The first recorded syphilis epidemic flared up in war-torn Naples in 1494, only two years after Columbus discovered the New World. From there syphilis spread throughout Europe. Ever since then, controversy has raged about the origin of syphilis.

A popular belief is that Columbus’s crew got infected in the New World and brought the spirochete back to Europe, where they transmitted the disease to others while serving as mercenaries during the first Italian War. The competing pre-Columbian hypothesis asserts that syphilis was always present in the Old World yet wasn’t recognized until 1494.

{ Spirochetes Unwound | Continue reading }

Twenty years ago the average fashion model weighed 8% less than the average woman. Today, she weighs 23% less. (…)

Most runway models meet the Body Mass Index physical criteria for Anorexia.

{ Fashionista | Continue reading }

photo { Ulrich Lebeuf }

In a new study from the Centre for Addiction and Mental Health (CAMH), people with schizophrenia showed greater brain activity during tests that induce a brief, mild form of delusional thinking. This effect wasn’t seen in a comparison group without schizophrenia.

“We studied a type of delusion called a delusion of reference, which occurs when people feel that external stimuli such as newspaper articles or strangers’ overheard conversations are about them,” says CAMH Scientist Dr. Mahesh Menon, adding that this type of delusion occurs in up to two-thirds of people with schizophrenia. “Then they come up with an explanation for this feeling to make sense of it or give it meaning.”

The study was an initial exploration of the theory that the overactive firing of dopamine neurons in specific brain regions is involved in converting neutral, external information into personally relevant information among people with schizophrenia. This may lead to symptoms of delusions. “We wanted to see if we could find a way to ’see’ these delusions during Magnetic Resonance Imaging scanning,” says Dr. Menon.

{ EurekAlert | Continue reading }

Schizophrenia is a mental disorder characterized by a breakdown of thought processes and by poor emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social or occupational dysfunction. The onset of symptoms typically occurs in young adulthood, with a global lifetime prevalence of about 0.3–0.7%.

Genetics, early environment, neurobiology, and psychological and social processes appear to be important contributory factors; some recreational and prescription drugs appear to cause or worsen symptoms. Current research is focused on the role of neurobiology, although no single isolated organic cause has been found. The many possible combinations of symptoms have triggered debate about whether the diagnosis represents a single disorder or a number of discrete syndromes.

Despite the etymology of the term from the Greek roots skhizein (”to split”) and phren- (”mind”), schizophrenia does not imply a “split mind” and it is not the same as dissociative identity disorder—also known as “multiple personality disorder” or “split personality”—a condition with which it is often confused in public perception.

The mainstay of treatment is antipsychotic medication, which primarily suppresses dopamine (and sometimes serotonin) receptor activity.

{ Wikipedia | Continue reading }

photo { Brian James }

Is losing weight as simple as doing a 15-minute writing exercise? In a new study published in Psychological Science, women who wrote about their most important values, like close relationships, music, or religion, lost more weight over the next few months than women who did not have that experience.

{ APS | Continue reading }

The brain’s ability to function can start to deteriorate as early as 45, suggests a study in the British Medical Journal.

University College London researchers found a 3.6% decline in mental reasoning in women and men aged 45-49.

Previous research had suggested that cognitive decline does not begin much before the age of 60.

{ BBC | Continue reading }

photo { Larry Sultan }

Brooke Greenberg (born January 8, 1993), is an American from Reisterstown, Maryland, who has remained physically and cognitively similar to a toddler, despite her increasing age. She is about 30 inches (76 cm) tall, weighs about 16 pounds (7.3 kg), and has an estimated mental age of nine months to one year. Brooke’s doctors have termed her condition Syndrome X.

{ Wikipedia | Continue reading }

Say “placebo effect” and most people think of the boost they may get from a sugar pill simply because they believe it will work. But more and more research suggests there is more than a fleeting boost to be gained from placebos.

A particular mind-set or belief about one’s body or health may lead to improvements in disease symptoms as well as changes in appetite, brain chemicals and even vision, several recent studies have found, highlighting how fundamentally the mind and body are connected.

It doesn’t seem to matter whether people know they are getting a placebo and not a “real” treatment. One study demonstrated a strong placebo effect in subjects who were told they were getting a sugar pill with no active ingredient.

