If some medical mysteries are more pressing than others, then one's proximity to death should be at the top of the list.
According to Randy Newman, short people got no reason to live. Mr. Newman may want to consider rewriting his lyrics, because some scientists posit that those very same short people will outlive the rest of us.
Japanese women live longer than anyone else, with an average lifespan of 86 years -- and they're only about 58.87 inches (149.54 centimeters) tall when they're in their late 70's. Why would tiny people live the longest?
In some cases, it might have something to do with the Methuselah gene. This genetic mutation, named for a Biblical personage who reportedly lived to be 969, decreases an organism's use of insulin-like growth factor 1, a growth hormone. Animals and humans with this mutation tend to both live longer and be smaller.
But what about people who don't have the Methuselah gene? For your average guy or gal, is height an important predictor of lifespan?
If you more closely resemble the Jolly Green Giant in stature than the Keebler elves, take heart: Factors from income level to birth weight can influence the length of a person's life.
Find out more in Do short people live longer?
9. Is the brain hardwired for religion?
Religion and science are like oil and water -- destined never to mix well. But a field called neurotheology is beginning to examine the area where these two belief systems meet: in the brain.
A scientist named Michael Persinger has taken a novel approach to experimenting with how the brain and religion interact by inventing the "God Helmet," headgear with electrodes designed to create a religious experience. The electrodes send pulses through the brain, disrupting activity in the temporal lobes to create the feeling of a presence. The big idea? If we know that the brain is involved in religious experience, we should be able to manipulate the brain to create the feeling of God being present.
Andrew Newberg of the University of Pennsylvania set his investigative sights on the brains of Tibetan monks, using brain imaging to document changes as they meditated. Among other things, he found that activity in the parietal lobe decreased. This part of the brain helps you determine where other objects are in relation to yourself. So when the parietal lobes of these monks began to quiet down, they could no longer sense the boundaries between themselves and everything else; in other words, they achieved a feeling of transcendence. Newberg had the same findings with a group of nuns, proving that at least during a religious activity such as praying, the brain is in on the action.
Learn more about the intersection of God and gray cells in Is the brain hardwired for religion?
8. Is the cure for cancer a virus?
You probably know someone who's had cancer. Most of us do. We walk 5Ks and donate money and shave our heads in support. The good news for people with cancer today is that we have ways to treat it -- huge advances have been made in the past few decades. We may be on the brink of another: fighting the wildfire proliferation of cancer cells not with a drug, but with a virus.
Researchers have approached the virus-as-weapon concept differently. A Yale team took a virus related to rabies and sicced it on mice with brain cancer. The virus destroyed the cancer while leaving the other brain cells. Cincinnati Children's Hospital scientists experimented with a similar viral therapy called rQT3, which zeroes in on cancer cells but also restricts the tumor's growth by acting on blood vessels and starving it.
Cedars-Sinai researchers took a different route with the virus, using it as a way to deliver a combination protein assassin to a specific type of brain cancer. As a bonus, this method rings the immune system's alarm bells.
Lesson learned: Viruses aren't always bad. Learn more in Is the cure for cancer a virus?
7. When we lose weight, where does the lost weight go?
Low-fat, low-cal, no-carb, sugar-free: the passwords to the world of weight loss. Some people diet for health reasons, while others just want to be able to fit into their skinny jeans again. The pound-dissolving regimen begins with a careful grocery list and a fitness plan, but where does it end?
We get energy from food. Your body breaks it down and then chooses whether to use it for energy or store it in fat tissues. To lose weight, you have to burn more energy than you take in. But where does that lost weight go?
The fat in your body doesn't disappear. Think of the process as the water cycle: The rain comes down and collects in a lake, where it evaporates and returns to the air, only to end up in clouds and fall back down to Earth. The same thing happens with fat. When you burn fat, fat cells end up releasing molecules called triglycerides that eventually break down into glycerol and fatty acids. They end up being used for energy, and the byproducts of that process are things like water and carbon dioxide, which come out of us in the form of sweat and exhalation.
Find out the whole story in When we lose weight, where does the lost weight go?
6. Can a person remember being born?
Memory's a funny thing. Sometimes it's deceptive, serving up events that never could have happened, like a dead grandparent attending a birthday party. Sometimes it's selective, choosing to remember all the state capitals but not the name of your date. And sometimes, it simply has holes in it -- like for the first three years of your life.
That refusal of your memory to dish anything from babyhood is called childhood amnesia. We used to think that people couldn't remember infancy because the part of the brain that deals with memory wasn't developed yet. Not so. It turns out that even a three-month-old can make a memory. But a memory like birth doesn't stick.
Why not? Part of it has to do with brain structure. The prefrontal cortex, which is important to memory encoding retrieval, isn't quite baked yet.
