The traditional view is that a human body is a collection of 10 trillion cells which are themselves the products of 23,000 genes. If the revolutionaries are correct, these numbers radically underestimate the truth. For in the nooks and crannies of every human being, and especially in his or her guts, dwells the microbiome: 100 trillion bacteria of several hundred species bearing 3m non-human genes. The biological Robespierres believe these should count, too; that humans are not single organisms, but superorganisms made up of lots of smaller organisms working together.
It might sound perverse to claim bacterial cells and genes as part of the body, but the revolutionary case is a good one. For the bugs are neither parasites nor passengers. They are, rather, fully paid-up members of a community of which the human “host” is but a single (if dominating) member. This view is increasingly popular: the world’s leading scientific journals, Nature and Science, have both reviewed it extensively in recent months. It is also important: it will help the science and practice of medicine (see article).
All in this together
The microbiome does many jobs in exchange for the raw materials and shelter its host provides. One is to feed people more than 10% of their daily calories. These are derived from plant carbohydrates that human enzymes are unable to break down. And not just plant carbohydrates. Mother’s milk contains carbohydrates called glycans which human enzymes cannot digest, but bacterial ones can.
This alone shows how closely host and microbiome have co-evolved over the years. But digestion is not the only nutritional service provided. The microbiome also makes vitamins, notably B2, B12 and folic acid. It is, moreover, capable of adjusting its output to its host’s needs and diet. The microbiomes of babies make more folic acid than do those of adults. And microbiomes in vitamin-hungry places like Malawi and rural Venezuela turn out more of these chemicals than do those in the guts of North Americans.
The microbiome also maintains the host’s health by keeping hostile interlopers at bay. An alien bug that causes diarrhoea, for instance, is as much an enemy of the microbiome as of the host. Both have an interest in zapping it. And both contribute to the task. Host and microbiome, then, are allies. But there is more to it than that. For the latest research shows their physiologies are linked in ways which make the idea of a human superorganism more than just a rhetorical flourish.
These links are most visible when they go wrong. A disrupted microbiome has been associated with a lengthening list of problems: obesity and its opposite, malnutrition; diabetes (both type-1 and type-2); atherosclerosis and heart disease; multiple sclerosis; asthma and eczema; liver disease; numerous diseases of the intestines, including bowel cancer; and autism. The details are often obscure, but in some cases it looks as if bugs are making molecules that help regulate the activities of human cells. If these signals go wrong, disease is the consequence. This matters because it suggests doctors have been looking in the wrong place for explanations of these diseases. It also suggests a whole new avenue for treatment. If an upset microbiome causes illness, settling it down might effect a cure.
Yogurt companies and health-food fanatics have been banging this drum for years. And in the case of at least one malady, irritable-bowel syndrome, they are right. So-called probiotics, a mixture of about half a dozen bacterial species found in yogurt, do act to calm this condition. But there is little evidence that consuming probiotics has the tonic effect on healthy people that certain adverts suggest.
A handful of doctors are taking a more fundamental approach to another microbiome-related disease, infection with Clostridium difficile. This bacterium, which causes life-threatening distension of the gut in some people who have been treated with antibiotics and thus had their microbiomes disrupted, is a bane of hospitals. It kills 14,000 people a year in America alone. But recent experiments have shown it can be eliminated by introducing, as an enema, the faeces of a healthy individual. “Stool transplants” are a pretty crude approach, to be sure, but the crucial point is that microbes are much easier to manipulate than human cells. For all the talk of superorganisms (and despite the yuck factor of what is being moved from one body to another), transplanting a microbiome is far easier than transplanting a heart or a kidney.
Disgusting but useful
Two other areas look promising. One is more sophisticated deployment of the humble antibiotic, arguably the pharma industry’s most effective invention. At the moment antibiotics are used mainly to kill infections. In the future they might have a more subtle use—to manipulate the mix of bugs within a human, so that good bugs spread at the expense of bad ones.
The other field that may be changed is genetics. Many of the diseases in which the microbiome is implicated seem to run in families. In some, such as heart disease, that is partly explained by known human genes. In a lot, though, most notably autism, the genetic link is obscure. This may be because geneticists have been looking at the wrong set of genes—the 23,000 rather than the 3m. For those 3m are still inherited. They are largely picked up from your mother during the messy process of birth. Though no clear example is yet known, it is possible that particular disease-inducing strains are being passed down the generations in this way.