{ WSJ | Continue reading }

The inside of the human body is a bacteria-free zone. Bacteria are certainly within you, but they exist only in areas that have a direct channel to the outside world, such as the mouth, intestines and the surface of the skin. These areas are well protected by a layer of cells (epithilial cells) which form a protective barrier to keep away the nasties of the outside world. That’s why there are healthy stomach bacteria, but no healthy liver bacteria. From a certain point of view your lungs and digestive tract still are the outside world, which is why bacteria can get in and live there, sometimes perfectly happily without causing any trouble at all.

Major problems start to happen, however, once bacteria get through that epithelial barrier and into the tissues of your body. Which is why the first bacteria of the new year is the oral bacteria Fusobacterium nucleatum, which has a trick to open up little doors in blood vessels. These aren’t massive holes, not big enough to cause bleeding but large enough to let it and other bacteria into the bloodstream.

This is a big issue, because once the bacteria get into the blood-stream they can travel around anywhere within the body. It’s not  just the blood-vessels in the mouth that the F. nucleatum can get into, it can also bypass a lot of other cellular barriers such as the blood-brain barrier that keeps bacteria out of your brain, and the placental barrier that guards the passage of substances between a pregnant mother and the foetus.

{ Scientific American | Continue reading }

photo { Heike Aumüller }

There are two different types of alcohol-induced blackout: en bloc, a complete loss of memory for the affected time period; and fragmentary, where bits and pieces of memories remain. The en bloc blackout is more likely to occur when a large quantity of alcohol is ingested within a small time period.

(…)

Alcohol primarily interferes with the ability to form new long–term memories, leaving intact previously established long–term memories and the ability to keep new information active in memory for brief periods. … Blackouts are much more common among social drinkers—including college drinkers—than was previously assumed, and have been found to encompass events ranging from conversations to intercourse. Mechanisms underlying alcohol–induced memory impairments include disruption of activity in the hippocampus, a brain region that plays a central role in the formation of new autobiographical memories.

(…)

Women are more susceptible to alcohol blackouts than men (and recover more slowly) because of their generally less muscular body composition, and gender differences in pharmacokinetics.

{ The Neurocritic | Continue reading }

According to research funded by the U.S. National Institutes of Health, nearly 25 percent of older adults had small pockets of dead brain cells that may have been caused by unnoticed “silent strokes.” (…)

Another study also published by the journal Neurology this week suggested that certain vitamins and a low-trans-fat diet may help preserve memory loss.

The researchers found that trans fat (found in fried and many processed foods) contributed to “more shrinkage of the brain” in addition to less cognitive recognition.

{ Neon Tommy | Continue reading }

The exchange of gifts at a wedding is customary in cultures all around the world. To my knowledge, however, there are no cultures in which bride and groom traditionally trade poisonous presents. (…)

If we were worried the bride might be brutally devoured on her way to the reception (by her new in-laws, perhaps), a gift of this kind might be precisely what she needs to stay alive.

An unlikely dilemma? For humans, perhaps so — but not for insects. And there are indeed certain species of insects whose mating rituals feature precisely this kind of gift, generally one given by the groom to the bride. His intentions in so doing are strictly honorable, of course, for females who receive such presents are better-equipped to deter predators.

{ Puff the Mutant Dragon | Continue reading }

Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS), afflicting 3% to 8% of women. It is a diagnosis associated primarily with the luteal phase of the menstrual cycle. Up to one-third of women diagnosed with PMDD report residual symptoms into the first 2 or 3 days of the follicular phase.

{ Wikipedia | Continue reading }

Your book starts with the idea, which was very prominent and commonly believed by a large group of people, that fat–eating fat and fat in your diet, particularly animal fat–isn’t good for you and it leads to heart disease. How did that come to be accepted wisdom in the medical profession?

First, let me say I think it’s still commonly believed by most people, and the latest dietary guidelines are trying to get us to limit our fat intake, and limit our saturated fat intake. This is an hypothesis that grew out of the observations of one very zealous University of Minnesota nutritionist in the 1950s, a fellow named Ancel Keys, who came up with this idea that dietary fat raised cholesterol, and it was raised cholesterol that caused heart disease. At the time there was effectively no meaningful experimental data to support–I’ll rephrase that: There was no experimental data to support that observation. It seemed plausible, though. It seemed plausible, compelling. Keys was a persuasive fellow. And by 1960 or so, the American Heart Association (AHA) got behind it in part because Keys and a fellow-proponent of this hypothesis, a cardiologist from Chicago named Jeremiah Stamler, got onto the AHA, got involved with an ad hoc committee, and were able to publish a report basically saying we should all cut our fat intake. This was 1961. Like I said, no data to support it; no experimental data at all. And once the AHA got behind it, it got a kind of believability. The attitude was: It’s probably right, and all we have to do is test it. Or, we’re going to believe it’s true, but we don’t have the data yet because we haven’t done the tests yet.