Another possible explanation is that we don't have language abilities as babies, and talking about our memories is one way to make them stick. Infants also lack a sense of time, which makes it difficult to place a memory in context. Not having a sense of self yet comes into play, too -- children may not have an idea of self until they're 2 years old.
For more on memory, try Can a person remember being born?
5. Can anger be good for you?
You'd probably rather have David Banner over for dinner than the Incredible Hulk. A raging green monster just isn't the kind of guy with whom you want to make conversation. Why not? Because most people see anger as a negative emotion, and angry people as unpleasant. But it doesn't have to be that way. In fact, anger can be good.
How you express your anger is important. Being passive-aggressive and writing a nasty note, for example, doesn't help. But if you sit down with a friend and talk about why you're ticked off and what the other person can do to assuage your feelings, it can actually help your relationship. You identify weak spots and breakdowns in communication and work to correct them.
Trying to suppress your anger and not dealing with it can lead to depression, and uncontrolled anger can cause stress and violence. At its most basic, anger acts as a warning sign to let you know that something's wrong and you need to fix it. The Civil Rights Movement never would have happened had it not been for the righteous anger of a group of people.
And although anger does affect your thinking, it doesn't necessarily cloud your judgment. As an emotion, it's actually more useful than fear and can even enhance your ability to compare the strength of one argument against another. Learn how in Can getting angry be good for you?
4. Why do women have more migraines than men?
Migraines are pretty much the worst headache imaginable. Some people vomit from the pain, which can last for days. Many migraine sufferers can't even be near light and have to hide out in a dark room with a stock of painkillers. And, unfairly, women seem to get them more often than men do.
Hormones are the most obvious culprit. A woman's estrogen levels fluctuate throughout her menstrual cycle, and this hormone may be related to migraines. Contraceptives and other hormonal therapies help some female patients and worsen symptoms for others, so there's no single way to treat these debilitating headaches.
It also turns out that women's brains may handle pain differently from the way men's do. Migraineurs who see auras, a visual side effect of the headache, may be sensitive to something called cortical spreading depression (CSD), the product of an excitable brain. Waves move across the brain, causing inflammation. Blood flow increases and then decreases, resulting in pain. According to current research, women are more sensitive to CSD.
Find out more in Why do women have more migraines than men?
3. Why are some people born with a reversal of organs?
If you could look inside yourself with magical X-ray vision, you'd see some blood and a lot of squishy, shiny organs. If you have situs inversus, or reversal of organs, you'd see the same thing -- only your organs might be in the exact opposite place they're supposed to be.
So what happens when your insides are all switched around? Sometimes, nothing -- you might not even know about it until you get examined for something completely unrelated. But other times, the condition can lead to serious side effects. When the heart is on the right side of the body instead of the left, the great arteries can also be transposed. This means that the strongest part of the heart is pumping to the lungs instead of the body, leaving the weaker ventricle to take care of the body's needs.
People who have all of their organs flipped can suffer from congenital heart disease, male sterility and lung abnormalities. Another kind of organ reversal results in either no spleen or a spleen on both sides of the body -- neither of which is a good thing.
2. Are people without wisdom teeth more highly evolved?
Standing next to Cro-Magnon man, you'd probably feel pretty good about the course evolution has taken, looks-wise. But he didn't have to worry about his wisdom teeth getting impacted, and you do.
Wisdom teeth, or third molars, show up when you're in your late teens or early twenties, and they have a bad habit of coming in wrong and screwing up your mouth. This is why most people end up getting them surgically removed and spend a week eating Jell-O.
About 100 million years ago, your mouth had plenty of room for those teeth because they were needed for tearing apart and eating prey. As humans evolved, jaws shortened, crowding out those third molars.
So if you don't have any wisdom teeth at all, are you more highly evolved than the rest of us? The short answer seems to be no, because lacking wisdom teeth doesn't give a person any sort of evolutionary advantage over the rest of us. Some scientists think one day we might not have wisdom teeth at all, but because they form after birth, it may be harder for your genes to select against the trait.
Try Are people without wisdom teeth more highly evolved? for the whole enchilada.
1. Can prayer heal people?
When people say that they'll keep you in their prayers, it's usually because they're worried about you. Perhaps you've been laid off or you're dealing with a rebellious child. Or maybe you're sick.
We know that activities such as praying and meditation can lower a person's blood pressure and heart rate, which is a plus as far as your health is concerned. But can praying for someone else, also known as intercessory prayer, make a difference?
Unfortunately, it's difficult to test something that's faith-based in a scientific way. The studies that have been done have gotten mixed results: Some show a significant difference in the health of people being prayed for, while others actually demonstrate a decline.
But if we can't figure out how exactly to measure the effects of prayer or how to design a foolproof study, why do scientists keep trying? Simple: Because people believe that prayer works. According to one study, 85 percent of people pray when they're dealing with some sort of medical problem.
Can prayer heal people? We're not quite sure. But we're working on it.