As with all such upheavals, it is unclear where the microbiome revolution will end up. Doctors and biologists may truly come to think of people as superorganisms. Then again, they may not. What is clear, though, is that turning thinking inside out in this way is yielding new insights into seemingly intractable medical problems, and there is a good chance cures will follow. Vive la révolution!
Source: Modern medicine: Microbes maketh man | The Economist
Because the body’s systems are interconnected, changes in the eye can reflect those in the vascular, nervous and immune system, among others. And because the eyes are see-through in a way other organs aren’t, they offer a unique glimpse into the body. Blood vessels, nerves and tissue can all be viewed directly through the eye with specialized equipment.
The eyes are the window not only to the soul, but also to the health of the body. Shirley Wang on Lunch Break focuses on some of new research going on about the eye and what it means for seemingly unrelated disease.
With regular monitoring, eye doctors can be the first to spot certain medical conditions and can usher patients for further evaluation, potentially leading to earlier diagnosis and treatment. Clots in the tiny blood vessels of the retina can signal a risk for stroke, for example, and thickened blood-vessel walls along with narrowing of the vessels can signal high blood pressure. In some cases, examining the eye can help confirm some of the diagnoses or help differentiate disorders from each other.
“There’s no question the eye has always been the window to the body,” says Emily Chew, deputy director of the epidemiology division at the National Eye Institute. She adds, “Anybody with any visual changes…should be seeing someone right away.”
Scientists are working to advance their knowledge of what the eye can reveal about diseases. For instance, researchers are studying how dark spots on the back of the eye known as CHRPE, or congenital hypertrophy of the retinal pigment epithelium, are associated with certain forms of colon cancer, and how dementia-related changes are signaled in the eye, such as how the eye reacts to light. Other scientists, like Dr. Chew, are studying how to keep the eye healthier for longer, which could be good for the health of the eye as well as the rest of the body.
The eye’s job is to deliver vision by converting incoming light information into messages that the brain can understand. But problems in vision can indicate a problem outside of the eye itself.
The eyes can help predict stroke risk, particularly important to people with heart disease and other stroke risk factors. That is because blood clots in the arteries of the neck and head that might lead to stroke are often visible as retinal emboli, or clots, in the tiny blood vessels of the eye, according to the National Eye Institute.
The immune system’s interaction with the eyes can be telling, too, yielding information about autoimmune diseases or infections in the rest of the body. Sometimes eye symptoms may appear before others, like joint pain, in patients.
For instance, inflammation in the optic nerve can signal problems in an otherwise healthy, young person. Along with decreased vision and sometimes pain, it can suggest multiple sclerosis. If the optic disc, a portion of the optic nerve, is swollen, and the patient has symmetrical decreased field of vision, such as a decreased right visual field in both eyes, they may need an evaluation for a brain tumor—a rare circumstance.
If immune cells like white blood cells are seen floating in the vitreous of the eye, it could signal a local eye infection or one that is spread throughout the body.
Diabetes is one disease that can cause major changes in the eye. In diabetic retinopathy, a common cause of blindness, blood vessels hemorrhage and leak blood and fluid. When blood vessels don’t function properly, they can potentially cause eye tissue to be deprived of oxygen and to die, leaving permanent vision damage.
Also, in diabetic patients additional blood vessels may grow in the eye, anchoring themselves into the sticky gel known as the vitreous, which fills a cavity near the retina. This condition can cause further problems if the retina tears when it tries to separate from the vitreous—a common occurrence as people age—but is tangled by growth of new blood vessels.
Usually diabetic patients who come in for eye exams already know they have the disease, and the primary purpose of an eye exam is to make sure they don’t have diabetic retinopathy or, if they did have it, that the condition hasn’t progressed, say eye doctors like Dr. Ingvoldstad, a private practitioner at Midwest Eye Care in Omaha, Neb. But once in a while there is a patient who has noticed vision changes but didn’t realize he or she had diabetes until alerted during an eye exam that there were signs of the eye disease that is consistent with the condition, he says.
The American Academy of Ophthalmology recommends eye examinations whenever individuals notice any vision changes or injury. Adults with no symptoms or known risk factors for eye disease should get a base line exam by age 40 and return every two to four years for evaluations until their mid-50s. From 55 to 64, the AAO recommends exams every one to three years, and every one to two years for those 65 and older.