And researchers start doing the tests, experimental trials, taking a population. For instance, a famous study at the VA hospital in Los Angeles, where you randomize half of them to a cholesterol-lowering diet which is not actually low in fat, by the way–it’s low in saturated fat and high in polyunsaturated fat. And then the other half of your subjects eat a control diet and you look for heart disease over a number of years and see what happens. And trial after trial was sort of unable to prove the hypothesis true. But the more we studied it, the more people simply believed it must be true. And meanwhile, the AHA is pushing it; other observations are being compiled to support it even though in order to support it you have to ignore the observations that don’t support it. So, you pay attention to the positive evidence, ignore the negative evidence. One Scottish researcher who I interviewed memorably called this “Bing Crosby epidemiology” where you “accentuate the positive, eliminate the negative.” Basic human nature. But this is what happened. And as the AHA gets behind it, the journalists see the AHA as honest brokers of information on this, so they have no reason to doubt the AHA. And the AHA was honest brokers–they just were bad scientists. Or they were not scientists. So, then the press gets behind it, and as the press gets behind it, politicians begin to think maybe we should do something about it, and a Congressional subcommittee gets involved, run by George McGovern, that had originally been founded in the late 1960s to address hunger in America; and they did a lot of good things with school lunch programs and food stamps. And by the mid-1970s they were running out of things to do, so they decided: Since we’ve been dealing with under-nutrition, which is not enough food, they would get involved with over-nutrition, which is a problem of too much food and obesity and diabetes and heart disease. And they had one day of hearings, McGovern’s subcommittee, and they assign a former labor reporter from the Providence, RI, Journal to write the first dietary goals for the United States–the first document ever from a government body of any kind suggesting that a low fat diet is a healthy diet. And once McGovern comes out with this document, written by a former labor reporter who knew nothing about nutrition and health; now the USDA feels they have to get involved; and you get this kind of cascade or domino effect. To the point that by 1984 the National Institute of Health (NIH) holds a consensus conference saying that we have a consensus of opinion that we should all eat low fat diets, when they still don’t have a single meaningful experiment showing that a low fat diet or cholesterol lowering diet will reduce the risk of heart disease, or at least make you live longer. Because a few of the studies suggested that you could reduce the risk of heart disease but you would increase cancer. And not one study–the biggest study ever done, which was in Minnesota, actually suggested that if you put people on cholesterol-lowering diets you increase mortality; they had more deaths in the intervention group than the control group. (…)

Japanese women in Japan have very low rates of breast cancer. So when Japanese women come to the United States, by the second generation they have rates of breast cancer as high as any other ethnic group, and one possibility is it’s because they come over here and they eat more fat. But the problem with those observational studies, those comparisons, is you don’t know what you are looking at. So, you focus on fat because that’s what your hypothesis is about–and this is an endemic problem in public health–and you just don’t pay attention to anything else. So, sugar consumption is very low in Japan and very high here. So, maybe it’s sugar that’s the cause of heart disease, or the absence of sugar is the reason the Japanese are so relatively healthy; and if you don’t look at sugar, you don’t know.

{ Gary Taubes/EconTalk | Continue reading }

photo { Robert Mapplethorpe }

After four decades of largely unfulfilled hopes—Dec. 23 marks 40 years since President Nixon declared war on cancer—scientists have hit on a potential cure that few thought possible a few years ago: vaccines. If they succeed, cancer vaccines would revolutionize treatment. They could spell the end of chemotherapy and radiation, which can have horrific side effects, which tumor cells often become resistant to, and which often make so little difference it would be laughable were it not so tragic: last week, for instance, headlines touted two new drugs for metastatic breast cancer even though studies failed to show that they extend survival by a single day. Vaccines could make such “advances” a thing of the past. And they could make cancer as preventable, with a few jabs, as measles.

