Shot of a woman drinking a glass of water at home

April Fools’ Day brings its share of gags, but some health hoaxes best us year-round.
In honor of a day filled with practical jokes, scientists at the Oklahoma Medical Research Foundation are taking the air out of five myths as common as the Whoopee Cushion.
1. We should be taking 10,000 steps a day
In 1956, a Japanese company launched a pedometer with a name that translates to “10,000 step meter.” A half-century later, the figure remains ingrained.
“Walking is wonderful for your health, but there’s nothing magic about 10,000 steps,” said OMRF President Stephen Prescott, M.D. Indeed, a 2019 study found that in older women, an increase from 2,700 to 4,500 steps a day correlated with a significantly reduced rate of premature death.
“The important lesson is that taking more steps is always better than fewer,” said Prescott.
2. Being in the cold can give you a cold
For those whose parents insisted they bundle up or else get sick, OMRF immunologist Eliza Chakravarty, M.D., has news. “You will not catch a cold simply from being underdressed for chilly weather,” she said. “You have to be exposed to a virus.”
Although cold and flu cases peak in prevalence during the winter months, you’re more likely to get sick indoors, where germs can easily pass from person to person.
3. Drink eight glasses of water a day
More than 75 years ago, the Food and Nutrition Board recommended people should shoot for consuming 2.5 liters, or about 85 oz., of water per day. But that blanket recommendation ignored one central piece of common sense: Different-sized people have different hydration needs.
Plus, said Prescott, “A lot of the water our bodies need is in vegetables, fruit, coffee and everything else we eat and drink.” He recommends using common sense and letting thirst be your guide. “Your body will tell you when it needs water.”
4. Hold the eggs
The idea that eggs and other high-cholesterol foods are dangerous is a long-held belief. But, said Prescott, “Unless you’re in the small group of people who are very sensitive to dietary cholesterol, there’s no evidence that eating high-cholesterol foods increases a person’s risk of heart disease.”
When it comes to controlling your blood cholesterol levels, it’s saturated fats that need to be kept in check. “A diet high in red meat, butter and cheeses is much more concerning than one that includes an egg a day,” said Prescott.
5. We only use 10% of our brains
The myth that we use just a tenth of our brains has roots as old as Oklahoma’s statehood. In the more than one hundred years since, neuroscience has undergone dramatic advances.
“We know from brain imaging that no area of the brain is unused,” said Prescott. “And logically, brain injuries tell us that damage to any part of the brain can have long-lasting and devastating results.”
The falsehood is thought to have roots in encouraging people to dig into their own potential for self-improvement. The idea isn’t without merit, said Prescott. “Staying mentally engaged as you age is critical. But there are no untapped brain cells to call on to do it.”