Source: What Your Eyes Reveal About Your Health – WSJ.com
After struggling for almost a minute in a November debate to come up with the third federal agency he’d eliminate should he win the Oval Office, Texas Gov. Rick Perry finally admitted he couldn’t remember.
While his campaign quickly tried to limit the damage, there had been earlier signs that Gov. Perry was in trouble that had little to do with his campaign war chest, his policies, or his personal charisma. Instead, they had everything to do with his pillow.
“We had a tired puppy,” one of Perry’s Republican allies told The New York Times after the governor had performed poorly in a string of earlier debates. Aides tried to rework his schedule in order for Governor Perry to get more hours of slumber, but it apparently wasn’t enough before that November night.
For most of us, it’s easy to see the stumble as nothing more than a memorable gaffe. Yet Governor Perry’s moment of forgetfulness should also serve as the sum of all fears for anyone who sees sleep as something that can be put off or overlooked without painful consequences. When a person lies down to sleep at night, the brain undergoes a process that is crucial to learning, memory, and performance in ways that scientists are only now beginning to understand. Though the exact mechanisms of the brain remain unclear, studies have suggested that time spent dozing has helped research subjects solve puzzles faster, pick up new skills with better results, and think more quickly on their feet.
Why does sleep help turn us into more competent versions of ourselves? Part of the answer is the simple fact that chronic sleep deprivation, which for most of us means routinely getting six or less hours of sleep each night, essentially makes us feel and act like we’re drunk. This breakdown most likely affects you even if you think you can function without sleep and not suffer the consequences. There are some that can stay awake longer, of course, but they remain relatively rare: in 2009, researchers at UC–San Francisco identified an unusual genetic mutation that allowed members of one family to routinely go with less than six hours of sleep with no clear tradeoffs in ability or health.
Dreamland by David K Randall
‘Dreamland: Adventures in the Strange Science of Sleep’ By David K. Randall. 304 pages. W. W. Norton. $25.95. (George Coppock / Getty Images)
A study in the journal Occupational and Environmental Medicine published in 2000 applies to the rest of us. Researchers gathered a group of subjects that included employees at a transportation company and members of the Australian Army. Each person was tested on his or her ability to drive in a simulated road test. As subjects went without sleeping, their reaction times slowed, their memories dulled, and their sense of time grew hazy. Soon, it was clear that those who had stayed awake for more than 17 straight hours were in worse shape than those with a blood alcohol content of 0.05 percent, the level that qualified as legally drunk in Australia.
But sleep’s benefits aren’t simply preventing slowing reaction times. Sleep also looks to bolster the brain’s ability to handle taxing mental loads. This even applies to naps. Researchers at the City University of New York, for example, gave test subjects a pair of objects and told them that they would be judged on their ability to remember them later. One group was given a 90-minute break to take a nap, while the other group spent that time awake watching a movie. Subjects came back to the testing room expecting to complete the simple memory puzzle. Researchers instead asked them to describe the relationships between the objects that made up each pair, rather them simply recall them.
[I]t was clear that those who had stayed awake for more than 17 straight hours were in worse shape than those with a blood alcohol content of 0.5 percent
The amount of time each subject slept determined how well he or she performed on the task. Subjects who were able to reach deeper stages of sleep demonstrated a better command of flexible thinking, a vital cognitive skill that allows us to apply old facts and information to new situations. It was as if sleep stretched the muscles of the brain, and it responded by bending its conception of reality in a way that let it arrive at a new vision. Other subjects in studies who were allowed to sleep have finished mazes faster, have become less emotional when confronted with disturbing images, and have remembered a longer list of words than their peers who hadn’t been allowed to doze off.
This has real-world applications outside of the research labs, of course. Athletes, for whom any slight change in ability can mean the difference between winning and losing, are turning to sleep as one of the last untapped advantages left in sports. Some Major League Baseball coaches, for instance, have instituted rules that players must get to the ballpark early to take naps before games, all in hopes that the edge from extra sleep will result in a team that plays consistently well. Airline pilots, military soldiers, long-haul truckers and others who work dangerous jobs, meanwhile, are also more likely to receive orders to boost their sleep before coming on duty.
It’s a requirement that seems particularly effective with pitchers, for whom sheer athleticism is only half of the battle. The other half is knowing the tendencies of your opponent—whether he will bite at a high curveball, or how often he swings at the first pitch. A pitcher who isn’t getting enough sleep has already lost the memory battle that he fights every time he is on the mound.
