitamin A to build proteins for eye cells; if you have too little of it, you might even suffer from night blindness. Furthermore, a 2015 study published in JAMA Ophthalmology found that people who ate high levels of carotenoids had a 40 percent lower risk of developing advanced macular degeneration, the most common cause of age-related blindness. Don’t like carrots? Sweet potatoes and orange peppers, as well as dark, leafy greens like spinach and kale are also rich in carotenoids. Check out these 59 common health myths that seriously need to be debunked.
- JAMA Internal Medicine: "Association Between Apple Consumption and Physician Visits Appealing the Conventional Wisdom That an Apple a Day Keeps the Doctor Away"
- Matthew A. Davis, PhD, associate professor at the University of Michigan School of Nursing & University of Michigan Medical School
- Journal of Sleep Research: "Sleep duration and mortality – Does weekend sleep matter?"
- Torbjörn Åkerstedt, senior professor at the Karolinska Institutet and Stockholm University, Sweden
- Journal of Obesity: "The Association of Having a Late Dinner or Bedtime Snack and Skipping Breakfast with Overweight in Japanese Women"
- National Academy of Sciences: "Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells"
- Scientific Reports: "Blue light excited retinal intercepts cellular signaling"
- Pediatrics: "Exposure and Use of Mobile Media Devices by Young Children"
- Bioscience Reports: "Dietary capsaicin and its anti-obesity potency: from mechanism to clinical implications"
- Allergy and Asthma Foundation of America: "Ragweed Pollen Allergy"
- Medicine & Science in Sports & Exercise: "Reflex inhibition of electrically induced muscle cramps in hypohydrated humans." Nature Medicine: "Exercise-linked FNDC5/irisin rescues synaptic plasticity and memory defects in Alzheimer’s models" PLOS One: "Playing Super Mario 64 increases hippocampal grey matter in older adults" JAMA Ophthalmology: "Intakes of Lutein, Zeaxanthin, and Other Carotenoids and Age-Related Macular Degeneration During 2 Decades of Prospective Follow-up"