Medical Myths Exposed

From cracking your knuckles to whether blondes really do have more fun, it’s time for Ask Our Doctors: Medical Myths Exposed!

Question: Does cracking your knuckles cause arthritis?
Joints, such as knuckles, are covered by a capsule which contains fluid and gas bubbles. When you crack your knuckles, the bubbles are released, causing the cracking sound. It takes time for the gases to dissolve back into the fluid, which is why knuckles cannot be re-cracked immediately. “It’s a total pet peeve of mine,” Dr. Lisa says, “but it does not cause arthritis.”

Fertility Question

Dr. Lisa explains how to determine when you are most fertile by using a fertility calendar for a typical 28-day cycle:

• Mark the day you begin your period as ‘Day 1’
• Count forward to day 14 and mark this as the beginning of your ovulation
• You are most fertile two days before you ovulate, around day 13
• After ovulation, your fertility begins to decrease

Question: If you stick your legs in the air, are you more likely to conceive?
While certain sexual positions may, in fact, impact your chances of conceiving, sticking your legs in the air during or after sex does not affect them. The missionary position ensures the deepest penetration, so the sperm are nearest to the cervix during ejaculation. Dr. Lisa does suggest that lying in bed for 10 or 15 minutes after sex may help conception. “So women need to stop figuring out all these positions,” Dr. Lisa says. “There are other ways to determine fertility and the best times to conceive.”

Question: Should you eat for two while pregnant?

While pregnant women do eat for two, they should not double their caloric intake. An expectant mother should take in an extra 300-400 calories per day. “If you eat for two, you will become two people!” Dr. Lisa exclaims. “You will have to lose that person after, and it’s really, really hard. What you want to do is you want to eat healthily.”

Question: Can drinking castor oil induce labor?

Lynn, an audience member, asks if consuming castor oil can induce labor. Dr. Lisa explains that castor oil is a laxative, and it can cause irritation of the bowels. “The only thing you’re going to get out is a lot of other stuff,” Dr. Lisa says. “It is not an inducer of labor. There are other sort of natural inducers, and what I would recommend mostly is to have sex. It helps to bring on labor. It’s not the actual action; it’s the prostate glands and the semen that actually help.”

Question: Is a dog’s mouth cleaner than a human’s?
An urban legend holds that a dog’s mouth is not only cleaner than a human’s, but that letting a dog lick a cut or scrape will make it heal faster. Is this actually true? “A lot of people think that because canine saliva actually has antibacterial properties,” Dr. Travis says. “But, canines also like to lick other canines’ behinds.”

“A dog’s mouth and its tongue are not only its washcloth,” Dr. Jim adds. “But it’s also the dog’s toilet paper. So there’s a lot of stuff going into that mouth.”

Question: Do blondes really have more fun?

A British survey of 3,000 men has found that many think blondes make better girlfriends, but more than half said that brunettes are the best wives because they are more sensible and dependable. Almost one in five men surveyed say blondes are sexier than other women, and just less than half say they have more outgoing personalities. Whatever the hair color, Dr. Travis says, “It’s all about personality.

“The truth is, it’s personal preference, but it is interesting that they found that to be true in a study,” he adds.

Pregnancy Eating Tips

Which foods to eat while pregnant and which to avoid can be confusing. Dr. Lisa offers her eating tips for a healthy pregnancy. MORE...

Question: Are cold and flu symptoms more contagious before they begin to show?
Most experts agree that adults with a cold or the flu start to be contagious about a day before they start to experience symptoms. For the flu, the contagious period then lasts five to seven days into the illness for adults. For children, the contagious period for the flu can last up to two weeks after they start to feel sick, even if they begin to feel better before that.

When symptoms such as coughs and sneezes do appear, the cold or flu spreads much easier. Dr. Travis demonstrates this with Puff Daddy, a simulated-patient robot from the University of Louisville. Puff Daddy coughs, and under a black light Dr. Travis shows just how many simulated germs spread. “The worst part about all this is that you can be contagious before you even know you’re sick,” Dr. Travis says. “You’ve got to be careful if anyone is having any symptoms. Wash your hands!”

Question: Does coffee sober you up?
Have you ever reached for a cup of Joe after a night of drinking to help get the alcohol out of your system? While coffee may help wake you up after a late night, it will not sober you up; only time can do that. The liver has to metabolize the alcohol in your system.

Question: Can eating peanut butter while breastfeeding give your baby a peanut allergy?
During pregnancy, eating peanut products does not affect the fetus because the allergens and antibodies don’t cross the placenta. While breastfeeding, however, peanut allergens can appear in the breast milk and can affect the baby.

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OAD - 1/16/2009