That’s exactly the kind of mental contest in which Governor Perry essentially forfeited that fateful night in November, as he continued to campaign at a pace that gave him little time for sleep. Not long after the debate, Sen. John McCain told CNN’s Wolf Blitzer that he had some advice for Governor Perry: get some sleep. “Every time I’ve made a serious political mistake … it’s been when I’m tired,” he said.
That, in fact, could be our new rallying cry: more zzzs, fewer oops.
David K. Randall is a senior reporter at Reuters. He has previously written for The New York Times, New York magazine, Forbes, and the Associated Press, covering topics ranging from financial fraud to a unicycle club that meets at Grant’s Tomb.
Source: Sleep Your Way to the Top: How Sleep Equals Success – The Daily Beast
Charles Darwin pointed to these vestiges of anatomy in humans and other animals as evidence for evolution. Eventually, by noting how the vestigial organs in one species were similar to functioning organs in other species, biologists concluded two otherwise dissimilar creatures must have shared a common ancestor. Here are five of the most notable vestigial organs in humans:
The Appendix: This small pouch attached to your large intestine, at the junction of the small intestine, no longer aids in digestion, and none of the 1 in 20 people who have one removed seems to miss it. In plant-eating vertebrates, it remains part of the digestive system. And a study in 2009 found that the human appendix might be useful, serving as an important storehouse for beneficial bacteria, which can’t wait for a chance a case of diarrhea so they can rush to the gut and save you.
The Tailbone: Grandpa didn’t have a tail, but if you go back far enough in the family tree, your ancestors did. Other mammals find their tails useful for balance, but when humans learned to walk, the tail because useless and evolution converted it to just some fused vertebrae we call a coccyx.
Male Nipples: This one might surprise you. Men have nipples because early on in the womb, the gender of a fetus could go either way. Essentially, every fetus starts out female. Eventually, testosterone causes a fetus to veer toward male or female. It’s worth noting that some men have been known to lactate, and men can get breast cancer.
Erector Pili and Body Hair: Goose bumps aren’t just to alert you of cold. And in many creatures, fear and confrontation cause muscle fibers called erector pili to activate, forcing hairs to stand up and make the animal appear larger and more threatening. That would’ve been useful to your distant ancestors, those hairy beasts!
Wisdom Teeth: Little more than a pain for many people, wisdom teeth probably once served a function, scientists figure. But the human jaw has become smaller over time and the wisdom teeth just have nowhere to grow. It’s also possible that dental hygiene is partly to blame. Before tooth brushing, a young adult would have lost many or most of his teeth, and the incoming wisdom teeth would have been timely.
Source: 5 Useless Body Parts | Vestigial Organs | LiveScience
It is now well known that spending too much time sitting down is bad for the heart, even if one takes regular exercise.
Now American scientists have tried to quantify exactly how risky it is to spend too long on the sofa.
By looking at a number of separate studies and pooling the results, they estimated that if people limited their television viewing to a maximum of two hours a day, from birth, they would live on average 1.4 years longer than they do now.
Peter Katzmarzyk and I-Min Lee from the Pennington Biomedical Research Centre in Baton Rouge, Louisiana, also looked at the effect of total sitting time (including television watching) on life expectancy, in an article published in the journal BMJ Open.
They estimated that if people limited their sitting time to three hours a day, their life expectancy would increase by two years on average.
They looked at two studies in which people were asked how much time they spent sitting.
In the first, the Canadian Fitness Survey, participants were asked how much of their total waking hours they spent sitting. It found almost 50 per cent admitted to spending at least half their time sitting down.
In the second, an American study, volunteers were asked how much of their leisure time they spent doing so. It found similar results – that just over 50 per cent spent at least half their free time sitting down.
These results chime with a previous finding that the average American adult spends 7.7 hours a day sitting down.
Katzmarzyk and Lee concluded: “The results of this study indicate that extended sitting time and TV viewing may have the potential to reduce life expectancy in the USA.”
They said “a significant shift” in people’s behaviour, regarding cutting down on television watching and sitting down, was required “to make demonstrable improvements in life expectancy”.
David Spiegelhalter, Professor of the Public Understanding of Risk at Cambridge University, agreed.
He said: “It seems plausible that if future generations moved around a bit more, then they might live longer on average.
“But very few of us currently spend less than three hours sitting each day, and so this seems a very optimistic target.”