“Could” is the key word. Cancer vaccines are still being tested. Patients, doctors, and scientists know only too well that seemingly wondrous cancer therapies can flame out. But progress is accelerating. In 2010, the U.S. Food and Drug Administration approved the first-ever tumor vaccine, called Provenge, to treat prostate cancer. Scores of other vaccines are in the pipeline. Over the summer, researchers at the University of Pennsylvania unveiled what they call a cancer “breakthrough 20 years in the making”: a vaccine against chronic lymphocytic leukemia (CLL) that has brought about remissions of up to a year and counting—and which its inventors believe can be tweaked to attack lung cancer, ovarian cancer, myeloma, and melanoma. Vaccines against pancreatic and brain cancer are also being tested. “For the first time,” says Disis, who has a $7.9 million grant from the Pentagon to develop a preventive vaccine, “clinical trials [of cancer vaccines] are demonstrating anti-tumor efficacy in numbers of patients with cancer, not just one or two unique individuals.”

{ Newsweek | Continue reading }

Left-handers have been the subject of curiosity, stigma and even fear over the centuries. Researchers now, however, are recognizing the scientific importance of understanding why people use one hand or the other to write, eat or toss a ball.

Handedness, as the dominance of one hand over the other is called, provides a window into the way our brains are wired, experts say. And it may help shed light on disorders related to brain development, like dyslexia, schizophrenia and attention deficit hyperactivity disorder, or ADHD, which are more common in left-handed people.

About 10% of people are left-handed, according to expert estimates. Another 1% of the population is mixed-handed. What causes people not to favor their right hand is only partly due to genetics—even identical twins, who have 100% of the same genes, don’t always share handedness.

{ WSJ | Continue reading }

Brian Witcombe and Dan Meyer won an Ig Nobel prize for their extensive medical survey of sword swallowing injuries. Nearly half of the interviewed sword swallowers complained of sore throats, but more serious injuries included perforation of the gullet and intestinal bleeding. (…)

Toast has a tendency to land butter-side down because it rotates as it falls off the edge of the table. If the table was higher (three meters high, for example), the problem would disappear because the toast would be able to make a full rotation before hitting the floor.

{ The Soft Anonymous | Continue reading }

Imagine a scientist gently swabs your left nostril with a Q-tip and finds that your nose contains hundreds of species of bacteria. That in itself is no surprise; each of us is home to some 100 trillion microbes. But then she makes an interesting discovery: in your nose is a previously unknown species that produces a powerful new antibiotic. Her university licenses it to a pharmaceutical company; it hits the market and earns hundreds of millions of dollars. Do you deserve a cut of the profits? (…)

In recent years, scientists have discovered remarkable complexity and power in the microbes that live inside us. We depend on this so-called microbiome for our well-being: it helps break down our food, synthesize vitamins and shield against disease-causing germs. (…)

Someday we may get important clues to people’s health from a survey of their microbes. Professor Rhodes argues that this sort of information will deserve the same protection as information about our own genes. (…)

But that is only one side of the issue. As scientists get to know the microbiome better, they are also looking for new medical treatments: after all, most antibiotics were first discovered in bacteria and fungi.

{ NY Times | Continue reading }

photo { Roy DeCarava, Cab 173, New York, 1962 }

Walker and his team tried to measure how sleeping can help us to process bad experiences. (…)

The results show that during the REM sleep the part of the brain that processes the emotions (the amygdala) decreased its activity, so that the prefrontal cortex, linked to rational actions, probably weakened the impact of a bad experience. Also, they noticed a drop in the levels of brain chemicals that are linked to stress.

“Somewhere between the initial event and the later point of recollecting, the brain has performed an elegant trick of divorcing emotions from memory, so it’s no longer itself emotional,” Walker said.

{ United Academics | Continue reading }

Researchers are great at finding correlations between lifestyle and health. Here are four study results you’ve probably seen.

1. People who have a drink or two each day live longer.

2. People who own pets live longer.

3. People who exercise 20 minutes a day live longer.

4. Religious people live longer.

What do all four of those lifestyle choices have in common in terms of a possible root cause explanation? Read the list again and see if you can find it. (…) The pattern I noticed is that each of the lifestyle choices directly lowers stress by improving a person’s attitude.

My hypothesis is that stress is the root cause of most health problems.

{ Scott Adams | Continue reading }