14 DAY TRIAL // There are strong differences between popular beliefs and scientific facts but when the line between science and coincidence thins, strange predictions seem to appear.
Today there are databases of information about everything, including people’s lifestyles and medical ailments, and the computer-powered studies don't just stick to the obvious health risks anymore.
You could be amazed to hear that a new analysis shows that finger length, grip strength and even height may be reliable signs of cancer, longevity and heart disease.
But Rebecca Goldin, a mathematician at George Mason University and volunteer for STATS.org, said that not all statistically-proved findings have the same value.
“It’s easy to get results that look impressive by trying a whole bunch of things on large databases of information,” she says.
“Things pop out, but they can be completely spurious because of chance,” and “it’s now a fairly common thing to see something published and have someone say that it’s not true.”
There are many studies that are published, so many that scientists are unable to keep up with the reviews – clinical trial journals alone publish about 75 in-depth studies every day, and only 11 reviews of these studies.
And even so, there are some that stand up to statistical and cause-and-effect examination, despite the fact that they are quite bizarre, Wired Science reports.
To better understand this, here are five of the most strange but credible indicators of medical risks ever discovered.
Birth Order
There are scientific findings that suggest that first-born boys have higher risks of developing testicular cancer later in life.
Elizabeth Rapley, a molecular geneticist and spokesperson for Institute for Cancer Research (ICR), said that “lots of series of studies suggest the first child is exposed to higher levels of estrogen, which gives greater risk of testicular cancer; but this has never been definitively proven.”
It appears that chemicals similar to estrogen are responsible for the doubling of the testicular cancer rates, in the past 40 years, and it is possible that they get into the water and food supplies though pesticides.
But Rapley says that maybe the highest risk of early birth order is childhood leukemia, since it develops more often in older siblings and looks like its tied to socioeconomic status.
The geneticist suspects immune system training may also have a part in all of this, because “there are suggestions that it may have to do with exposure to viruses and colds and bacteria.”
She adds that “kids who go to child care at an early age are less likely to develop leukemia than kids kept at home,” since siblings aren’t around to give them as much exposure.
Finger Length
There are at least two genes (HOXA and HOXD) that control the development of male reproductive glands in the womb, and these in turn create testosterone.
But these two genes are also responsible for the development of the hands, mainly of the index and ring fingers, and once this discovery was made, there were all sorts of hypotheses being launched about what the ration between the two fingers could really mean.
Most of the theories were unfounded, but one study that should be published in the British Journal of Cancer, concluded that there is a very important connection between finger ratio and prostate cancer – if the index finger is longer than the ring finger, a man is less likely to develop the cancer.
Rosalind Eeles, a cancer geneticist at the ICR in London and co-author of the study says that “it seems strange, but this isn’t guesswork.”
Eeles' team compared over 1,500 men with prostate cancer to over 3,000 random men, and concluded that putting behind family history and other factors, men over 60 years of age with a longer index finger were 33% less likely to develop prostate cancer.
As for younger men, the odds were even more encouraging, with an 87% average reduction in risk.
This connection needs to be tested on other populations as well, before it can become a certain indicator of prostate cancer, but Goldin said “its speed and non-invasiveness does have something going for it.”
Rapley added that “it’s way too early to say how much hand screening could help.
“If anything, it gives us more of a handle on how prostate cancer starts, that testosterone may have big role in the development of the disease.”
Flossing
Most parents tell their kids to brush their teeth and floss, everyday and they are right because it seems that even if the crud between your teeth seems harmless, several studies have shown chronic infections of the mouth – periodontal diseases, rise the risk of circulatory woes, coronary heart disease included.
Mouth bacteria can pass into the blood through the gums and it can clog arterial plaques, which can lead to inflammation and heart attacks.
Grip Strength
When people shake hands, those with a firm grip usually make a very good impression, but it seems that grip strength also has implications for establishing one's health.
A 25-year study of over 6,000 men aged 45 to 68 years, concluded that grip strength was the best predictor of the chances they had not to be disabled later in life – a weak grip doubled the risk for disabilities.
Another study including older men and women, related a good grip strength to a longer lifespan.
However, shaking hands is not enough for a healthy life, you still need to eat well, exercise regularly and avoid harmful habits like smoking.
Travel
Now here is another risk factor not many people would have thought of – travel.
The correlation was established by a study of people's behavior during the British economic rebound, in the 1970s, Rapley explained.
At that time, people made the most of their money and traveled abroad, and “many of them went to the beaches of Spain and spent a lot of time in the sun.
“We now see an increase in the rate of melanoma in that population,” said the geneticist.
Still, Rebecca Goldin reminded that when assessing any database-powered medical study, it is very important to pay attention to large samples sizes, proposed causes, chance and extraneous effects, and also to accept that other hypotheses could also be true.
But maybe the most important thing is to put a health risk into perspective, since “there’s a lot of medicine where it’s just not clear how helpful it is to know something,” said Goldin.
“If you’re doubling your risk of one in a million, for example, that’s still two in a million.
“Unless it’s got some significant impact to way we evaluate treatment, it’s hard to see any benefit.”