Up until the late 16th century, everyone "knew" that the sun and planets revolved around the Earth. Up until the late 19th century, epidemic illnesses such as cholera and the plague were "known" to be caused by a poisonous mist filled with particles from rotting things. Up until the early 20th century, the most common procedure performed by surgeons for thousands of years was bloodletting, because we "knew" that blood drained from the body balanced the whacky humors responsible for poor health. Well alrighty then.
But as misinformed as all that may sound now, our predecessors believed these "facts" with the same certainty that we believe that the Earth is round and hot fudge sundaes make us fat.
Living in a time of such dazzling science and technology, we stand firmly behind our beliefs … even if so much of what we think we know to be correct is actually wrong. Here are some of the more common misconceptions, ideas that may have started as wives' tales or that came from a faulty study that was later proven wrong. Whatever the case may be, these facts are false.
Going out in the cold with a wet head will make you sick
"Put a hat on or you’ll catch your death of a cold," screeches every micromanaging momma as her charges march off into the winter wonderland. But in numerous studies addressing the topic, people who are chilled are no more likely to get sick than those who were not. And a wet or dry head makes no difference.
Sugar makes kids go bonkers
The Journal of the American Medical Association published a review of 23 studies on the subject of kids and sugar, the conclusion: Sugar doesn’t affect behavior. And it's possible that it is the idea itself that is so ingrained as fact that it affects our perception. Case in point: In one study mothers were told that their sons had consumed a drink with a high sugar content. Although the boys had actually consumed sugar-free drinks, the mothers reported significantly higher levels of hyperactive behavior. That said, some scientists warn that sugar can make you dumb.
The Journal of the American Medical Association published a review of 23 studies on the subject of kids and sugar, the conclusion: Sugar doesn’t affect behavior. And it's possible that it is the idea itself that is so ingrained as fact that it affects our perception. Case in point: In one study mothers were told that their sons had consumed a drink with a high sugar content. Although the boys had actually consumed sugar-free drinks, the mothers reported significantly higher levels of hyperactive behavior. That said, some scientists warn that sugar can make you dumb.
You lose most of your body heat through your head
Everyone knows that you lose somewhere around 98 percent of your body heat through your head, which is why you have to wear a hat in the cold. Except that you don’t. As reported in The New York Times and elsewhere, the amount of heat released by any part of the body depends mostly on the surface area — on a cold day you would lose more heat through an exposed leg or arm than a bare head.
Everyone knows that you lose somewhere around 98 percent of your body heat through your head, which is why you have to wear a hat in the cold. Except that you don’t. As reported in The New York Times and elsewhere, the amount of heat released by any part of the body depends mostly on the surface area — on a cold day you would lose more heat through an exposed leg or arm than a bare head.
You will get arthritis from cracking your knuckles
It seems reasonable, but it's not true either. You will not get arthritis from cracking your knuckles. There is no evidence of such an association, and in limited studies performed there was no change in occurrence of arthritis between "habitual knuckle crackers" and "non crackers." There have been several reports in medical literature that have linked knuckle cracking with injury of the ligaments surrounding the joint or dislocation of the tendons, but not arthritis.
It seems reasonable, but it's not true either. You will not get arthritis from cracking your knuckles. There is no evidence of such an association, and in limited studies performed there was no change in occurrence of arthritis between "habitual knuckle crackers" and "non crackers." There have been several reports in medical literature that have linked knuckle cracking with injury of the ligaments surrounding the joint or dislocation of the tendons, but not arthritis.
You have to stretch before exercise
Stretching before exercise is the main way to improve performance and avoid injury, everyone stretches … but researchers have been finding that it actually slows you down. Experts reveal that stretching before a run can result in a 5 percent reduction of efficiency; meanwhile, Italian researchers studying cyclists confirmed that stretching is counterproductive. Furthermore, there has never been sufficient scientific evidence that pre-exercise stretching reduces injury risk.
Stretching before exercise is the main way to improve performance and avoid injury, everyone stretches … but researchers have been finding that it actually slows you down. Experts reveal that stretching before a run can result in a 5 percent reduction of efficiency; meanwhile, Italian researchers studying cyclists confirmed that stretching is counterproductive. Furthermore, there has never been sufficient scientific evidence that pre-exercise stretching reduces injury risk.
Cholesterol in eggs is bad for the heart
The perceived association between dietary cholesterol and risk for coronary heart disease stems from dietary recommendations proposed in the 1960s that had little scientific evidence, other than the known association between saturated fat and cholesterol and animal studies where cholesterol was fed in amounts far exceeding normal intakes. Since then, study after study has found that dietary cholesterol (the cholesterol found in food) does not negatively raise your body’s cholesterol. It is the consumption of saturated fat that is the demon here. So eat eggs, don’t eat steak.
The perceived association between dietary cholesterol and risk for coronary heart disease stems from dietary recommendations proposed in the 1960s that had little scientific evidence, other than the known association between saturated fat and cholesterol and animal studies where cholesterol was fed in amounts far exceeding normal intakes. Since then, study after study has found that dietary cholesterol (the cholesterol found in food) does not negatively raise your body’s cholesterol. It is the consumption of saturated fat that is the demon here. So eat eggs, don’t eat steak.