10 common health myths debunked

March 15 is "Everything You Think Is Wrong Day" — a quirky (un)official holiday that encourages us all to stay humble by reminding us we’re all capable of mistakes. It was created to help “some people to realize that they are not always right” and to “contemplate our own lack of knowledge.” And in the health world in particular, misinformation is more common than ever and spreads easily online. So let’s take this opportunity to debunk some of the common health myths we encounter.

Myth 1: Vaccines cause autism

One of the most circulated (and dangerous) health myths is the claim that vaccines are responsible for autism. Under Robert F. Kennedy Jr., a decades-long anti-vaccine activist who is now head of the U.S. Department of Health and Human Services, the Centers for Disease Control and Prevention will be expanding its research on the long-debunked link between vaccines and autism. Years of prior research have already found zero connection between vaccines and autism. There are several reasons why some people still believe this myth, including the expansion of the criteria used to diagnose autism and greater awareness, which has resulted in more documented cases, and a tendency for autism symptoms to appear around the same time that childhood vaccines are administered, creating the false impression that the two events are connected.

Myth 2: All vitamin supplements are helpful and harmless

Yes, taking a supplement is sometimes advisable, especially folic acid for pregnant women, which can prevent some birth defects, or vitamin D if you’re low in that nutrient. But taking too many dietary supplements can be bad for your kidney and liver health, and since the supplement industry is largely unregulated, products purporting to act as “immune boosters” or “gut support” aren’t always supported by research. (And, no, vitamin A cannot prevent measles.) That's why it's important to take them under the guidance of a health care provider, especially if you’re taking more than one supplement.

Myth 3: A glass of red wine is good for you

Can that glass of red wine with dinner be beneficial for your heart? It’s certainly an appealing idea that sounds (and in fact is) too good to be true. Resveratrol — a substance found in red grapes, and therefore, in red wine — does have antioxidant properties and possible cardiovascular benefits, but evidence suggesting red wine helps prevent heart disease is fairly weak. Also, you would need to drink an absurd amount of red wine to reap any of those antioxidant benefits, and the alcohol in the red wine likely negates any perks. This brings us to our next myth…

Myth 4: Moderate drinking is healthy

For years, one of the most prevalent myths in health was that moderate drinking — which the CDC defines as up to one drink a day for women and up to two drinks a day for men — was good for you and even better than abstaining from alcohol altogether. But subsequent research has found serious flaws in the studies supporting that claim, and the general consensus now is that alcohol is not a health tonic. In fact, the World Health Organization says that no amount of alcohol is healthy, and even a small reduction in drinking can decrease your risk of certain cancers and chronic diseases.

Myth 5: Only women get breast cancer

Although men are much less likely to have breast cancer than women (accounting for less than 1% of all breast cancer diagnoses), they are still susceptible. If diagnosed, breast cancer may be more deadly in men, with one 2019 study finding that male breast cancer patients had a 19% higher mortality rate than women. Men should see their health care provider immediately if they notice symptoms such as skin or nipple changes or lumps on or near the chest.

Myth 6: You only need sunscreen when it’s sunny

You might think that you only need to apply sunscreen in the depths of summer when the sun is at its strongest. But as Yahoo Life editor and lifelong sunscreen evangelist Rachel Grumman Bender always says, protecting your skin should be a year-round commitment. Experts say that the most damage from ultraviolet (UV) rays doesn’t only come from a few hardcore beach days but rather from the accumulation of lots of little sun exposure moments. And even when it’s cloudy, most UV rays will still penetrate — especially if the cloud cover is thin.

Myth 7: Having obesity means you’re unhealthy

It should go without saying that we shouldn’t make snap judgments about people’s health based on their weight. While having a higher amount of body fat — especially in your midsection — often can put you at a higher risk of developing chronic diseases and certain cancers, it doesn’t necessarily mean you currently have health issues. Even body mass index, the primary tool currently used to measure obesity, is now considered by many experts to be a poor way of gauging health on its own.

Myth 8: Your hand sanitizer will protect you from all germs

Many of us became hand sanitizer junkies during the COVID pandemic, but unfortunately, those little gels only offer so much protection. While alcohol-based hand sanitizers can kill off some pathogens, they’re not good at eliminating “non-enveloped viruses” such as norovirus, which have a hard, protein-based shell that renders hand sanitizers ineffective. No matter what virus you’re hoping to avoid, washing your hands with soap for at least 20 seconds is always the better defense.

Myth 9: Cracking your knuckles causes arthritis

Crack, crack. The sound of popping knuckles — known medically as crepitus — can feel satisfying for some and irritating for others. It’s also a common habit, with up to 54% of people saying they crack their knuckles. But experts previously told Yahoo Life that “there is no evidence suggesting that knuckle popping or cracking your joints leads to arthritis.” However, if you experience pain or discomfort along with those sounds, that’s a sign that you should visit a doctor to check for an injury or joint damage.

Myth 10: You need to walk 10,000 steps a day to be healthy

For decades, the conventional wisdom was that you needed to get in 10,000 steps (the equivalent of 5 miles) each day for optimal health. If that sounds like an impossible task, here’s some good news: You can reap major benefits by walking far less, with a recent review finding that walking just 3,143 steps can protect against premature death — and even anything above 2,200 steps (or about 1 mile) is associated with lower mortality and cardiovascular disease. As a bonus, try taking the scenic route; walking in nature can inspire awe and encourage mindfulness.