Source: Limit TV watching to 2 hours to live longer, say scientists – Telegraph
Ever since the advent of the service industry, the nation has fallen in love with the swivel chair.
Study after study shows the UK is getting more sedentary in its working and home life.
Yet the dangers of sitting down for prolonged periods have also been well documented, with scientists saying there is a higher risk of obesity, Type 2 diabetes and heart disease. Now, in a report for the online journal BMJ Open, scientists say limiting the time we spend sitting to just three hours a day could add an extra two years to our life expectancy. Cutting daily TV viewing down to two hours could add on 1.4 years.
- Government figures suggest most adults now spend a large part of the day in sedentary pursuits
- And “significant proportions” sitting for more than five hours per day
- In 2010, a Weight Watchers UK Ltd found the average Briton spends an average of 14 hours and 39 minutes sitting down every day
So how can those that live a sedentary lifestyle slip the shackle of the swivel chair and snatch some extra time standing up?
It’s not just sitting down. Adopting any one posture for a long time is bad, says Jane White from the Institution of Occupational Safety and Health (IOSH).
“Some of the Met police recently collapsed at a passing out ceremony from standing up for too long. It’s being static that’s the health issue – it slows down the circulatory system, blood, oxygen and vital nutrients,” she says.
White notes that 7.6m working days are lost a year as result of musculoskeletal disorders in the UK.
With desk-based office jobs on the rise, IOSH “encourages more movements, more breaks, and taking time to consider health and wellbeing”, she says.
IOSH has walking lunch groups and yoga classes.
But White says other companies are more inventive.
“In one, people are encouraged to stand when they take a phone call – apparently it was sold on the idea it burnt more calories. Another company has a no internal email day, so people have to leave their desks to deliver messages within the organisation.
“We’ve been to another company with a boardroom with no table and chairs, so meetings don’t take so long. And we’ve had experience of offices having pedometers under desks – the British Heart Foundation has helped encourage that.”
Working off calories
- The average person burns 20 calories in 20 minutes when lying down – compared with 140 calories in a brisk walk
- 78 calories are burnt filing while standing up – or talking standing up – over 30 minutes
- An extra 26 calories are burnt photocopying for 10 minutes
Priya Dasoju, a professional adviser and chartered physiotherapist, suggests simple things like setting reminders on an Outlook calendar to move every 20 minutes, or using a printer further away.
While getting off the train one stop earlier, parking a little further afield, or choosing to stand up rather than sit down on a commute is all time well spent, she says.
More strategic measures could include walking meetings, or limiting meetings to 10 minute periods, Dasoju says.
In an ideal world, the physiotherapist advocates tailor-made work stations, but they would cost money.
There should be a cultural shift, she says.
“It’s not like bosses say, ‘make sure you keep moving to look after your back’, it is not really thought about. It is becoming more acceptable to go to the gym at lunch, but it needs to get to the point that it is frowned upon when people have lunch at their desks.
“There need to be exercise schemes, it needs to be part of inductions, rather than an aside. It has happened to a degree with flights which have got exercises on screens to prevent DVT,” she says.
Dr Sarah Jarvis, a presenter on the BBC’s One Show, says simple things like not storing items at the bottom of staircases – but taking items upstairs whenever they need to be moved – can make a big difference. As can parking far from the supermarket entrance.
“It’s about setting targets – for example if an errand is less than half a mile away, walk.
“If people burn, say, an extra 100 calories over the course of a day by doing small things, that’s a pound of weight in just over a month, which is not far away from a stone a year. Thinking of it like that can have an impact,” she says.
White says she also has some personal tips on how to keep active in front of the screen in the – somewhat unhelpfully named – sitting room.
“Personally I enjoy Wii or Xbox with the kids – it can be dancing to Michael Jackson.
“I know my other half likes having a spinning bike in the shed – so he can escape the kids watching EastEnders. Ultimately, it’s all about encouraging exercise and bringing it into mundane tasks at home,” she says.
BBC News – A sitting person’s guide to standing up
We all know when something is inflamed. But, what about inflammation on the inside of our bodies? Internal inflammation can happen for a host of different reasons: high temperatures when cooking food, eating processed foods, sugar, trans fats, etc. A high level of inflammation within the body can cause many health problems. An easy way to combat this? Eat more anti-inflammatory foods and eliminate the inflammatory ones.